1
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Fjelldal MA, Fritzén NR, Suominen KM, Lilley TM. Supersize me: hypotheses on torpor-assisted prehibernation fattening in a boreal bat. Biol Lett 2024; 20:20240291. [PMID: 39288816 DOI: 10.1098/rsbl.2024.0291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2024] [Revised: 07/08/2024] [Accepted: 08/07/2024] [Indexed: 09/19/2024] Open
Abstract
Hibernators face an energetic dilemma in the autumn at northern latitudes; while temperatures and food availability decrease, hibernating species need to build fat deposits to survive the winter. During this critical fattening phase, insectivorous boreal bats use torpor to build and conserve their reserves. However, we still know little about temporal variability in torpor use employed by bats during the prehibernation fattening period and how decreasing temperatures and food availability in combination with increasing individual body mass impact this. Here, we present two general hypotheses for explaining temporal torpor patterns observed in a boreal bat (Eptesicus nilssonii), in which torpor use (i) facilitates rapid mass gain or (ii) conserves stored body mass. Although temporally separated in our dataset, data on temperature, insect abundance and body mass throughout the prehibernation period indicate that E. nilssonii reaches the majority of its overwintering mass before the onset of increasing daytime and night-time torpor use. In combination with low food availability by this point in time, these observations suggest torpor expression may be intended to conserve gained reserves rather than facilitate mass gain. Our study is intended as a first proof of concept for disentangling temporal drivers of torpor in bats during the prehibernation fattening phase.
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Affiliation(s)
- Mari A Fjelldal
- Finnish Museum of Natural History, University of Helsinki, Helsinki, Finland
| | - Niclas R Fritzén
- Valsörarna Biological Station, Ostrobothnia Australis, Vasa, Finland
| | - Kati M Suominen
- Finnish Museum of Natural History, University of Helsinki, Helsinki, Finland
| | - Thomas M Lilley
- Finnish Museum of Natural History, University of Helsinki, Helsinki, Finland
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2
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Toshkova N, Zhelyzkova V, Reyes-Ruiz A, Haerens E, de Castro Deus M, Lacombe RV, Lecerf M, Gonzalez G, Jouvenet N, Planchais C, Dimitrov JD. Temperature sensitivity of bat antibodies links metabolic state of bats with antigen-recognition diversity. Nat Commun 2024; 15:5878. [PMID: 38997292 PMCID: PMC11245544 DOI: 10.1038/s41467-024-50316-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Accepted: 07/03/2024] [Indexed: 07/14/2024] Open
Abstract
The bat immune system features multiple unique properties such as dampened inflammatory responses and increased tissue protection, explaining their long lifespan and tolerance to viral infections. Here, we demonstrated that body temperature fluctuations corresponding to different physiological states in bats exert a large impact on their antibody repertoires. At elevated temperatures typical for flight, IgG from the bat species Myotis myotis and Nyctalus noctula show elevated antigen binding strength and diversity, recognizing both pathogen-derived antigens and autoantigens. The opposite is observed at temperatures reflecting inactive physiological states. IgG antibodies of human and other mammals, or antibodies of birds do not appear to behave in a similar way. Importantly, diversification of bat antibody specificities results in preferential recognition of damaged endothelial and epithelial cells, indicating an anti-inflammatory function. The temperature-sensitivity of bat antibodies is mediated by the variable regions of immunoglobulin molecules. Additionally, we uncover specific molecular features of bat IgG, such as low thermodynamic stability and implication of hydrophobic interactions in antigen binding as well as high prevalence of polyreactivity. Overall, our results extend the understanding of bat tolerance to disease and inflammation and highlight the link between metabolism and immunity.
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Affiliation(s)
- Nia Toshkova
- National Museum of Natural History, Bulgarian Academy of Sciences, Sofia, Bulgaria
- Institute of Biodiversity and Ecosystem Research, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Violeta Zhelyzkova
- National Museum of Natural History, Bulgarian Academy of Sciences, Sofia, Bulgaria
- Centre de Recherche des Cordeliers, INSERM, CNRS, Sorbonne Université, Université Paris Cité, Paris, France
| | - Alejandra Reyes-Ruiz
- Centre de Recherche des Cordeliers, INSERM, CNRS, Sorbonne Université, Université Paris Cité, Paris, France
| | - Eline Haerens
- Centre de Recherche des Cordeliers, INSERM, CNRS, Sorbonne Université, Université Paris Cité, Paris, France
| | - Marina de Castro Deus
- Centre de Recherche des Cordeliers, INSERM, CNRS, Sorbonne Université, Université Paris Cité, Paris, France
| | - Robin V Lacombe
- Centre de Recherche des Cordeliers, INSERM, CNRS, Sorbonne Université, Université Paris Cité, Paris, France
| | - Maxime Lecerf
- Centre de Recherche des Cordeliers, INSERM, CNRS, Sorbonne Université, Université Paris Cité, Paris, France
| | - Gaelle Gonzalez
- ANSES, INRAE, Ecole Nationale Vétérinaire d'Alfort, UMR Virologie, Laboratoire de Santé Animale, Maisons-Alfort, France
| | - Nolwenn Jouvenet
- Institut Pasteur, Université de Paris Cité, CNRS UMR3569, Virus Sensing and Signaling Unit, Paris, France
| | - Cyril Planchais
- Humoral Immunology Unit, Institut Pasteur, INSERM U1222, Université Paris Cité, Paris, France
| | - Jordan D Dimitrov
- Centre de Recherche des Cordeliers, INSERM, CNRS, Sorbonne Université, Université Paris Cité, Paris, France.
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3
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Turbill C, Walker M, Boardman W, Martin JM, McKeown A, Meade J, Welbergen JA. Torpor use in the wild by one of the world's largest bats. Proc Biol Sci 2024; 291:20241137. [PMID: 38981525 PMCID: PMC11335021 DOI: 10.1098/rspb.2024.1137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2024] [Revised: 06/11/2024] [Accepted: 06/12/2024] [Indexed: 07/11/2024] Open
Abstract
Torpor is widespread among bats presumably because most species are small, and torpor greatly reduces their high mass-specific resting energy expenditure, especially in the cold. Torpor has not been recorded in any bat species larger than 50 g, yet in theory could be beneficial even in the world's largest bats (flying-foxes; Pteropus spp.) that are exposed to adverse environmental conditions causing energy bottlenecks. We used temperature telemetry to measure body temperature in wild-living adult male grey-headed flying-foxes (P. poliocephalus; 799 g) during winter in southern Australia. We found that all individuals used torpor while day-roosting, with minimum body temperature reaching 27°C. Torpor was recorded following a period of cool, wet and windy weather, and on a day with the coldest maximum air temperature, suggesting it is an adaptation to reduce energy expenditure during periods of increased thermoregulatory costs and depleted body energy stores. A capacity for torpor among flying-foxes has implications for understanding their distribution, behavioural ecology and life history. Furthermore, our discovery increases the body mass of bats known to use torpor by more than tenfold and extends the documented use of this energy-saving strategy under wild conditions to all bat superfamilies, with implications for the evolutionary maintenance of torpor among bats and other mammals.
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Affiliation(s)
- Christopher Turbill
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, New South Wales, Australia
- School of Science, Western Sydney University, Penrith, New South Wales, Australia
| | - Melissa Walker
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, New South Wales, Australia
| | - Wayne Boardman
- School of Animal and Veterinary Sciences, University of Adelaide, Roseworthy, South Australia, Australia
| | - John M. Martin
- Taronga Conservation Society, Mosman, New South Wales, Australia
| | - Adam McKeown
- CSIRO Land & Water, Atherton, Queensland, Australia
| | - Jessica Meade
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, New South Wales, Australia
| | - Justin A. Welbergen
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, New South Wales, Australia
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4
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Keicher L, Shipley JR, Dietzer MT, Wikelski M, Dechmann DKN. Heart rate monitoring reveals differential seasonal energetic trade-offs in male noctule bats. Proc Biol Sci 2024; 291:20240855. [PMID: 38981523 PMCID: PMC11334998 DOI: 10.1098/rspb.2024.0855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Revised: 06/07/2024] [Accepted: 06/07/2024] [Indexed: 07/11/2024] Open
Abstract
Understanding how animals meet their daily energy requirements is critical in our rapidly changing world. Small organisms with high metabolic rates can conserve stored energy when food availability is low or increase energy intake when energetic requirements are high, but how they balance this in the wild remains largely unknown. Using miniaturized heart rate transmitters, we continuously quantified energy expenditure, torpor use and foraging behaviour of free-ranging male bats (Nyctalus noctula) in spring and summer. In spring, bats used torpor extensively, characterized by lowered heart rates and consequently low energy expenditures. In contrast, in summer, bats consistently avoided torpor, even though they could have used this low-energy mode. As a consequence, daytime heart rates in summer were three times as high compared with the heart rates in spring. Daily energy use increased by 42% during summer, despite lower thermogenesis costs at higher ambient temperatures. Likely, as a consequence, bats nearly doubled their foraging duration. Overall, our results indicate that summer torpor avoidance, beneficial for sperm production and self-maintenance, comes with a high energetic cost. The ability to identify and monitor such vulnerable energetic life-history stages is particularly important to predict how species will deal with increasing temperatures and changes in their resource landscapes.
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Affiliation(s)
- Lara Keicher
- Max Planck Institute of Animal Behavior, Am Obstberg 1, Radolfzell78315, Germany
- Department of Biology, University of Konstanz, Universitätsstraße 10, Konstanz78457, Germany
| | - J. Ryan Shipley
- WLS Institute for Snow and Avalanche Research, Flüelastraße 11, DavosCH-7260, Switzerland
| | - Melina T. Dietzer
- Department of Wildlife Ecology and Management, University of Freiburg, Tennenbacher Straße 4, Freiburg79106, Germany
| | - Martin Wikelski
- Max Planck Institute of Animal Behavior, Am Obstberg 1, Radolfzell78315, Germany
- Department of Biology, University of Konstanz, Universitätsstraße 10, Konstanz78457, Germany
| | - Dina K. N. Dechmann
- Max Planck Institute of Animal Behavior, Am Obstberg 1, Radolfzell78315, Germany
- Department of Biology, University of Konstanz, Universitätsstraße 10, Konstanz78457, Germany
- Cluster for the Advanced Study of Collective Behaviour, University of Konstanz, Universitätsstraße 10, Konstanz78457, Germany
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5
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McGuire LP, Leys R, Webber QMR, Clerc J. Heterothermic Migration Strategies in Flying Vertebrates. Integr Comp Biol 2023; 63:1060-1074. [PMID: 37279461 DOI: 10.1093/icb/icad053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 05/25/2023] [Accepted: 05/29/2023] [Indexed: 06/08/2023] Open
Abstract
Migration is a widespread and highly variable trait among animals. Population-level patterns arise from individual-level decisions, including physiological and energetic constraints. Many aspects of migration are influenced by behaviors and strategies employed during periods of stopover, where migrants may encounter variable or unpredictable conditions. Thermoregulation can be a major cost for homeotherms which largely encounter ambient temperatures below the lower critical temperature during migration, especially during the rest phase of the daily cycle. In this review we describe the empirical evidence, theoretical models, and potential implications of bats and birds that use heterothermy to reduce thermoregulatory costs during migration. Torpor-assisted migration is a strategy described for migrating temperate insectivorous bats, whereby torpor can be used during periods of inactivity to drastically reduce thermoregulatory costs and increase net refueling rate, leading to shorter stopover duration, reduced fuel load requirement, and potential consequences for broad-scale movement patterns and survival. Hummingbirds can adopt a similar strategy, but most birds are not capable of torpor. However, there is an increasing recognition of the use of more shallow heterothermic strategies by diverse bird species during migration, with similarly important implications for migration energetics. A growing body of published literature and preliminary data from ongoing research indicate that heterothermic migration strategies in birds may be more common than traditionally appreciated. We further take a broad evolutionary perspective to consider heterothermy as an alternative to migration in some species, or as a conceptual link to consider alternatives to seasonal resource limitations. There is a growing body of evidence related to heterothermic migration strategies in bats and birds, but many important questions related to the broader implications of this strategy remain.
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Affiliation(s)
- Liam P McGuire
- Department of Biology, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Ryan Leys
- Department of Biology, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Quinn M R Webber
- Department of Integrative Biology, University of Guelph,Guelph, ON N1G 2W1, Canada
| | - Jeff Clerc
- National Renewable Energy Laboratory, Golden, CO 80401, USA
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6
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Schoen A, Hölzer M, Müller MA, Wallerang KB, Drosten C, Marz M, Lamp B, Weber F. Functional comparisons of the virus sensor RIG-I from humans, the microbat Myotis daubentonii, and the megabat Rousettus aegyptiacus, and their response to SARS-CoV-2 infection. J Virol 2023; 97:e0020523. [PMID: 37728614 PMCID: PMC10653997 DOI: 10.1128/jvi.00205-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Accepted: 07/09/2023] [Indexed: 09/21/2023] Open
Abstract
IMPORTANCE A common hypothesis holds that bats (order Chiroptera) are outstanding reservoirs for zoonotic viruses because of a special antiviral interferon (IFN) system. However, functional studies about key components of the bat IFN system are rare. RIG-I is a cellular sensor for viral RNA signatures that activates the antiviral signaling chain to induce IFN. We cloned and functionally characterized RIG-I genes from two species of the suborders Yangochiroptera and Yinpterochiroptera. The bat RIG-Is were conserved in their sequence and domain organization, and similar to human RIG-I in (i) mediating virus- and IFN-activated gene expression, (ii) antiviral signaling, (iii) temperature dependence, and (iv) recognition of RNA ligands. Moreover, RIG-I of Rousettus aegyptiacus (suborder Yinpterochiroptera) and of humans were found to recognize SARS-CoV-2 infection. Thus, members of both bat suborders encode RIG-Is that are comparable to their human counterpart. The ability of bats to harbor zoonotic viruses therefore seems due to other features.
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Affiliation(s)
- Andreas Schoen
- Institute for Virology, FB10-Veterinary Medicine, Justus-Liebig University, Giessen, Germany
| | - Martin Hölzer
- RNA Bioinformatics and High-Throughput Analysis, Friedrich Schiller University Jena, Jena, Germany
- European Virus Bioinformatics Center, Jena, Germany
| | - Marcel A. Müller
- German Centre for Infection Research (DZIF), Partner Sites Giessen and Charité, Berlin, Germany
- Institute of Virology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Kai B. Wallerang
- Institute for Virology, FB10-Veterinary Medicine, Justus-Liebig University, Giessen, Germany
| | - Christian Drosten
- European Virus Bioinformatics Center, Jena, Germany
- German Centre for Infection Research (DZIF), Partner Sites Giessen and Charité, Berlin, Germany
- Institute of Virology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Manja Marz
- RNA Bioinformatics and High-Throughput Analysis, Friedrich Schiller University Jena, Jena, Germany
- European Virus Bioinformatics Center, Jena, Germany
| | - Benjamin Lamp
- Institute for Virology, FB10-Veterinary Medicine, Justus-Liebig University, Giessen, Germany
| | - Friedemann Weber
- Institute for Virology, FB10-Veterinary Medicine, Justus-Liebig University, Giessen, Germany
- European Virus Bioinformatics Center, Jena, Germany
- German Centre for Infection Research (DZIF), Partner Sites Giessen and Charité, Berlin, Germany
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7
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Power ML, Ransome RD, Riquier S, Romaine L, Jones G, Teeling EC. Hibernation telomere dynamics in a shifting climate: insights from wild greater horseshoe bats. Proc Biol Sci 2023; 290:20231589. [PMID: 37817598 PMCID: PMC10565397 DOI: 10.1098/rspb.2023.1589] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2023] [Accepted: 09/10/2023] [Indexed: 10/12/2023] Open
Abstract
Hibernation is linked with various hypotheses to explain the extended lifespan of hibernating mammals compared with their non-hibernating counterparts. Studies on telomeres, markers of ageing and somatic maintenance, suggest telomere shortening slows during hibernation, and lengthening may reflect self-maintenance with favourable conditions. Bats in temperate zones adjust body temperatures during winter torpor to conserve energy and exploit mild conditions for foraging. Climate change may impact the hibernation cycle of bats, but more research is needed regarding the role of telomeres in understanding their response to a changing climate. Here, relative telomere length (rTL) was measured in the long-lived greater horseshoe bat Rhinolophus ferrumequinum (n = 223 individuals) over three winters, considering climatic conditions. Cross-sectional analyses revealed between-individual variation in rTL with a strong year effect, likely linked to varying weather conditions and foraging success. Additionally, within-individual increases of rTL occurred in 51% of consecutive measurements, with evidence of increasing telomerase expression during hibernation in this species. These findings highlight the beneficial effects of hibernation on telomeres and potential consequences of changing climatic conditions for long-lived temperate bats. Understanding the interplay between hibernation, telomeres, and climate can provide insights into the adaptive capacity and survival of bat populations facing environmental challenges.
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Affiliation(s)
- Megan L Power
- School of Biology and Environmental Science, Science Centre West, University College Dublin, Belfield, Dublin 4, Republic of Ireland
| | - Roger D Ransome
- School of Biological Sciences, University of Bristol, Life Sciences Building, 24 Tyndall Avenue, Bristol BS8 1TQ, UK
| | - Sébastien Riquier
- School of Biology and Environmental Science, Science Centre West, University College Dublin, Belfield, Dublin 4, Republic of Ireland
| | - Luke Romaine
- School of Biological Sciences, University of Bristol, Life Sciences Building, 24 Tyndall Avenue, Bristol BS8 1TQ, UK
| | - Gareth Jones
- School of Biological Sciences, University of Bristol, Life Sciences Building, 24 Tyndall Avenue, Bristol BS8 1TQ, UK
| | - Emma C Teeling
- School of Biology and Environmental Science, Science Centre West, University College Dublin, Belfield, Dublin 4, Republic of Ireland
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8
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Fjelldal MA, Muller AS, Ratikainen II, Stawski C, Wright J. The small-bat-in-summer paradigm: Energetics and adaptive behavioural routines of bats investigated through a stochastic dynamic model. J Anim Ecol 2023; 92:2078-2093. [PMID: 37661664 DOI: 10.1111/1365-2656.13999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Accepted: 08/16/2023] [Indexed: 09/05/2023]
Abstract
Strong seasonality at high latitudes represents a major challenge for many endotherms as they must balance survival and reproduction in an environment that varies widely in food availability and temperature. To avoid energetic mismatches caused by limited foraging time and stochastic weather conditions, bats employ the energy-saving state of torpor during summer to save accumulated energy reserves. However, at high-latitude small-bats-in-summer face a particular challenge: as nocturnal foragers, they rely on the darkness at night to avoid predators and/or interspecific competition, but live in an environment with short, light summer nights, and even a lack of true night at the northernmost distributions of some bat species. To predict optimal behaviour in relation to latitudinal variation in diurnal cycles, we constructed a stochastic dynamic programming model of bats living at high latitudes. Using a stochastic dynamic programming framework with values that are representative for our study system, we show that individual energetic reserves are a strong driver of daytime use of torpor and night-time foraging behaviour alike, with these linked effects being both temperature- and photoperiod-dependent. We further used the model to predict survival probabilities at five locations across a latitudinal gradient (60.1° N to 70.9° N), finding that combinations of photoperiod and temperature conditions limited population distributions in the model. To verify our model results, we compared predictions for optimal decisions with our own empirical data collected on northern bats (Eptesicus nilssonii) from two latitudes in Norway. The similarities between our predictions and observations provide strong evidence that this model framework incorporates the most important drivers of diurnal decision-making in bat physiology and behaviour. Comparing empirical data and model predictions also revealed that bats facing lighter night conditions further north restrict their mass gain, which strengthens the hypothesis that predation threat is a main driver of bat nocturnality. Our model findings regarding state-dependent decisions in bats should contribute to the understanding of how bats cope with the summer challenges at high latitudes.
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Affiliation(s)
- Mari Aas Fjelldal
- Department of Biology, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
| | - Amandine Sophie Muller
- Department of Biology, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
| | - Irja Ida Ratikainen
- Department of Biology, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
| | - Clare Stawski
- Department of Biology, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
- School of Science, Technology and Engineering, University of the Sunshine Coast (USC), Maroochydore DC, Queensland, Australia
| | - Jonathan Wright
- Department of Biology, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
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9
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Sato T, Sugiyama T, Sekijima T. Mating in the cold. Prolonged sperm storage provides opportunities for forced copulation by male bats during winter. Front Physiol 2023; 14:1241470. [PMID: 37745243 PMCID: PMC10511888 DOI: 10.3389/fphys.2023.1241470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Accepted: 08/28/2023] [Indexed: 09/26/2023] Open
Abstract
In a wide range of heterothermic mammals, hibernation interrupts the reproductive cycle by forcing reproductive delays. In hibernating bats with delayed fertilization, an opportunity for sperm competition is enhanced by extending a time-window between copulations and fertilization. In order to achieve greater fertilization success, males are expected to show adaptations for sperm competition by increasing their opportunities for mating over an extended period. We aimed to clarify the physiological and behavioral characteristics of male bats experiencing increased risks of sperm competition. We investigated the characteristics of the reproductive cycle of the little horseshoe bat (Rhinolophus cornutus), and examined whether males retain reproductive physiology related to sexual behavior, and attempt to copulate with females even during the hibernation period. Field observations and histological examinations of the reproductive cycle confirmed that females, having mated in the autumn, store spermatozoa in the uterus during hibernation and give birth in the early summer to just one offspring per year, thus males face a low certainty of successful fertilization. Although their testes regressed rapidly and their testosterone levels were lower during winter than in autumn, males stored motile spermatozoa in their cauda epididymides from autumn throughout the winter. During hibernation, we found that males occasionally aroused from torpor and attempted to mate forcibly with torpid females. Forced copulations appear to increase a male's chances of obtaining a mate while avoiding pre-copulatory female choice. Epididymal sperm storage could be advantageous for males in allowing them to extend their potential mating period even though their testes have regressed. We also found that some hibernating nulliparous females were ready for fertilization in spring after hibernation, whereas few parous females appeared in the same roost. In contrast to males, forced copulations would be maladaptive for females because they cannot opt for higher-quality males while in torpor. Females that have experienced sexual coercion when young may subsequently avoid hibernacula where adult males are present.
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Affiliation(s)
- Takahiro Sato
- Graduate School of Technology, Industrial, and Social Sciences, Tokushima University, Tokushima, Japan
- Faculty of Agriculture, Niigata University, Niigata, Japan
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10
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Pekar JE, Lytras S, Ghafari M, Magee AF, Parker E, Havens JL, Katzourakis A, Vasylyeva TI, Suchard MA, Hughes AC, Hughes J, Robertson DL, Dellicour S, Worobey M, Wertheim JO, Lemey P. The recency and geographical origins of the bat viruses ancestral to SARS-CoV and SARS-CoV-2. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.12.548617. [PMID: 37502985 PMCID: PMC10369958 DOI: 10.1101/2023.07.12.548617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
The emergence of SARS-CoV in 2002 and SARS-CoV-2 in 2019 has led to increased sampling of related sarbecoviruses circulating primarily in horseshoe bats. These viruses undergo frequent recombination and exhibit spatial structuring across Asia. Employing recombination-aware phylogenetic inference on bat sarbecoviruses, we find that the closest-inferred bat virus ancestors of SARS-CoV and SARS-CoV-2 existed just ~1-3 years prior to their emergence in humans. Phylogeographic analyses examining the movement of related sarbecoviruses demonstrate that they traveled at similar rates to their horseshoe bat hosts and have been circulating for thousands of years in Asia. The closest-inferred bat virus ancestor of SARS-CoV likely circulated in western China, and that of SARS-CoV-2 likely circulated in a region comprising southwest China and northern Laos, both a substantial distance from where they emerged. This distance and recency indicate that the direct ancestors of SARS-CoV and SARS-CoV-2 could not have reached their respective sites of emergence via the bat reservoir alone. Our recombination-aware dating and phylogeographic analyses reveal a more accurate inference of evolutionary history than performing only whole-genome or single gene analyses. These results can guide future sampling efforts and demonstrate that viral genomic fragments extremely closely related to SARS-CoV and SARS-CoV-2 were circulating in horseshoe bats, confirming their importance as the reservoir species for SARS viruses.
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Affiliation(s)
- Jonathan E Pekar
- Bioinformatics and Systems Biology Graduate Program, University of California San Diego, La Jolla, CA 92093, USA
- Department of Biomedical Informatics, University of California San Diego, La Jolla, CA 92093, USA
- These authors contributed equally
| | - Spyros Lytras
- Medical Research Council-University of Glasgow Centre for Virus Research, Glasgow, UK
- These authors contributed equally
| | - Mahan Ghafari
- Department of Biology, University of Oxford, Oxford, UK
| | - Andrew F Magee
- Department of Human Genetics, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Edyth Parker
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Jennifer L Havens
- Bioinformatics and Systems Biology Graduate Program, University of California San Diego, La Jolla, CA 92093, USA
| | | | - Tetyana I Vasylyeva
- Department of Medicine, University of California San Diego, La Jolla, CA 92093, USA
| | - Marc A Suchard
- Department of Human Genetics, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095, USA
- Department of Biostatistics, Fielding School of Public Health, University of California Los Angeles, Los Angeles, CA 90095, USA
- Department of Computational Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Alice C Hughes
- School of Biological Sciences, University of Hong Kong, Hong Kong
- China Biodiversity Green Development Foundation, Beijing, China
| | - Joseph Hughes
- Medical Research Council-University of Glasgow Centre for Virus Research, Glasgow, UK
| | - David L Robertson
- Medical Research Council-University of Glasgow Centre for Virus Research, Glasgow, UK
- These authors jointly supervised the work
| | - Simon Dellicour
- Spatial Epidemiology Lab (SpELL), Université Libre de Bruxelles, CP160/12, 50 av. FD Roosevelt, 1050, Bruxelles, Belgium
- Department of Microbiology, Immunology and Transplantation, Rega Institute, Laboratory for Clinical and Epidemiological Virology, KU Leuven, Leuven, Belgium
- These authors jointly supervised the work
| | - Michael Worobey
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ 85721, USA
- These authors jointly supervised the work
| | - Joel O Wertheim
- Department of Medicine, University of California San Diego, La Jolla, CA 92093, USA
- These authors jointly supervised the work
| | - Philippe Lemey
- Department of Microbiology, Immunology and Transplantation, Rega Institute, Laboratory for Clinical and Epidemiological Virology, KU Leuven, Leuven, Belgium
- These authors jointly supervised the work
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11
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Pronounced differences in heart rate and metabolism distinguish daily torpor and short-term hibernation in two bat species. Sci Rep 2022; 12:21721. [PMID: 36522368 PMCID: PMC9755216 DOI: 10.1038/s41598-022-25590-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 12/01/2022] [Indexed: 12/23/2022] Open
Abstract
Torpor, and its differential expression, is essential to the survival of many mammals and birds. Physiological characteristics of torpor appear to vary between those species that express strict daily heterothermy and those capable of multiday hibernation, but comparisons are complicated by the temperature-dependence of variables. Previous reviews have compared these different torpor strategies by measuring the depth and duration of torpor in multiple species. However, direct comparison of multiple physiological parameters under similar thermal conditions are lacking. Here, we quantified three physiological variables; body temperature, metabolic rate (MR) and heart rate (HR) of two small heterothermic bats (daily heterotherm Syconycteris australis, and hibernator Nyctophilus gouldi) under comparable thermal conditions and torpor bout durations. When normothermic and resting both MR and HR were similar for the two species. However, during torpor the minimum HR was more than fivefold higher, and minimum MR was 6.5-fold higher for the daily heterotherm than for the hibernator at the same subcutaneous Tb (16 ± 0.5 °C). The data show that the degree of heterothermy defined using Tb is not necessarily a precise proxy for physiological capacity during torpor in these bats and is unlikely to reveal accurate energy budgets. Our study provides evidence supporting a distinction between daily torpor in a daily heterotherm and short term torpor in a hibernator, at least within the Chiroptera with regard to these physiological variables. This exists even when individuals display the same degree of Tb reduction, which has clear implications for the modelling of their energy expenditure.
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12
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Marsden GE, Schoeman MC, Vosloo D. Rewarming rates of seven insectivorous bat species along an altitudinal gradient in South Africa. J Therm Biol 2022; 110:103341. [DOI: 10.1016/j.jtherbio.2022.103341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 08/11/2022] [Accepted: 09/20/2022] [Indexed: 10/14/2022]
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13
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Sørås R, Fjelldal MA, Bech C, van der Kooij J, Skåra KH, Eldegard K, Stawski C. State dependence of arousal from torpor in brown long-eared bats (Plecotus auritus). J Comp Physiol B 2022; 192:815-827. [PMID: 35972527 PMCID: PMC9550697 DOI: 10.1007/s00360-022-01451-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 06/08/2022] [Accepted: 07/19/2022] [Indexed: 11/02/2022]
Abstract
To cope with periods of low food availability and unsuitable environmental conditions (e.g., short photoperiod or challenging weather), many heterothermic mammals can readily go into torpor to save energy. However, torpor also entails several potential costs, and quantitative energetics can, therefore, be influenced by the individual state, such as available energy reserves. We studied the thermal energetics of brown long-eared bats (Plecotus auritus) in the northern part of its distributional range, including torpor entry, thermoregulatory ability during torpor and how they responded metabolically to an increasing ambient temperature (Ta) during arousal from torpor. Torpor entry occurred later in bats with higher body mass (Mb). During torpor, only 10 out of 21 bats increased oxygen consumption (V̇O2) to a greater extent above the mean torpor metabolic rates (TMR) when exposed to low Ta. The slope of the torpid thermoregulatory curve was shallower than that of resting metabolic rate (RMR) during normothermic conditions, indicating a higher thermal insulation during torpor. During exposure to an increasing Ta, all bats increased metabolic rate exponentially, but the bats with higher Mb aroused at a lower Ta than those with lower Mb. In bats with low Mb, arousal was postponed to an Ta above the lower critical temperature of the thermoneutral zone. Our results demonstrate that physiological traits, which are often considered fixed, can be more flexible than previously assumed and vary with individual state. Thus, future studies of thermal physiology should to a greater extent take individual state-dependent effects into account.
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Affiliation(s)
- Rune Sørås
- Department of Biology, Norwegian University of Science and Technology, 7491, Trondheim, NO, Norway.
| | - Mari Aas Fjelldal
- Department of Biology, Norwegian University of Science and Technology, 7491, Trondheim, NO, Norway
| | - Claus Bech
- Department of Biology, Norwegian University of Science and Technology, 7491, Trondheim, NO, Norway
| | - Jeroen van der Kooij
- Nature Education, Research and Consultancy van der Kooij, Rudsteinveien 67, 1480, Slattum, NO, Norway
| | - Karoline H Skåra
- Department of Biology, Norwegian University of Science and Technology, 7491, Trondheim, NO, Norway
- Centre for Fertility and Health, Norwegian Institute of Public Health, Skøyen, P.O. Box 222, Oslo, 0213, NO, Norway
| | - Katrine Eldegard
- Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, Box 5003, 1433, Ås, NO, Norway
| | - Clare Stawski
- Department of Biology, Norwegian University of Science and Technology, 7491, Trondheim, NO, Norway
- School of Science, Technology and Engineering, University of the Sunshine Coast, Maroochydore DC, QLD, 4558, Australia
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14
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Măntoiu DŞ, Mirea IC, Şandric IC, Cîşlariu AG, Gherghel I, Constantin S, Moldovan OT. Bat dynamics modelling as a tool for conservation management in subterranean environments. PLoS One 2022; 17:e0275984. [PMID: 36264951 PMCID: PMC9584375 DOI: 10.1371/journal.pone.0275984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Accepted: 09/26/2022] [Indexed: 11/18/2022] Open
Abstract
Bat species inhabit subterranean environments (e.g., caves and mines) in small areas with specific microclimatic conditions, during various periods of their life cycle. Bats can be negatively influenced by microclimatic changes within their roosts if optimal habitat patches become unavailable. Therefore, proper management solutions must be applied for the conservation of vulnerable bat populations, especially in show caves. We have pursued an ensemble species distribution modelling approach in subterranean environments to identify sensible patches for bats. Using multi-annual temperature monitoring and bat distribution surveys performed within ten caves and mines, including show caves, we modelled relevant habitat patches for five bat species. The temperature-based variables generated from this approach proved to be effective when processed via species distribution models, which generated optimal validation results, even for bats that were heavily clustered in colonies. Management measures are proposed for each show cave to help in long-time conservation of hibernation and maternity colonies. These measures include creating suitable microclimatic patches within the caves by ecological reconstruction measures, tourist management practices in relation to bats, and show cave fitting recommendations. This approach has never been performed at this scale due to the complex geostatistical challenges involving subterranean environment mapping and can be further used as best practice guidelines for future conservation projects.
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Affiliation(s)
| | - Ionuţ Cornel Mirea
- Department of Geospeleology and Paleontology, “Emil Racoviță” Institute of Speleology, Bucharest, Romania
- Romanian Institute of Science and Technology, Cluj-Napoca, Romania
| | - Ionuţ Cosmin Şandric
- Faculty of Geography, Department of Environmental Studies, University of Bucharest, Bucharest, Romania
| | - Alina Georgiana Cîşlariu
- Faculty of Biology, Department of Botany and Microbiology, University of Bucharest, Bucharest, Romania
| | - Iulian Gherghel
- Department of Exact Sciences and Natural Sciences, Institute of Interdisciplinary Research, “Alexandru Ioan Cuza” University of Iaşi, Iaşi, Romania
- Faculty of Natural and Agricultural Sciences, Ovidius University Constanţa, Constanţa, Romania
- Department of Biology, Case Western Reserve University, Cleveland, OH, United States of America
| | - Silviu Constantin
- Department of Geospeleology and Paleontology, “Emil Racoviță” Institute of Speleology, Bucharest, Romania
- Romanian Institute of Science and Technology, Cluj-Napoca, Romania
| | - Oana Teodora Moldovan
- “Emil Racoviță” Institute of Speleology—Cluj Department, Cluj-Napoca, Romania
- Romanian Institute of Science and Technology, Cluj-Napoca, Romania
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15
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Harding CD, Yovel Y, Peirson SN, Hackett TD, Vyazovskiy VV. Re-examining extreme sleep duration in bats: implications for sleep phylogeny, ecology, and function. Sleep 2022; 45:zsac064. [PMID: 35279722 PMCID: PMC9366634 DOI: 10.1093/sleep/zsac064] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 02/17/2022] [Indexed: 11/23/2022] Open
Abstract
Bats, quoted as sleeping for up to 20 h a day, are an often used example of extreme sleep duration amongst mammals. Given that duration has historically been one of the primary metrics featured in comparative studies of sleep, it is important that species specific sleep durations are well founded. Here, we re-examined the evidence for the characterization of bats as extreme sleepers and discuss whether it provides a useful representation of the sleep behavior of Chiroptera. Although there are a wealth of activity data to suggest that the diurnal cycle of bats is dominated by rest, estimates of sleep time generated from electrophysiological analyses suggest considerable interspecific variation, ranging from 83% to a more moderate 61% of the 24 h day spent asleep. Temperature-dependent changes in the duration and electroencephalographic profile of sleep suggest that bats represent a unique model for investigating the relationship between sleep and torpor. Further sources of intra-specific variation in sleep duration, including the impact of artificial laboratory environments and sleep intensity, remain unexplored. Future studies conducted in naturalistic environments, using larger sample sizes and relying on a pre-determined set of defining criteria will undoubtedly provide novel insights into sleep in bats and other species.
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Affiliation(s)
- Christian D Harding
- Department of Physiology Anatomy and Genetics, Sir Jules Thorn Sleep and Circadian Neuroscience Institute, University of Oxford, Oxford, UK
- The Kavli Institute for Nanoscience Discovery, Oxford, UK
| | - Yossi Yovel
- School of Zoology, Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, Israel
- Sagol School of Neuroscience, Tel-Aviv University, Tel-Aviv, Israel
| | - Stuart N Peirson
- The Kavli Institute for Nanoscience Discovery, Oxford, UK
- Nuffield Department of Clinical Neurosciences, Sir Jules Thorn Sleep and Circadian Neuroscience Institute, University of Oxford, Oxford, UK
| | | | - Vladyslav V Vyazovskiy
- Department of Physiology Anatomy and Genetics, Sir Jules Thorn Sleep and Circadian Neuroscience Institute, University of Oxford, Oxford, UK
- The Kavli Institute for Nanoscience Discovery, Oxford, UK
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16
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Flexible energy-saving strategies in female temperate-zone bats. J Comp Physiol B 2022; 192:805-814. [PMID: 35939092 PMCID: PMC9550788 DOI: 10.1007/s00360-022-01452-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 07/06/2022] [Accepted: 07/19/2022] [Indexed: 12/02/2022]
Abstract
Torpor is characterized by an extreme reduction in metabolism and a common energy-saving strategy of heterothermic animals. Torpor is often associated with cold temperatures, but in the last decades, more diverse and flexible forms of torpor have been described. For example, tropical bat species maintain a low metabolism and heart rate at high ambient and body temperatures. We investigated whether bats (Nyctalus noctula) from the cooler temperate European regions also show this form of torpor with metabolic inhibition at high body temperatures, and whether this would be as pronounced in reproductive as in non-reproductive bats. We simultaneously measured metabolic rate, heart rate, and skin temperature in non-reproductive and pregnant females at a range of ambient temperatures. We found that they can decouple metabolic rate and heart rate from body temperature: they maintained an extremely low metabolism and heart rate when exposed to ambient temperatures changing from 0 to 32.5 °C, irrespective of reproductive status. When we simulated natural temperature conditions, all non-reproductive bats used torpor throughout the experiment. Pregnant bats used variable strategies from torpor, to maintaining normothermy, or a combination of both. Even a short torpor bout during the day saved up to 33% of the bats' total energy expenditure. Especially at higher temperatures, heart rate was a much better predictor of metabolic rate than skin temperature. We suggest that the capability to flexibly save energy across a range of ambient temperatures within and between reproductive states may be an important ability of these bats and possibly other temperate-zone heterotherms.
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17
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Balzer EW, Grottoli AD, Burns LE, Broders HG. Active season body mass patterns of little brown and northern myotis bats. Ecol Evol 2022. [DOI: 10.1002/ece3.9230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Affiliation(s)
- Evan W. Balzer
- Department of Biology University of Waterloo Waterloo Ontario Canada
| | - Adam D. Grottoli
- Department of Biology University of Waterloo Waterloo Ontario Canada
| | - Lynne E. Burns
- Environment and Climate Change Canada Edmonton Alberta Canada
| | - Hugh G. Broders
- Department of Biology University of Waterloo Waterloo Ontario Canada
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18
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Barratt AE, Gonsalves L, Turbill C. Winter torpor and activity patterns of a fishing bat ( Myotis macropus) in a mild climate. J Mammal 2022. [DOI: 10.1093/jmammal/gyac061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Small insectivorous bats often enter a state of torpor, a controlled, reversible decrease in body temperature and metabolic rate. Torpor provides substantial energy savings and is used more extensively during periods of low temperature and reduced prey availability. We studied torpor use and activity of a small (10.1 ± 0.4 g) fishing bat, Myotis macropus, during winter in a mild climate in Australia. We predicted that the thermal stability of water would make foraging opportunities in winter more productive and consistent in a riparian habitat compared to a woodland habitat, and therefore, fishing bats would use torpor less than expected during winter compared to other bats. Using temperature-sensitive radio transmitters, we recorded the skin temperature of 12 adult (6 M, 6 F) bats over 161 bat-days (13.4 ± 5.4 days per bat) during Austral winter (late May to August), when daily air temperature averaged 6.2–18.2°C. Bats used torpor every day, with bouts lasting a median of 21.3 h and up to 144.6 h. Multiday torpor bouts were more common in females than males. Arousals occurred just after sunset and lasted 3.5 ± 2.9 h. Arousals tended to be longer in males than females and to occur on warmer evenings, suggesting some winter foraging and perhaps male harem territoriality or other mating-related activity was occurring. The extensive use of torpor by M. macropus during relatively mild winter conditions when food is likely available suggests torpor might function to minimize the risks of mortality caused by activity and to increase body condition for the upcoming breeding season.
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Affiliation(s)
- Alice E Barratt
- Hawkesbury Institute for the Environment and School of Science, Western Sydney University, Hawkesbury Campus , Richmond, New South Wales 2753 , Australia
| | - Leroy Gonsalves
- Forest Science Unit, New South Wales Department of Primary Industries , Parramatta, New South Wales 2150 , Australia
| | - Christopher Turbill
- Hawkesbury Institute for the Environment and School of Science, Western Sydney University, Hawkesbury Campus , Richmond, New South Wales 2753 , Australia
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19
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Fjelldal MA, Sørås R, Stawski C. Universality of torpor expression in bats. Physiol Biochem Zool 2022; 95:326-339. [DOI: 10.1086/720273] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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20
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Adam ML, de Assis Rocha Pessoa L, de Lima ARB, Bernard E. DNA damage as indicator of the environmental vulnerability of bats in Brazil's Caatinga drylands. ENVIRONMENTAL MONITORING AND ASSESSMENT 2022; 194:277. [PMID: 35288796 DOI: 10.1007/s10661-022-09906-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Accepted: 02/25/2022] [Indexed: 06/14/2023]
Abstract
Brazil's Caatinga drylands is under extensive environmental deterioration, with 38% of its natural cover already lost. There is a need for a better understanding of the effects of such degradation on Caatinga's rich and singular biota. Bats form a large part of this biota, and are pointed as good bioindicators. Here, we used the micronucleus test -an easy-to-use, accessible and cost-effective in vivo approach- to detect DNA damage in cells from bats of different species and feeding habits in three protected areas in the Caatinga, comparing them with samples from an industrial sugarcane plantation. We hypothesized that environmental disturbance would reflect in DNA damage, with lower levels of damage in the less disturbed protected areas. The frequency of micronucleated cells differed significantly between sites and feeding habits (carnivores > insectivores > frugivores > nectarivores > hematophagous) but did not differ between sexes. Alarmingly, the highest levels of DNA damage were in two strictly protected areas (Seridó and Raso da Catarina Ecological Stations). Glossophaga and Anoura were the genera with more damaged cells, and had, respectively, 1.48 and 3.53 times more micronucleated cells (average of 19.33 and 22.67 cells, respectively) than individuals from the same genera from the area with least damaged cells (average of 7.80 and 5.00 cells, respectively). Our analysis is a warning call for an in-depth investigation on the effects of both genotoxic contamination and environmental stressors on bats and other species in Brazil's Caatinga, including the role that historical human-induced processes -like the intense use of agrochemicals- may have had in the region.
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Affiliation(s)
- Mônica Lúcia Adam
- Laboratory of Evolutionary and Environmental Genomics - LAGEA, Universidade Federal de Pernambuco, Recife, PE, Brazil
| | - Letícia de Assis Rocha Pessoa
- Laboratório de Ciência Aplicada à Conservação da Biodiversidade, Departmento de Zoologia, Centro de Biociências, Universidade Federal de Pernambuco, Recife, PE, Brazil
| | | | - Enrico Bernard
- Laboratório de Ciência Aplicada à Conservação da Biodiversidade, Departmento de Zoologia, Centro de Biociências, Universidade Federal de Pernambuco, Recife, PE, Brazil.
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21
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Muñoz-Garcia A, Ben-Hamo M, Pilosof S, Williams JB, Korine C. Habitat aridity as a determinant of the trade-off between water conservation and evaporative heat loss in bats. J Comp Physiol B 2022; 192:325-333. [PMID: 35037994 DOI: 10.1007/s00360-021-01425-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Revised: 11/29/2021] [Accepted: 12/20/2021] [Indexed: 11/26/2022]
Abstract
The maintenance of water balance in arid environments might represent a formidable challenge for Chiroptera, since they have high surface-to-volume ratios. In deserts, bats conserve water, for example, using daily torpor, but they also might experience episodic heat bouts, when they may need to increase total evaporative water loss (TEWL) to thermoregulate. We hypothesized that in bats, habitat aridity and its variability determine a trade-off between water conservation and thermoregulation via evaporative means. To test this hypothesis, we collated data from the literature of 22 species of bats on TEWL, body temperature and resting metabolic rate, in torpor and euthermy. We also collected data on ambient temperature (Ta) and precipitation of the locations where bats were captured, calculated an aridity index, and built an index of variability of the environment. After correcting for phylogeny, we found that, as aridity and variability of the environment increased, bats had lower values of TEWL, but the rate at which TEWL increases with Ta was higher, supporting our hypothesis. These results suggest that at high Ta there is a trade-off between water conservation and evaporative heat loss in bats. The evolution of physiological mechanisms that allow water conservation and tolerance to conditions of high Ta without access to free water might thus be crucial to explain the distribution of desert bats.
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Affiliation(s)
- Agustí Muñoz-Garcia
- Department of Evolution, Ecology and Organismal Biology, Ohio State University at Mansfield, 1730 University Dr., Mansfield, OH, 44906, USA.
| | - Miriam Ben-Hamo
- Mitrani Department of Desert Ecology, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, 84990, Midreshet Ben-Gurion, Israel
| | - Shai Pilosof
- Mitrani Department of Desert Ecology, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, 84990, Midreshet Ben-Gurion, Israel
| | - Joseph B Williams
- Aronoff Laboratory, Department of Evolution, Ecology and Organismal Biology, Ohio State University, 318 W 12th Ave., Columbus, OH, 43210, USA
| | - Carmi Korine
- Mitrani Department of Desert Ecology, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, 84990, Midreshet Ben-Gurion, Israel
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22
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Chenery M, Geiser F, Stawski C. OUP accepted manuscript. J Mammal 2022; 103:826-834. [PMID: 36110387 PMCID: PMC9469929 DOI: 10.1093/jmammal/gyac022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Accepted: 02/08/2022] [Indexed: 11/14/2022] Open
Abstract
Insectivorous bats are particularly susceptible to heat loss due to their relatively large surface area to volume ratio. Therefore, to maintain a high normothermic body temperature, bats require large amounts of energy for thermoregulation. This can be energetically challenging for small bats during cold periods as heat loss is augmented and insect prey is reduced. To conserve energy many bats enter a state of torpor characterized by a controlled reduction of metabolism and body temperature in combination with selecting roosts based upon thermal properties. Our study aimed to quantify torpor patterns and roost preferences of free-ranging little forest bats (Vespadelus vulturnus) during winter to identify physiological and behavioral mechanisms used by this species for survival of the cold season. All bats captured were male (body mass 4.9 ± 0.7 g, n = 6) and used torpor on every day monitored, with bouts lasting up to 187.58 h (mean = 35.5 ± 36.7 h, n = 6, total number of samples [N] = 61). Torpor bout duration was significantly correlated with daily minimum and maximum ambient temperature, mean skin temperature, insect mass, and body mass of individuals and the multiday torpor bouts recorded in the cold qualify as hibernation. The lowest skin temperature recorded was 5.2°C, which corresponded to the lowest ambient temperature measurement of −5.8°C. Most bats chose tall, large, live Eucalyptus trees for roosting and to leave their roost for foraging on warmer days. Many individuals often switched roosts (every 3–5 days) and movements increased as spring approached (every 1–2 days). Our data suggest that V. vulturnus are capable of using the environmental temperature to gauge potential foraging opportunities and as a cue to reenter torpor when conditions are unsuitable. Importantly, frequent use of torpor and appropriate roost selection form key roles in the winter survival of these tiny bats.
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Affiliation(s)
- Melissa Chenery
- Centre for Behavioural and Physiological Ecology, Zoology, University of New England, Armidale, NSW 2351, Australia
| | - Fritz Geiser
- Centre for Behavioural and Physiological Ecology, Zoology, University of New England, Armidale, NSW 2351, Australia
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23
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McGuire LP, Fuller NW, Dzal YA, Haase CG, Klüg-Baerwald BJ, Silas KA, Plowright RK, Lausen CL, Willis CKR, Olson SH. Interspecific variation in evaporative water loss and temperature response, but not metabolic rate, among hibernating bats. Sci Rep 2021; 11:20759. [PMID: 34675252 PMCID: PMC8531132 DOI: 10.1038/s41598-021-00266-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Accepted: 10/08/2021] [Indexed: 11/30/2022] Open
Abstract
Hibernation is widespread among mammals in a variety of environmental contexts. However, few experimental studies consider interspecific comparisons, which may provide insight into general patterns of hibernation strategies. We studied 13 species of free-living bats, including populations spread over thousands of kilometers and diverse habitats. We measured torpid metabolic rate (TMR) and evaporative water loss (two key parameters for understanding hibernation energetics) across a range of temperatures. There was no difference in minimum TMR among species (i.e., all species achieved similarly low torpid metabolic rate) but the temperature associated with minimum TMR varied among species. The minimum defended temperature (temperature below which TMR increased) varied from 8 °C to < 2 °C among species. Conversely, evaporative water loss varied among species, with species clustered in two groups representing high and low evaporative water loss. Notably, species that have suffered population declines due to white-nose syndrome fall in the high evaporative water loss group and less affected species in the low evaporative water loss group. Documenting general patterns of physiological diversity, and associated ecological implications, contributes to broader understanding of biodiversity, and may help predict which species are at greater risk of environmental and anthropogenic stressors.
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Affiliation(s)
- Liam P McGuire
- Department of Biology, University of Waterloo, 200 University Ave W, Waterloo, ON, N2L 3G1, Canada.
- Department of Biological Sciences, Texas Tech University, 2901 Main St, Lubbock, TX, 79409, USA.
| | - Nathan W Fuller
- Department of Biological Sciences, Texas Tech University, 2901 Main St, Lubbock, TX, 79409, USA
- Nongame and Rare Species Program, Texas Parks and Wildlife, Austin, TX, 78744, USA
| | - Yvonne A Dzal
- Department of Biology, University of Winnipeg, 515 Portage Ave, Winnipeg, MB, R3B 2E9, Canada
| | - Catherine G Haase
- Department of Microbiology and Immunology, Montana State University, PO Box 173520, Bozeman, MT, 59717, USA
- Department of Biology, Austin Peay State University, PO Box 4718, Clarkesville, TN, 37044, USA
| | - Brandon J Klüg-Baerwald
- Department of Biology, University of Regina, 3737 Wascana Parkway, Regina, SK, S4S 0A2, Canada
| | - Kirk A Silas
- Wildlife Conservation Society, Health Program, 2300 Southern Blvd, Bronx, NY, 10460, USA
| | - Raina K Plowright
- Department of Microbiology and Immunology, Montana State University, PO Box 173520, Bozeman, MT, 59717, USA
| | - Cori L Lausen
- Wildlife Conservation Society Canada, Bat Program, PO Box 606, Kaslo, BC, V0G 1M0, Canada
| | - Craig K R Willis
- Department of Biology, University of Winnipeg, 515 Portage Ave, Winnipeg, MB, R3B 2E9, Canada
| | - Sarah H Olson
- Wildlife Conservation Society, Health Program, 2300 Southern Blvd, Bronx, NY, 10460, USA
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24
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Skåra KH, Bech C, Fjelldal MA, van der Kooij J, Sørås R, Stawski C. Energetics of whiskered bats in comparison to other bats of the family Vespertilionidae. Biol Open 2021; 10:271095. [PMID: 34338281 PMCID: PMC8353265 DOI: 10.1242/bio.058640] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 06/14/2021] [Indexed: 11/20/2022] Open
Abstract
Bats inhabit a variety of climate types, ranging from tropical to temperate zones, and environmental differences may therefore affect the basal metabolic rate (BMR) of bats from different populations. In the present study, we provide novel data on the energetics of whiskered bats (Myotis mystacinus), which is the smallest species within Chiroptera measured to date. We investigated the thermoregulatory strategies of M. mystacinus close to the northern limits of this species' distribution range and compared these data to other vespertilionid bats living in different climates. As mammals living in colder areas experience elevated thermoregulatory costs, often leading to an increase in BMR, we hypothesised that BMR of this northern population of whiskered bats would be higher than that of bats from climates with warm environmental temperatures. From a systematic literature search we obtained BMR estimates (N=47) from 24 species within Vespertilionidae. Our metabolic measurements of M. mystacinus in Norway (body mass of 4.4 g; BMR of 1.48 ml O2 g-1 h-1) were not different from other vespertilionid bats, based on the allometric equation obtained from the systematic literature search. Further, there was no effect of environmental temperature on BMR within Vespertilionidae. How these tiny bats adapt metabolically to high latitude living is thus still an open question. Bats do have a suite of physiological strategies used to cope with the varying climates which they inhabit, and one possible factor could be that instead of adjusting BMR they could express more torpor. This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Karoline H Skåra
- Department of Biology, Norwegian University of Science and Technology, Trondheim NO-7491, Norway
| | - Claus Bech
- Department of Biology, Norwegian University of Science and Technology, Trondheim NO-7491, Norway
| | - Mari Aas Fjelldal
- Department of Biology, Norwegian University of Science and Technology, Trondheim NO-7491, Norway
| | | | - Rune Sørås
- Department of Biology, Norwegian University of Science and Technology, Trondheim NO-7491, Norway
| | - Clare Stawski
- Department of Biology, Norwegian University of Science and Technology, Trondheim NO-7491, Norway
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Fumagalli MR, Zapperi S, La Porta CAM. Role of body temperature variations in bat immune response to viral infections. J R Soc Interface 2021; 18:20210211. [PMID: 34314652 DOI: 10.1098/rsif.2021.0211] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The ability of bats to coexist with viruses without being harmed is an interesting issue that is still under investigation. Here we use a mathematical model to show that the pattern of body temperature variations observed in bats between day and night is responsible for their ability to keep viruses in check. From the dynamical systems point of view, our model displays an intriguing quasi-periodic behaviour that might be relevant in making the system robust by avoiding viral escape due to perturbations in the body temperature cycle.
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Affiliation(s)
- Maria Rita Fumagalli
- Center for Complexity and Biosystems, Department of Environmental Science and Policy, University of Milan, Via Celoria 26, 20133 Milano, Italy.,CNR - Consiglio Nazionale delle Ricerche, Biophysics Institute, Via De Marini 6, 16149 Genova, Italy
| | - Stefano Zapperi
- Center for Complexity and Biosystems, Department of Physics, University of Milan, Via Celoria 16, 20133 Milano, Italy.,CNR - Consiglio Nazionale delle Ricerche, ICMATE, Via R. Cozzi 53, 20125 Milano, Italy
| | - Caterina A M La Porta
- Center for Complexity and Biosystems, Department of Environmental Science and Policy, University of Milan, Via Celoria 26, 20133 Milano, Italy.,CNR - Consiglio Nazionale delle Ricerche, Biophysics Institute, Via De Marini 6, 16149 Genova, Italy
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26
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Webber QMR, McGuire LP. Heterothermy, body size, and locomotion as ecological predictors of migration in mammals. Mamm Rev 2021. [DOI: 10.1111/mam.12263] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Quinn M. R. Webber
- Cognitive and Behavioural Ecology Interdisciplinary Program Memorial University of Newfoundland 232 Elizabeth Ave St. John’s NLA1B 3X9Canada
- Department of Ecology and Evolutionary Biology University of Colorado Boulder Ramaley N122 Boulder CO80309‐0334USA
| | - Liam P. McGuire
- Department of Biology University of Waterloo 200 University Avenue West Waterloo ONN2L 3G1Canada
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27
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Bergeson SM, Brigham RM, O’Keefe JM. Free-ranging bats alter thermoregulatory behavior in response to reproductive stage, roost type, and weather. J Mammal 2021. [DOI: 10.1093/jmammal/gyab049] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Abstract
Heterotherms vary their use of torpor and choice of refugia to deal with energetic stresses such as reproductive activity and extreme weather. We hypothesized that a temperate-region bat would vary its use of heterothermy in response to air temperature but use of torpor would also be influenced by reproductive stage and roost choice. To test this hypothesis, we collected data on skin temperatures of female Indiana bats (Myotis sodalis) carrying temperature-sensitive radiotransmitters during the summers of 2013–2015. We also measured internal temperatures and external characteristics of roosts used by these bats. We analyzed the influence of daytime air temperature, roost canopy closure, roost type, and bat reproductive stage, on daily heterothermy index and torpor characteristics of 17 bats during 103 full roost days (data collected consistently from when a bat entered its roost in the morning to when it emerged at night). Our data showed that Indiana bat heterothermy was influenced by reproductive stage, roost choice, and weather. Although they used torpor, pregnant bats were the least heterothermic (daily heterothermy index = 3.3 ± 0.6°C SE), followed by juvenile bats (5.6 ± 0.5°C), lactating bats (5.7 ± 0.5°C), and one postlactating bat (13.2 ± 1.6°C). Air temperature also influenced heterothermy of pregnant bats less than bats of other reproductive stages. Thermoregulatory strategies varied on a continuum from use of normothermia in warm roosts to use of long and deep bouts of torpor in cool roosts. The thermoregulatory strategy used seemed to be determined by potential reproductive costs of torpor and energetic consequences of weather. Because Indiana bats used different degrees of heterothermy throughout the summer maternity season, managers should offer maternity colonies an array of refugia to facilitate varying behaviors in response to weather and energetic demands.
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Affiliation(s)
- Scott M Bergeson
- Department of Biology, Purdue University Fort Wayne, Fort Wayne, IN 46805, USA
- Center for Bat Research, Outreach, and Conservation, Indiana State University, Terre Haute, IN 47809, USA
| | - R Mark Brigham
- Department of Biology, University of Regina, Regina, SK S4S 0A2,Canada
| | - Joy M O’Keefe
- Department of Natural Resources and Environmental Sciences, University of Illinois, Urbana, IL 61801, USA
- Center for Bat Research, Outreach, and Conservation, Indiana State University, Terre Haute, IN 47809, USA
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28
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Smeraldo S, Bosso L, Salinas‐Ramos VB, Ancillotto L, Sánchez‐Cordero V, Gazaryan S, Russo D. Generalists yet different: distributional responses to climate change may vary in opportunistic bat species sharing similar ecological traits. Mamm Rev 2021. [DOI: 10.1111/mam.12247] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Sonia Smeraldo
- Wildlife Research Unit Dipartimento di Agraria Università degli Studi di Napoli Federico II Via Università n. 100 80055 Portici Napoli Italy
| | - Luciano Bosso
- Wildlife Research Unit Dipartimento di Agraria Università degli Studi di Napoli Federico II Via Università n. 100 80055 Portici Napoli Italy
| | - Valeria B. Salinas‐Ramos
- Wildlife Research Unit Dipartimento di Agraria Università degli Studi di Napoli Federico II Via Università n. 100 80055 Portici Napoli Italy
| | - Leonardo Ancillotto
- Wildlife Research Unit Dipartimento di Agraria Università degli Studi di Napoli Federico II Via Università n. 100 80055 Portici Napoli Italy
| | - Víctor Sánchez‐Cordero
- Laboratorio de Sistemas de Información Geográfica Departamento de Zoología Instituto de Biología Universidad Nacional Autónoma de México Av. Universidad 04510 Ciudad de México Mexico
| | - Suren Gazaryan
- Institute of Ecology of Mountain Territories RAS Armand 37A360000 Nalchik Russia
| | - Danilo Russo
- Wildlife Research Unit Dipartimento di Agraria Università degli Studi di Napoli Federico II Via Università n. 100 80055 Portici Napoli Italy
- School of Biological Sciences University of Bristol 24 Tyndall Avenue BristolBS8 1TQUK
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29
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Torquetti CG, Guimarães ATB, Soto-Blanco B. Exposure to pesticides in bats. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 755:142509. [PMID: 33032135 DOI: 10.1016/j.scitotenv.2020.142509] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 09/15/2020] [Accepted: 09/16/2020] [Indexed: 06/11/2023]
Abstract
Bats provide a variety of ecological services that are essential to the integrity of ecosystems. Indiscriminate use of pesticides has been a threat to biodiversity, and the exposure of bats to these xenobiotics is a threat to their populations. This study presents a review of articles regarding the exposure of bats to pesticides published in the period from January 1951 to July 2020, addressing the temporal and geographical distribution of research, the studied species, and the most studied classes of pesticides. The research was concentrated in the 1970s and 1980s, mostly in the Northern Hemisphere, mainly in the USA. Of the total species in the world, only 5% of them have been studied, evaluating predominantly insectivorous species of the Family Vespertilionidae. Insecticides, mainly organochlorines, were the most studied pesticides. Most research was observational, with little information available on the effects of pesticides on natural bat populations. Despite the advances in analytical techniques for detecting contaminants, the number of studies is still insufficient compared to the number of active ingredients used. The effects of pesticides on other guilds and tropical species remain poorly studied. Future research should investigate the effects of pesticides, especially in sublethal doses causing chronic exposure. It is crucial to assess the impact of these substances on other food guilds and investigate how natural populations respond to the exposure to mixtures of pesticides found in the environment.
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Affiliation(s)
- Camila Guimarães Torquetti
- Departamento de Clínica e Cirurgia Veterinárias, Escola de Veterinária, Universidade Federal de Minas Gerais (UFMG), Avenida Antônio Carlos 6627, Belo Horizonte, MG 30123-970, Brazil
| | - Ana Tereza Bittencourt Guimarães
- Laboratório de Investigações Biológicas, Centro de Ciências Biológicas e da Saúde, Universidade Estadual do Oeste do Paraná, Rua Universitária 2069, Cascavel, PR 85819-110, Brazil
| | - Benito Soto-Blanco
- Departamento de Clínica e Cirurgia Veterinárias, Escola de Veterinária, Universidade Federal de Minas Gerais (UFMG), Avenida Antônio Carlos 6627, Belo Horizonte, MG 30123-970, Brazil.
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Węgiel A, Grzywiński W, Kosicki JZ, Tryjanowski P, Nowak J, Węgiel J. Long-term population trends of Rhinolophus hipposideros and Myotis myotis in Poland. THE EUROPEAN ZOOLOGICAL JOURNAL 2021. [DOI: 10.1080/24750263.2021.2006324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
Affiliation(s)
- A. Węgiel
- Faculty of Forestry and Wood Technology, Poznań University of Life Sciences, Poland
| | - W. Grzywiński
- Faculty of Forestry and Wood Technology, Poznań University of Life Sciences, Poland
| | - J. Z. Kosicki
- Department of Avian Biology & Ecology, Faculty of Biology, Adam Mickiewicz University, Poland
| | - P. Tryjanowski
- Institute of Zoology, Poznań University of Life Sciences, Poland
- Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Czech Republic
| | | | - J. Węgiel
- Faculty of Forestry and Wood Technology, Poznań University of Life Sciences, Poland
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Body Size Variation in Italian Lesser Horseshoe Bats Rhinolophus hipposideros over 147 Years: Exploring the Effects of Climate Change, Urbanization and Geography. BIOLOGY 2020; 10:biology10010016. [PMID: 33396640 PMCID: PMC7824098 DOI: 10.3390/biology10010016] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 12/24/2020] [Accepted: 12/26/2020] [Indexed: 11/17/2022]
Abstract
Body size in animals commonly shows geographic and temporal variations that may depend upon several environmental drivers, including climatic conditions, productivity, geography and species interactions. The topic of body size trends across time has gained momentum in recent years since this has been proposed as a third universal response to climate change along with changes in distribution and phenology. However, disentangling the genuine effects of climate change from those of other environmental factors is often far from trivial. In this study, we tested a set of hypotheses concerning body size variation across time and space in Italian populations of a rhinolophid bat, the lesser horseshoe bat Rhinolophus hipposideros. We examined forearm length (FAL) and cranial linear traits in a unique historical collection of this species covering years from 1869 to 2016, representing, to the best of our knowledge, the longest time series ever considered in a morphological assessment of a bat species. No temporal changes occurred, rejecting the hypotheses that body size varied in response to climate change or urbanization (light pollution). We found that FAL increased with latitude following a Bergmann's rule trend, whereas the width of upper incisors, likely a diet-related trait, showed an opposite pattern which awaits explanation. We also confirmed that FAL is sexually dimorphic in this species and ruled out that insularity has any detectable effect on the linear traits we considered. This suggests that positive responses of body size to latitude do not mean per se that concurring temporal responses to climate change are also expected. Further investigations should explore the occurrence of these patterns over larger spatial scales and more species in order to detect the existence of general patterns across time and space.
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McClure ML, Crowley D, Haase CG, McGuire LP, Fuller NW, Hayman DTS, Lausen CL, Plowright RK, Dickson BG, Olson SH. Linking surface and subterranean climate: implications for the study of hibernating bats and other cave dwellers. Ecosphere 2020. [DOI: 10.1002/ecs2.3274] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Affiliation(s)
- Meredith L. McClure
- Conservation Science Partners 11050 Pioneer Trail Suite 202 Truckee California96161USA
| | - Daniel Crowley
- Department of Microbiology and Immunology Montana State University 109 Lewis Hall Bozeman Montana59717USA
| | - Catherine G. Haase
- Department of Microbiology and Immunology Montana State University 109 Lewis Hall Bozeman Montana59717USA
| | - Liam P. McGuire
- Department of Biological Sciences Texas Tech University 2901 Main Street Lubbock Texas79409USA
| | - Nathan W. Fuller
- Department of Biological Sciences Texas Tech University 2901 Main Street Lubbock Texas79409USA
| | - David T. S. Hayman
- mEpiLab Hopkirk Research Institute Massey University Palmerston North4442New Zealand
| | - Cori L. Lausen
- Wildlife Conservation Society Canada Kaslo British ColumbiaV0G 1M0Canada
| | - Raina K. Plowright
- Department of Microbiology and Immunology Montana State University 109 Lewis Hall Bozeman Montana59717USA
| | - Brett G. Dickson
- Conservation Science Partners 11050 Pioneer Trail Suite 202 Truckee California96161USA
- Landscape Conservation Initiative School of Earth and Sustainability Northern Arizona University Flagstaff Arizona86001USA
| | - Sarah H. Olson
- Wildlife Conservation Society Health Program Bronx New York10460USA
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33
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Martínková N, Baird SJE, Káňa V, Zima J. Bat population recoveries give insight into clustering strategies during hibernation. Front Zool 2020; 17:26. [PMID: 32884575 PMCID: PMC7465407 DOI: 10.1186/s12983-020-00370-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 08/13/2020] [Indexed: 01/29/2023] Open
Abstract
BACKGROUND Behaviour during hibernation contributes to energy conservation in winter. Hibernating bats select roosts with respect to physiological and environmental stressors, available local microclimate and species-specific requirements. RESULTS We found that, in the period between 1977 and 2018, hibernating Myotis myotis and Rhinolophus hipposideros bats showed exponential population growth. The growth rates, corrected for local winter seasonal severity and winter duration, were equal to 10 and 13%, respectively. While R. hipposideros only utilised the thermally stable and, at survey time, warmer corridors in the hibernaculum, an increasing proportion of M. myotis roosted in the thermally stable corridors as their abundance increased. About 14% of all hibernating M. myotis displayed solitary roosting, irrespective of other covariates. Those bats that clustered together formed progressively larger clusters with increasing abundance, particularly in cold corridors. We found no statistically significant relationship for clustering behaviour or cluster size with winter severity or winter duration. CONCLUSIONS Abundance of hibernating bats is increasing in Central Europe. As the number of M. myotis bats increases, thermally unstable corridors become saturated with large clusters and the animals begin to roost deeper underground.
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Affiliation(s)
- Natália Martínková
- Institute of Vertebrate Biology, Czech Academy of Sciences, Květná 8, Brno, 60365 Czechia
- RECETOX, Masaryk University, Kamenice 753/5, Brno, 62500 Czechia
| | - Stuart J. E. Baird
- Institute of Vertebrate Biology, Czech Academy of Sciences, Květná 8, Brno, 60365 Czechia
| | | | - Jan Zima
- Institute of Vertebrate Biology, Czech Academy of Sciences, Květná 8, Brno, 60365 Czechia
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Stevens RD, Garcia CJ, Madden MA, Gregory BB, Perry RW. Seasonal Changes in the Active Bat Community of the Kisatchie National Forest, Louisiana. SOUTHEAST NAT 2020. [DOI: 10.1656/058.019.0308] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Richard D. Stevens
- Department of Natural Resources Management, Texas Tech University, Lubbock, TX 79409
| | - Carlos J. Garcia
- Department of Natural Resources Management, Texas Tech University, Lubbock, TX 79409
| | - Macy A. Madden
- Department of Biological Sciences, Texas Tech University, Lubbock, TX 79409
| | - Beau B. Gregory
- Louisiana Natural Heritage Program, Louisiana Department of Wildlife and Fisheries, 1213 N. Lakeshore Drive, Lake Charles, LA 70601
| | - Roger W. Perry
- Southern Research Station, United States Forest Service, PO Box 1270, Hot Springs, AR 71902
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35
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Geiser F, Willis CKR, Brigham RM. No evidence for hibernation in rockwrens. J Exp Biol 2020; 223:jeb229518. [PMID: 32788270 DOI: 10.1242/jeb.229518] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 06/04/2020] [Indexed: 11/20/2022]
Affiliation(s)
- Fritz Geiser
- Centre for Behavioural and Physiological Ecology, Zoology CO2, University of New England, Armidale, NSW 2351, Australia
| | - Craig K R Willis
- Department of Biology and Centre for Forest Interdisciplinary Research, University of Winnipeg, Winnipeg, Canada, MB R3B 2E9
| | - R Mark Brigham
- Department of Biology, University of Regina, Regina, Canada, SK S4S 0A2
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36
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Sun H, Wang J, Xing Y, Pan YH, Mao X. Gut transcriptomic changes during hibernation in the greater horseshoe bat ( Rhinolophus ferrumequinum). Front Zool 2020; 17:21. [PMID: 32690984 PMCID: PMC7366455 DOI: 10.1186/s12983-020-00366-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 07/10/2020] [Indexed: 11/10/2022] Open
Abstract
Background The gut is the major organ for nutrient absorption and immune response in the body of animals. Although effects of fasting on the gut functions have been extensively studied in model animals (e.g. mice), little is known about the response of the gut to fasting in a natural condition (e.g. hibernation). During hibernation, animals endure the long term of fasting and hypothermia. Results Here we generated the first gut transcriptome in a wild hibernating bat (Rhinolophus ferrumequinum). We identified 1614 differentially expressed genes (DEGs) during four physiological states (Torpor, Arousal, Winter Active and Summer Active). Gene co-expression network analysis assigns 926 DEGs into six modules associated with Torpor and Arousal. Our results reveal that in response to the stress of luminal nutrient deficiency during hibernation, the gut helps to reduce food intake by overexpressing genes (e.g. CCK and GPR17) that regulate the sensitivity to insulin and leptin. At the same time, the gut contributes energy supply by overexpressing genes that increase capacity for ketogenesis (HMGCS2) and selective autophagy (TEX264). Furthermore, we identified separate sets of multiple DEGs upregulated in Torpor and Arousal whose functions are involved in innate immunity. Conclusion This is the first gut transcriptome of a hibernating mammal. Our study identified candidate genes associated with regulation of food intake and enhance of innate immunity in the gut during hibernation. By comparing with previous studies, we found that two DEGs (CPE and HSPA8) were also significantly elevated during torpor in liver and brain of R. ferrumequinum and several DEGs (e.g. TXNIP and PDK1/4) were commonly upregulated during torpor in multiple tissues of different mammals. Our results support that shared expression changes may underlie the hibernation phenotype by most mammals.
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Affiliation(s)
- Haijian Sun
- School of Ecological and Environmental Sciences, East China Normal University, Shanghai, 200062 China
| | - Jiaying Wang
- Institute of Estuarine and Coastal Research, East China Normal University, Shanghai, 200062 China
| | - Yutong Xing
- Institute of Estuarine and Coastal Research, East China Normal University, Shanghai, 200062 China
| | - Yi-Hsuan Pan
- Key Laboratory of Brain Functional Genomics of Ministry of Education, School of Life Science, East China Normal University, Shanghai, 200062 China
| | - Xiuguang Mao
- School of Ecological and Environmental Sciences, East China Normal University, Shanghai, 200062 China.,Institute of Eco-Chongming (IEC), East China Normal University, Shanghai, 200062 China
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Ferris C, Wright R, Brockhurst MA, Best A. The evolution of host resistance and parasite infectivity is highest in seasonal resource environments that oscillate at intermediate amplitudes. Proc Biol Sci 2020; 287:20200787. [PMID: 32453992 PMCID: PMC7287369 DOI: 10.1098/rspb.2020.0787] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Accepted: 05/01/2020] [Indexed: 12/31/2022] Open
Abstract
Seasonal environments vary in their amplitude of oscillation but the effects of this temporal heterogeneity for host-parasite coevolution are poorly understood. Here, we combined mathematical modelling and experimental evolution of a coevolving bacteria-phage interaction to show that the intensity of host-parasite coevolution peaked in environments that oscillate in their resource supply with intermediate amplitude. Our experimentally parameterized mathematical model explains that this pattern is primarily driven by the ecological effects of resource oscillations on host growth rates. Our findings suggest that in host-parasite systems where the host's but not the parasite's population growth dynamics are subject to seasonal forcing, the intensity of coevolution will peak at intermediate amplitudes but be constrained at extreme amplitudes of environmental oscillation.
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Affiliation(s)
- Charlotte Ferris
- School of Mathematics and Statistics, University of Sheffield, Hicks Building, 226 Hounsfield Road, Sheffield S3 7RH, UK
| | - Rosanna Wright
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, UK
| | - Michael A. Brockhurst
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, UK
| | - Alex Best
- School of Mathematics and Statistics, University of Sheffield, Hicks Building, 226 Hounsfield Road, Sheffield S3 7RH, UK
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38
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Geiser F. Seasonal Expression of Avian and Mammalian Daily Torpor and Hibernation: Not a Simple Summer-Winter Affair †. Front Physiol 2020; 11:436. [PMID: 32508673 PMCID: PMC7251182 DOI: 10.3389/fphys.2020.00436] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Accepted: 04/08/2020] [Indexed: 12/17/2022] Open
Abstract
Daily torpor and hibernation (multiday torpor) are the most efficient means for energy conservation in endothermic birds and mammals and are used by many small species to deal with a number of challenges. These include seasonal adverse environmental conditions and low food/water availability, periods of high energetic demands, but also reduced foraging options because of high predation pressure. Because such challenges differ among regions, habitats and food consumed by animals, the seasonal expression of torpor also varies, but the seasonality of torpor is often not as clear-cut as is commonly assumed and differs between hibernators and daily heterotherms expressing daily torpor exclusively. Hibernation is found in mammals from all three subclasses from the arctic to the tropics, but is known for only one bird. Several hibernators can hibernate for an entire year or express torpor throughout the year (8% of species) and more hibernate from late summer to spring (14%). The most typical hibernation season is the cold season from fall to spring (48%), whereas hibernation is rarely restricted to winter (6%). In hibernators, torpor expression changes significantly with season, with strong seasonality mainly found in the sciurid and cricetid rodents, but seasonality is less pronounced in the marsupials, bats and dormice. Daily torpor is diverse in both mammals and birds, typically is not as seasonal as hibernation and torpor expression does not change significantly with season. Torpor in spring/summer has several selective advantages including: energy and water conservation, facilitation of reproduction or growth during development with limited resources, or minimisation of foraging and thus exposure to predators. When torpor is expressed in spring/summer it is usually not as deep and long as in winter, because of higher ambient temperatures, but also due to seasonal functional plasticity. Unlike many other species, subtropical nectarivorous blossom-bats and desert spiny mice use more frequent and pronounced torpor in summer than in winter, which is related to seasonal availability of nectar or water. Thus, seasonal use of torpor is complex and differs among species and habitats.
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Affiliation(s)
- Fritz Geiser
- Centre for Behavioural and Physiological Ecology, Zoology CO2, University of New England, Armidale, NSW, Australia
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Gottfried I, Gottfried T, Lesiński G, Hebda G, Ignaczak M, Wojtaszyn G, Jurczyszyn M, Fuszara M, Fuszara E, Grzywiński W, Błachowski G, Hejduk J, Jaros R, Kowalski M. Long-term changes in winter abundance of the barbastelle Barbastella barbastellus in Poland and the climate change - Are current monitoring schemes still reliable for cryophilic bat species? PLoS One 2020; 15:e0227912. [PMID: 32069315 PMCID: PMC7028302 DOI: 10.1371/journal.pone.0227912] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 01/02/2020] [Indexed: 11/19/2022] Open
Abstract
Warmer winters may lead to changes in the hibernation behaviour of bats, such as
the barbastelle Barbastella barbastellus, which prefers to
hibernate at low temperatures. The species is also known for its large annual
fluctuations in the number of wintering individuals, so inference about
population trends should be based on long-term data. Prior to 2005, analyses
indicated stable or even increasing barbastelle population in Poland. We
analysed the results of 13 winter bat counts (2005–2017) of the species from 15
of the largest hibernacula, and additional site of 47 small bunkers, in Poland.
The total number of wintering individuals remained stable during the study
period, because the barbastelle is not a long-distance migrant, this likely
reflects the national population trend. On the basis of mean winter air
temperatures we divided the country into four thermal regions. Analyses of
barbastelle abundance in hibernacula in the four regions revealed a 4.8% annual
mean increase in numbers in the coldest region, where mean winter temperatures
were below -2°C, annual mean declines of 3.3% and 3.1% in two warmer regions of
western Poland, but no trend in the region of intermediate mean winter
temperatures of between -1°C and -2°C. Overall, there was a significant, but
weak, negative correlation between the abundance of hibernating individuals and
the mean winter temperature. On the other hand, the number of individuals
hibernating in small bunkers increased, even though the site was located in one
of the warm regions. The results indicate a warming climate will likely reduce
the use of large, well-insulated winter roosts by species that prefer colder
conditions–and that this is already happening. For forest-dwelling bats, such as
the barbastelle, for which monitoring schemes are primarily based on winter
surveys of large hibernacula, estimations of population trends may consequently
become less reliable.
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Affiliation(s)
- Iwona Gottfried
- Department of Behavioural Ecology, University of Wroclaw, Wroclaw,
Poland
- * E-mail:
| | - Tomasz Gottfried
- Polish Society of Wildlife Friends “pro Natura”, Wroclaw,
Poland
| | - Grzegorz Lesiński
- Institute of Animal Sciences, Warsaw University of Life Sciences, Warsaw,
Poland
| | - Grzegorz Hebda
- Institute of Biology, University of Opole, Opole,
Poland
| | | | | | - Mirosław Jurczyszyn
- Department of Systematic Zoology, Adam Mickiewicz University in Poznan,
Poznan, Poland
| | - Maciej Fuszara
- Faculty of Biological Sciences, Cardinal Stefan Wyszynski University in
Warsaw, Warsaw, Poland
| | - Elżbieta Fuszara
- Department of Animal Physiology, University of Warsaw, Warszawa,
Poland
| | - Witold Grzywiński
- Faculty of Forestry, Poznan University of Life Sciences, Poznan,
Poland
| | | | - Janusz Hejduk
- Department of Biodiversity Studies, Teacher Training and Bioeducation,
University of Lodz, Lodz, Poland
| | - Radosław Jaros
- Polish Society for Nature Conservation "SALAMANDRA", Poznan,
Poland
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Doty AC, Gonsalves L, Law BS. Activity patterns of insectivorous bats during a seasonal transition period from hibernation to reproduction. AUSTRALIAN MAMMALOGY 2020. [DOI: 10.1071/am18035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Bat activity is influenced by fluctuating environmental variables. It may also be influenced by energetic pressures related to pregnancy, lactation, and emergence following winter inactivity. We evaluated nightly changes in relative bat activity at Royal National Park in response to Julian date, ambient temperature, precipitation, wind speed and moon phase on a nightly scale for six weeks during spring, as insectivorous bats move out of hibernation or frequent, prolonged torpor, and into the maternal season. Interestingly, later Julian date (reflecting seasonal transition) was the sole variable that best predicted total nightly activity. In addition, we opportunistically assessed bat activity in response to a severe storm, considered a Category 1 cyclone, resulting in 96.4mm of rain in one night and wind speeds up to 94km h–1. Only one species of bat, Chalinolobus gouldii, was active during the storm, with activity restricted to the latter part of the evening when precipitation had reduced, indicating rapid resumption of activity following severe weather. The results of this research can be used as an indicator of emergence from winter inactivity and highlight activity patterns of bat species in relation to environmental variables to inform timing of monitoring programs, bat surveys, and targeted research.
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Affiliation(s)
- Justin G. Boyles
- Cooperative Wildlife Research Laboratory Center for Ecology, and School of Biological Sciences Southern Illinois University Carbondale IL USA
| | | | - Anna Blomberg
- Department of Biology University of Turku Vesilinnantie 520100Turku Finland
| | - Thomas M. Lilley
- Finnish Museum of Natural History University of Helsinki P. Rautatiekatu 1300100Helsinki Finland
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Appel G, López-Baucells A, Magnusson WE, Bobrowiec PED. Temperature, rainfall, and moonlight intensity effects on activity of tropical insectivorous bats. J Mammal 2019. [DOI: 10.1093/jmammal/gyz140] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Abstract
The extrinsic factors that most influence animal activity are weather and light conditions, which can be assessed at hourly, monthly, and even lunar-cycle timescales. We evaluated the responses of tropical aerial-insectivorous bats to temperature, rainfall, and moonlight intensity within and among nights. Temperature positively affected the activity of two species (Cormura brevirostris and Saccopteryx bilineata). Moonlight reduced Myotis riparius activity and increased the activity of Pteronotus rubiginosus and S. leptura. Rainfall can promote an irregular activity peak during the night compared to nights without rainfall, but the bats in our study were not active for a longer time after a rainfall event. Our findings indicate that moonlight and temperature are the variables with the highest impact on the activity of tropical insectivorous bat species and that some species are sensitive to small variations in rainfall among and within nights.
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Affiliation(s)
- Giulliana Appel
- Instituto Nacional de Pesquisas da Amazônia, Programa de Pós-graduação em Ecologia, Manaus, Brazil
| | - Adrià López-Baucells
- Center for Ecology, Evolution and Environmental Changes, University of Lisbon, Campo Grande, Portugal
- Granollers Museum of Natural Sciences, c/Palaudàries, Granollers, Spain
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43
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Patriquin KJ, Guy C, Hinds J, Ratcliffe JM. Male and female bats differ in their use of a large urban park. JOURNAL OF URBAN ECOLOGY 2019. [DOI: 10.1093/jue/juz015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Understanding how wildlife respond to ever-encroaching urbanization is of great concern. Bats are the second-most speciose mammalian order and while many appear to be urban adapted, we currently have a limited understanding of their demography and habitat use within urban environments. Using a combination of captures to obtain demographic data, radio-telemetry to examine foraging and roosting behaviour, and data on diet and prey availability, we examined how big brown bats (Eptesicus fuscus), a synurbic species, use an urban green space (High Park) in Canada’s largest city centre, Toronto. We found that adult males outnumbered adult females more than two to one and that males were found throughout the park, while females were concentrated in an area with greater access to water, but lower prey availability. We also found that bats of both sexes were in poorer body condition than reported for other non-urban areas, including a site within southern Ontario. Our data suggest that High Park may not provide adequate resources for reproductive females as they were never found roosting in the park and beetles, their preferred prey, were limited. Although previous studies suggest urban green spaces may offer refuge to bats, most have not considered sex-specific responses to urbanization as they have largely been based on acoustic surveys. Our study therefore highlights the importance of considering demographic differences in response to urbanization to better inform urban management plans and green space development.
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Affiliation(s)
- Krista J Patriquin
- Department of Biology, University of Toronto Mississauga, 3359 Mississauga Road, William G Davis Building, Mississauga, Ontario L5L 1C6, Canada
| | - Cylita Guy
- Department of Biology, University of Toronto Mississauga, 3359 Mississauga Road, William G Davis Building, Mississauga, Ontario L5L 1C6, Canada
| | - Joshua Hinds
- Department of Biology, University of Toronto Mississauga, 3359 Mississauga Road, William G Davis Building, Mississauga, Ontario L5L 1C6, Canada
| | - John M Ratcliffe
- Department of Biology, University of Toronto Mississauga, 3359 Mississauga Road, William G Davis Building, Mississauga, Ontario L5L 1C6, Canada
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Hanadhita D, Rahma A, Prawira AY, Mayasari NLPI, Satyaningtijas AS, Hondo E, Agungpriyono S. The spleen morphophysiology of fruit bats. Anat Histol Embryol 2019; 48:315-324. [PMID: 30968443 PMCID: PMC7159459 DOI: 10.1111/ahe.12442] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 02/12/2019] [Accepted: 03/16/2019] [Indexed: 11/29/2022]
Abstract
Spleen is one of the important lymphoid organs with wide variations of morphological and physiological functions according to species. Morphology and function of the spleen in bats, which are hosts to several viral strains without exhibiting clinical symptoms, remain to be fully elucidated. This study aims to examine the spleen morphology of fruit bats associated with their physiological functions. Spleen histological observations were performed in three fruit bats species: Cynopterus titthaecheilus (n = 9), Rousettus leschenaultii (n = 3) and Pteropus vampyrus (n = 3). The spleens of these fruit bats were surrounded by a thin capsule. Red pulp consisted of splenic cord and wide vascular space filled with blood. Ellipsoids in all three studied species were found numerously and adjacent to one another forming macrophages aggregates. White pulp consisted of periarteriolar lymphoid sheaths (PALS), lymphoid follicles and marginal zone. The lymphoid follicle contained a germinal centre and a tingible body macrophage that might reflect an active immune system. The marginal zone was prominent and well developed. This study reports some differences in spleen structure of fruit bats compared to other bat species previously reported and discusses possible physiological implications of the spleen based on its morphology.
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Affiliation(s)
- Desrayni Hanadhita
- Department of Anatomy Physiology and Pharmacology, Faculty of Veterinary MedicineBogor Agricultural University (IPB)BogorIndonesia
| | - Anisa Rahma
- Department of Anatomy Physiology and Pharmacology, Faculty of Veterinary MedicineBogor Agricultural University (IPB)BogorIndonesia
| | - Andhika Yudha Prawira
- Department of Anatomy Physiology and Pharmacology, Faculty of Veterinary MedicineBogor Agricultural University (IPB)BogorIndonesia
| | - Ni Luh Putu Ika Mayasari
- Department of Animal Disease and Veterinary Public Health, Faculty of Veterinary MedicineBogor Agricultural University (IPB)BogorIndonesia
| | - Aryani Sismin Satyaningtijas
- Department of Anatomy Physiology and Pharmacology, Faculty of Veterinary MedicineBogor Agricultural University (IPB)BogorIndonesia
| | - Eiichi Hondo
- Laboratory of Animal Morphology, Graduate School of Bioagricultural SciencesNagoya UniversityNagoyaJapan
| | - Srihadi Agungpriyono
- Department of Anatomy Physiology and Pharmacology, Faculty of Veterinary MedicineBogor Agricultural University (IPB)BogorIndonesia
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Abstract
Cimicid insects, bed bugs and their allies, include about 100 species of blood-feeding ectoparasites. Among them, a few have become widespread and abundant pests of humans. Cimicids vary in their degree of specialization to hosts. Whereas most species specialize on insectivorous birds or bats, the common bed bug can feed on a range of distantly related host species, such as bats, humans, and chickens. We suggest that association with humans and generalism in bed bugs led to fundamentally different living conditions that fostered rapid growth and expansion of their populations. We propose that the evolutionary and ecological success of common bed bugs reflected exploitation of large homeothermic hosts (humans) that sheltered in buildings. This was a departure from congeners whose hosts are much smaller and often heterothermic. We argue that interesting insights into the biology of pest species may be obtained using an integrated view of their ecology and evolution.
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Affiliation(s)
- Benoit Talbot
- School of Epidemiology and Public Health, University of Ottawa, Ottawa, ON K1G 5Z3, Canada
| | - Nusha Keyghobadi
- Department of Biology, University of Western Ontario, London, ON N6A 5B7, Canada
| | - Brock Fenton
- Department of Biology, University of Western Ontario, London, ON N6A 5B7, Canada
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Variation in Summer and Winter Microclimate in Multi-Chambered Bat Boxes in Eastern Australia: Potential Eco-Physiological Implications for Bats. ENVIRONMENTS 2019. [DOI: 10.3390/environments6020013] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Bat boxes are commonly used as a conservation tool. Detailed knowledge on the influence of box elements on microclimate is lacking, despite eco-physiological implications for bats. Summer and winter box temperature and relative humidity patterns were studied in narrow multi-chambered plywood and wood-cement boxes in eastern Australia. Box exteriors were black or white and plywood boxes comprised vents. Relative humidity was higher in white boxes than black boxes and box colour, construction material, chamber sequence and vents influenced temperatures. Maximum box temperature differences between designs varied by up to 9.0 °C in summer and 8.5 °C in winter. The black plywood box consistently recorded the warmest temperatures. This design comprised a temperature gradient between chambers and within the front chamber (influenced by vent). During the 32-day summer sampling period, the front chamber rarely recorded temperatures over 40.0 °C (postulated upper thermal tolerance limit of bats), while the third and fourth chamber never reached this threshold. At the study site, the tested black boxes are considered most thermally suitable for bats during average summer conditions. However, during temperature extremes black boxes likely become too hot. Wood-cement, a durable material not previously tested in Australia should be considered as an alternative construction material.
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Geiser F, Bondarenco A, Currie SE, Doty AC, Körtner G, Law BS, Pavey CR, Riek A, Stawski C, Turbill C, Willis CKR, Brigham RM. Hibernation and daily torpor in Australian and New Zealand bats: does the climate zone matter? AUST J ZOOL 2019. [DOI: 10.1071/zo20025] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
We aim to summarise what is known about torpor use and patterns in Australian and New Zealand (ANZ) bats from temperate, tropical/subtropical and arid/semiarid regions and to identify whether and how they differ. ANZ bats comprise ~90 species from 10 families. Members of at least nine of these are known to use torpor, but detailed knowledge is currently restricted to the pteropodids, molossids, mystacinids, and vespertilionids. In temperate areas, several species can hibernate (use a sequence of multiday torpor bouts) in trees or caves mostly during winter and continue to use short bouts of torpor for the rest of the year, including while reproducing. Subtropical vespertilionids also use multiday torpor in winter and brief bouts of torpor in summer, which permit a reduction in foraging, probably in part to avoid predators. Like temperate-zone vespertilionids they show little or no seasonal change in thermal energetics during torpor, and observed changes in torpor patterns in the wild appear largely due to temperature effects. In contrast, subtropical blossom-bats (pteropodids) exhibit more pronounced daily torpor in summer than winter related to nectar availability, and this involves a seasonal change in physiology. Even in tropical areas, vespertilionids express short bouts of torpor lasting ~5 h in winter; summer data are not available. In the arid zone, molossids and vespertilionids use torpor throughout the year, including during desert heat waves. Given the same thermal conditions, torpor bouts in desert bats are longer in summer than in winter, probably to minimise water loss. Thus, torpor in ANZ bats is used by members of all or most families over the entire region, its regional and seasonal expression is often not pronounced or as expected, and it plays a key role in energy and water balance and other crucial biological functions that enhance long-term survival by individuals.
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48
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Turbill C, Körtner G, Geiser F. Roost use and thermoregulation by female Australian long-eared bats (Nyctophilus geoffroyi and N. gouldi) during pregnancy and lactation. AUST J ZOOL 2019. [DOI: 10.1071/zo20036] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Small insectivorous bats commonly use torpor while day-roosting, even in summer. However, reproductive female bats are believed to benefit from avoiding torpor because a constant, elevated body temperature maximises the rate of offspring growth, which could increase offspring survival. We used temperature-sensitive radio-transmitters to locate roosts and document the thermal biology of pregnant and lactating females of Nyctophilus geoffroyi (9 g) and N. gouldi (11 g) at a woodland in a cool temperate climate. Unlike males, reproductive female Nyctophilus spp. roosted as small groups (<25) within insulated tree cavities. Roost switching occurred every 3.7 ± 1.5 (N. geoffroyi) or 1.7 ± 0.8 days (N. gouldi), and radio-tagged individuals roosted together and apart on different days. Skin temperature during roosting was most often between 32 and 36°C, and torpor was used infrequently. Male Nyctophilus have been shown in previous studies to use torpor daily during summer. These contrasting torpor patterns likely reflect the warmed cavities occupied by maternity colonies and the thermally unstable shallow crevices occupied by individual males. Our results support the hypothesis that availability of thermally suitable roosts will influence thermoregulatory patterns of reproductive females and hence the growth rates and survival of their offspring. Thus, it is important to conserve woodland habitat with trees in a range of decay stages to provide opportunities for selection and movement among roost trees by reproductive female bats.
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49
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Garin I, Chaverri G, Jimenez L, Castillo-Salazar C, Aihartza J. Contrasting thermal strategies of montane Neotropical bats at high elevations. J Therm Biol 2018; 78:352-355. [PMID: 30509657 DOI: 10.1016/j.jtherbio.2018.10.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 10/17/2018] [Accepted: 10/18/2018] [Indexed: 10/28/2022]
Abstract
In the Neotropics, captive vespertilionid bats substantially reduce their metabolic rate at low ambient temperatures, similar to their temperate counterparts, whereas the ability of phyllostomids to lower metabolic rate seems to be more limited, even in mountain species. Nevertheless, field data on the thermal behaviour of syntopic individuals from these two families is lacking. Consequently, we aimed to test whether torpor was more common and deeper in vesper bats compared to leaf-nosed bats by studying skin temperature (Tsk) variation in individuals experiencing the same environmental conditions at a mountain area. Bats experienced ambient temperatures below 15 °C. Average Tsk was 10 °C in Myotis oxyotus gardneri (Vespertilionidae) during the day, while Sturnira burtonlimi (Phyllostomidae) regulated diurnal Tsk above 30 °C. Constant food availability may explain why diurnal Sturnira burtonlimi pay the high energetic cost required to remain normothermic and to defend a wide Ta-Tsk gap but further studies are needed to elucidate additional strategies that may be employed by these bats to reduce the energetic demands of normothermy. Our study shows that the contrasting thermal strategies and torpor use adopted by vespertilionid insectivores and phyllostomid frugivores in captive settings also occur in free-ranging conditions, thus providing a basis to develop further studies with predictions more accurately rooted in field data.
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Affiliation(s)
- I Garin
- Zoology and Animal Cell Biology, University of The Basque Country UPV/EHU, Sarriena z/g, 48940 Leioa, The Basque Country.
| | - G Chaverri
- Recinto de Golfito, Universidad de Costa Rica, Golfito, Costa Rica
| | - L Jimenez
- Zoology and Animal Cell Biology, University of The Basque Country UPV/EHU, Sarriena z/g, 48940 Leioa, The Basque Country
| | | | - J Aihartza
- Zoology and Animal Cell Biology, University of The Basque Country UPV/EHU, Sarriena z/g, 48940 Leioa, The Basque Country
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50
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Lazzeroni ME, Burbrink FT, Simmons NB. Hibernation in bats (Mammalia: Chiroptera) did not evolve through positive selection of leptin. Ecol Evol 2018; 8:12576-12596. [PMID: 30619566 PMCID: PMC6308895 DOI: 10.1002/ece3.4674] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Revised: 09/10/2018] [Accepted: 09/14/2018] [Indexed: 01/25/2023] Open
Abstract
Temperature regulation is an indispensable physiological activity critical for animal survival. However, relatively little is known about the origin of thermoregulatory regimes in a phylogenetic context, or the genetic mechanisms driving the evolution of these regimes. Using bats as a study system, we examined the evolution of three thermoregulatory regimes (hibernation, daily heterothermy, and homeothermy) in relation to the evolution of leptin, a protein implicated in regulation of torpor bouts in mammals, including bats. A threshold model was used to test for a correlation between lineages with positively selected lep, the gene encoding leptin, and the thermoregulatory regimes of those lineages. Although evidence for episodic positive selection of lep was found, positive selection was not correlated with lineages of heterothermic bats, a finding that contradicts results from previous studies. Evidence from our ancestral state reconstructions suggests that the most recent common ancestor of bats used daily heterothermy and that the presence of hibernation is highly unlikely at this node. Hibernation likely evolved independently at least four times in bats-once in the common ancestor of Vespertilionidae and Molossidae, once in the clade containing Rhinolophidae and Rhinopomatidae, and again independently in the lineages leading to Taphozous melanopogon and Mystacina tuberculata. Our reconstructions revealed that thermoregulatory regimes never transitioned directly from hibernation to homeothermy, or the reverse, in the evolutionary history of bats. This, in addition to recent evidence that heterothermy is best described along a continuum, suggests that thermoregulatory regimes in mammals are best represented as an ordered continuous trait (homeothermy ← → daily torpor ← → hibernation) rather than as the three discrete regimes that evolve in an unordered fashion. These results have important implications for methodological approaches in future physiological and evolutionary research.
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Affiliation(s)
| | - Frank T. Burbrink
- Division of Vertebrate Zoology, Department of HerpetologyAmerican Museum of Natural HistoryNew YorkNew York
| | - Nancy B. Simmons
- Division of Vertebrate Zoology, Department of MammalogyAmerican Museum of Natural HistoryNew YorkNew York
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