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Lopez-Idiaquez D, Teplitsky C, Grégoire A, Fargevieille A, Rey MD, Franceschi CD, Charmantier A, Doutrelant C. Long-term decrease in coloration: a consequence of climate change? Am Nat 2022; 200:32-47. [DOI: 10.1086/719655] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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2
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Hund AK, Hubbard JK, Krausová S, Munclinger P, Safran RJ. Different underlying mechanisms drive associations between multiple parasites and the same sexual signal. Anim Behav 2021. [DOI: 10.1016/j.anbehav.2020.12.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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3
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The dark ventral patch: A bimodal flexible trait related to male competition in red deer. PLoS One 2020; 15:e0241374. [PMID: 33151970 PMCID: PMC7644014 DOI: 10.1371/journal.pone.0241374] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Accepted: 10/13/2020] [Indexed: 11/29/2022] Open
Abstract
Sexual signals play a central role in male-male competition in polygynous species. In red deer (Cervus elaphus), male’s ventral area become dark during the rutting season due to urine spraying behaviour and retains many chemical compounds potentially revealing individual features. Here we investigate the variation in size of this trait, exploring its relationship with age and male competitive features such as antlers or body size, as well as populational level of intrasexual competition for mates. We found that the size of the dark ventral patch followed a clearly bimodal distribution, i.e. males mostly expressed the full-size trait or just developed a very small one. For these two groups of males according to trait expression, the relationships of trait size with age and antler size differed. Populational level of intrasexual competition appeared to affect the relationship between antler size and the probability of a fully developed ventral patch. These results indicate that the trait encodes information on body size, antler size, age and populational level of mate competition, thus suggesting a role in signalling male’s competitive features and willingness to allocate reproductive effort within a particular season.
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4
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Ziegelbecker A, Remele K, Pfeifhofer HW, Sefc KM. Wasteful carotenoid coloration and its effects on territorial behavior in a cichlid fish. HYDROBIOLOGIA 2020; 848:3683-3698. [PMID: 34720169 PMCID: PMC8549929 DOI: 10.1007/s10750-020-04354-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 06/30/2020] [Accepted: 07/08/2020] [Indexed: 06/13/2023]
Abstract
The famously diverse body coloration of cichlid fish serves communicative functions in mating and social interactions including competition for resources. Here, we examined the effects of a color pattern trait-the width of a yellow bar on a black body-on territorial competition in males and females of a color variant ("Ikola") of the Lake Tanganyika cichlid Tropheus. First, measuring integumentary carotenoid concentrations in the yellow and black body regions, we established that wider yellow bars require more carotenoids allocated to body coloration. However, we also detected high carotenoid concentrations in the black body regions (> 100 µg/g fresh skin), raising questions about the function of non-displayed integumentary carotenoids. Behavioral experiments showed that fish with wider bars were quicker to explore an unfamiliar area of the tank. In experiments including presentations of fish dummies, the bar width of 'territorial' dummies had no effect on the latency time which test fish took to intrude into the dummies' territories. However, male test fish performed fewer aggressive acts against wide-barred than against narrow-barred dummy competitors. Our results suggest that intimidation by wide bars as well as correlations between bar width and explorative behavior may contribute to mediating success in territorial Tropheus "Ikola".
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Affiliation(s)
| | - Klaus Remele
- Institute of Biology, University of Graz, Schubertstraße 51, 8010 Graz, Austria
| | | | - Kristina M. Sefc
- Institute of Biology, University of Graz, Universitätsplatz 2, 8010 Graz, Austria
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5
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Leary CJ, Baugh AT. Glucocorticoids, male sexual signals, and mate choice by females: Implications for sexual selection. Gen Comp Endocrinol 2020; 288:113354. [PMID: 31830474 DOI: 10.1016/j.ygcen.2019.113354] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 12/01/2019] [Accepted: 12/06/2019] [Indexed: 12/29/2022]
Abstract
We review work relating glucocorticoids (GCs), male sexual signals, and mate choice by females to understand the potential for GCs to modulate the expression of sexually selected traits and how sexual selection potentially feeds back on GC regulation. Our review reveals that the relationship between GC concentrations and the quality of male sexual traits is mixed, regardless of whether studies focused on structural traits (e.g., coloration) or behavioral traits (e.g., vocalizations) or were examined in developmental or activational frameworks. In contrast, the few mate choice experiments that have been done consistently show that females prefer males with low GCs, suggesting that mate choice by females favors males that maintain low levels of GCs. We point out, however, that just as sexual selection can drive the evolution of diverse reproductive strategies, it may also promote diversity in GC regulation. We then shift the focus to females where we highlight evidence indicating that stressors or high GCs can dampen female sexual proceptivity and the strength of preferences for male courtship signals. Hence, even in cases where GCs are tightly coupled with male sexual signals, the strength of sexual selection on aspects of GC physiology can vary depending on the endocrine status of females. Studies examining how GCs relate to sexual selection may shed light on how variation in stress physiology, sexual signals, and mate choice are maintained in natural populations and may be important in understanding context-dependent relationships between GC regulation and fitness.
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Affiliation(s)
- Christopher J Leary
- Department of Biology, University of Mississippi, PO Box 1848, University, MS 38677, USA.
| | - Alexander T Baugh
- Department of Biology, Swarthmore College, 500 College Avenue, Swarthmore, PA 19081, USA
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6
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Assessment of Cortisol and DHEA Concentrations in Griffon Vulture ( Gyps fulvus) Feathers to Evaluate its Allostatic Load. ANNALS OF ANIMAL SCIENCE 2020. [DOI: 10.2478/aoas-2019-0051] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Abstract
The use of a non-invasive approach to collect biological samples from natural populations represents a great means of gathering information while avoiding handling animals. Even if corticosterone is the main glucocorticoid investigated in birds, there has been observed a proportional direct link between corticosterone and cortisol concentrations. Dehydroepiandrosterone (DHEA) can be produced by the adrenal cortex and should have prominent antiglucocorticoid properties also in birds. The aim of this study was to verify if there is any difference in the cortisol and DHEA feather concentrations between clinically normal and physiologically compromised Griffon vultures (Gyps fulvus) through the non-invasive approach of collecting moulted feathers without having to pluck them from the bird. The study was carried out using 8 physiologically compromised (PC) Griffons and 9 clinically normal Griffons considered as the control (CTRL) group that were necropsied or from the wildlife rehabilitation centre. Primary and secondary covert feathers were either collected directly from the birds’ cage floors, or, in the case of dead Griffons, they were plucked off the animals. The results, obtained by RIA, revealed that both cortisol (P<0.01) and DHEA (P<0.05) feather concentrations were higher in the PC than in the CTRL group. No difference was observed by comparing the cortisol/DHEA ratio between the two evaluated groups (P=0.15). Pearson’s correlation coefficients showed no correlation between feather hormone concentrations in the PC group (r=0.01, P=0.96) while a positive correlation in the CTRL group (r=0.65, P=0.006) was observed. In conclusion, our study reveals that moulted feathers can be a non-invasive and an interesting tool to evaluate the allostatic load of wild birds and they allowed better understanding the relationship between hormones of the hypothalamic–pituitary–adrenal axis and the physiological status of the birds.
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7
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Gould GM, Carter GG, Augustine JK. Divergent color signals from homologous unfeathered ornaments in two congeneric grouse. Ecol Evol 2019; 9:11833-11847. [PMID: 31695891 PMCID: PMC6822034 DOI: 10.1002/ece3.5687] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2019] [Revised: 08/30/2019] [Accepted: 09/05/2019] [Indexed: 11/16/2022] Open
Abstract
Color-based visual signals are important aspects of communication throughout the animal kingdom. Individuals evaluate color to obtain information about age and condition and to behave accordingly. Birds display a variety of striking, conspicuous colors and make ideal subjects for the study of color signaling. While most studies of avian color focus on plumage, bare unfeathered body parts also display a wide range of color signals. Mate choice and intrasexual competitive interactions are easily observed in lekking grouse, which also signal with prominent unfeathered color patches. Most male grouse have one pair of colorful bare part ornaments (combs), and males of several species also have inflatable air sacs in their throat. Previous studies have mostly focused on comb color and size, but little is known about the signaling role of air sac color. We measured comb size and the color properties of combs and air sacs in the Lesser and Greater Prairie-Chickens (Tympanuchus pallidicinctus and T. cupido, respectively), and investigated whether these properties varied with age and mass. We found that mass predicted color properties of air sacs and that age predicted comb size in the Greater Prairie-Chicken, suggesting that these ornaments indicate condition dependence. No conclusive relationships between color and age or size were detected in the Lesser Prairie-Chicken. Color properties of both ornaments differed between the two species. Further research is needed to determine mechanisms that link condition to color and whether the information advertised by color signals from these ornaments is intended for males, females, or both.
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Affiliation(s)
- Geoffrey M. Gould
- Department of Evolution, Ecology and Organismal BiologyThe Ohio State UniversityColumbusOHUSA
| | - Gerald G. Carter
- Department of Evolution, Ecology and Organismal BiologyThe Ohio State UniversityColumbusOHUSA
| | - Jacqueline K. Augustine
- Department of Evolution, Ecology and Organismal BiologyThe Ohio State University at LimaLimaOHUSA
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8
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Berg ML, Knott B, Ribot RFH, Buchanan KL, Bennett ATD. Do glucocorticoids or carotenoids mediate plumage coloration in parrots? An experiment in Platycercus elegans. Gen Comp Endocrinol 2019; 280:82-90. [PMID: 31002829 DOI: 10.1016/j.ygcen.2019.04.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 04/10/2019] [Accepted: 04/15/2019] [Indexed: 11/29/2022]
Abstract
Conspicuous coloration can indicate phenotypic quality, and may reflect exposure or vulnerability to stress, or access to essential nutrients such as pigments. Although the production of pigmented colours is well understood, much less is known about how structural colours are affected by physiological state. In this study, we tested whether glucocorticoids (corticosterone) predicted expression of plumage coloration in an Australian parrot, the crimson rosella (Platycercus elegans). Parrots provide an interesting and unique test, as they possess conspicuous coloration produced by distinctive pigments known as psittacofulvins, in addition to structural coloration. We have previously documented that coloration in P. elegans is condition-dependent and responds to dietary manipulation. Here, n = 21 P. elegans underwent a dietary manipulation (including food restriction or carotenoid supplementation) during which they moulted, and the change in reflectance was measured for three structural and three pigmentary plumage patches. Stress-induced corticosterone (10 min after handling) measured at the start of the experiment predicted change in coloration in two pigmentary patches (crown and front). We also found that change in stress-induced corticosterone during the experiment was associated with the change in coloration of the crown and two structural patches (cheek and epaulette). Baseline corticosterone (<3 min after handling) was not associated with any measure of coloration. We found no effects of dietary manipulation on baseline or stress-induced corticosterone, but carotenoid supplementation was associated with an increase in a measure of chronic stress (heterophil/lymphocyte ratio), and the corticosterone response to handling decreased over the course of the study. Our results suggest that corticosterone may be linked to colour expression more broadly than previously recognised, including psittacofulvin and structural coloration in parrots, and they confirm the independence of plumage pigmentation in parrots from carotenoid accumulation. Moreover, our study provides new insight into the stress responses of Psittaciformes, one of the most highly threatened avian orders.
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Affiliation(s)
- Mathew L Berg
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Australia; School of Biological Sciences, University of Bristol, United Kingdom.
| | - Ben Knott
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Australia; School of Biological Sciences, University of Bristol, United Kingdom
| | - Raoul F H Ribot
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Australia; School of Biological Sciences, University of Bristol, United Kingdom
| | - Katherine L Buchanan
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Australia; School of Biosciences, Cardiff University, United Kingdom
| | - Andrew T D Bennett
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Australia; School of Biological Sciences, University of Bristol, United Kingdom
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9
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Gold S, Regan CE, McLoughlin PD, Gilleard JS, Wilson AJ, Poissant J. Quantitative genetics of gastrointestinal strongyle burden and associated body condition in feral horses. INTERNATIONAL JOURNAL FOR PARASITOLOGY-PARASITES AND WILDLIFE 2019; 9:104-111. [PMID: 31011533 PMCID: PMC6462499 DOI: 10.1016/j.ijppaw.2019.03.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Revised: 02/16/2019] [Accepted: 03/10/2019] [Indexed: 12/12/2022]
Abstract
Variability in host resistance or tolerance to parasites is nearly ubiquitous, and is of key significance in understanding the evolutionary processes shaping host-parasite interactions. While ample research has been conducted on the genetics of parasite burden in livestock, relatively little has been done in free-living populations. Here, we investigate the sources of (co)variation in strongyle nematode faecal egg count (FEC) and body condition in Sable Island horses, a feral population in which parasite burden has previously been shown to negatively correlate with body condition. We used the quantitative genetic "animal model" to understand the sources of (co)variation in these traits, and tested for impacts of an important spatial gradient in habitat quality on the parameter estimates. Although FEC is significantly heritable (h 2 = 0.43 ± 0.11), there was no evidence for significant additive genetic variation in body condition (h 2 = 0.04 ± 0.07), and therefore there was also no significant genetic covariance between the two traits. The negative phenotypic covariance between these traits therefore does not derive principally from additive genetic effects. We also found that both FEC and body condition increase from east to west across the island, which indicates that the longitudinal environmental gradient is not responsible for the negative phenotypic association observed between these traits. There was also little evidence to suggest that quantitative genetic parameters were biased when an individual's location along the island's environmental gradient was not incorporated into the analysis. This research provides new and important insights into the genetic basis and adaptive potential of parasite resistance in free-living animals, and highlights the importance of environmental heterogeneity in modulating host-parasite interactions in wild vertebrate systems.
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Affiliation(s)
- Susannah Gold
- College of Life and Environmental Sciences, University of Exeter, Cornwall Campus, Penryn, TR10 9FE, UK
| | - Charlotte E Regan
- Department of Biology, University of Saskatchewan, 112 Science Place, Saskatoon, SK, S7N 5E2, Canada
| | - Philip D McLoughlin
- Department of Biology, University of Saskatchewan, 112 Science Place, Saskatoon, SK, S7N 5E2, Canada
| | - John S Gilleard
- Department of Comparative Biology and Experimental Medicine, University of Calgary, 3280 Hospital Drive, Calgary, AB, T2N 4Z6, Canada
| | - Alastair J Wilson
- College of Life and Environmental Sciences, University of Exeter, Cornwall Campus, Penryn, TR10 9FE, UK
| | - Jocelyn Poissant
- Department of Ecosystem and Public Health, University of Calgary, 3280 Hospital Drive, Calgary, AB, T2N 4Z6, Canada
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10
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Endocrine and immune responses of larval amphibians to trematode exposure. Parasitol Res 2018; 118:275-288. [DOI: 10.1007/s00436-018-6154-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2018] [Accepted: 11/12/2018] [Indexed: 11/26/2022]
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11
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Freeman-Gallant CR, Taff CC. Age and infection history are revealed by different ornaments in a warbler. Oecologia 2018; 188:1025-1036. [PMID: 30291422 DOI: 10.1007/s00442-018-4268-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Accepted: 09/28/2018] [Indexed: 11/30/2022]
Abstract
Female preference for older or more disease-resistant males are both possible outcomes of parasite-mediated sexual selection, but the extent to which infection alters the development of ornaments to yield signals of male age and health has rarely been explored. In a longitudinal study of 61 male common yellowthroats (Geothlypis trichas), age-related increases in the size of the melanin-based mask and carotenoid-based bib were not correlated among young males, likely owing to differences in how blood parasites affect ornament development. Infection with trypanosomes and hemosporidians in a male's first breeding season was associated with slower growth of the mask; uninfected males attained large masks in their second breeding season, while infected males attained large masks in their third breeding season. In contrast, the bib size of males increased every year regardless of infection. As a consequence, different populations of males are identified by the largest ornaments-older males in the case of bib and a combination of older males and young, uninfected males in the case of mask. Although mask is thus the more informative trait with respect to male health, females prefer large bibs in our population. If infection is opportunistic, young, uninfected males may not possess good genes for parasite resistance but simply good luck, and it may benefit females to prefer older males who are more likely to have withstood prior episodes of selection. A "pure" signal of age may be a more reliable signal of resistance to parasites than an ornament whose expression is modulated by infection.
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Affiliation(s)
| | - Conor C Taff
- Laboratory of Ornithology, Department of Ecology & Evolutionary Biology, Cornell University, Ithaca, New York, USA
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12
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Magnhagen C, Backström T, Nilsson J, Brännäs E. Oxygen consumption and swimming performance in Arctic charr with different pigmentation patterns. Appl Anim Behav Sci 2018. [DOI: 10.1016/j.applanim.2018.01.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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13
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Sumasgutner P, Adrion M, Gamauf A. Carotenoid coloration and health status of urban Eurasian kestrels (Falco tinnunculus). PLoS One 2018; 13:e0191956. [PMID: 29420544 PMCID: PMC5805255 DOI: 10.1371/journal.pone.0191956] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Accepted: 01/15/2018] [Indexed: 11/18/2022] Open
Abstract
As the world experiences rapid urban expansion, natural landscapes are being transformed into cities at an alarming rate. Consequently, urbanization is identified as one of the biggest environmental challenges of our time, yet we lack a clear understanding of how urbanization affects free-living organisms. Urbanization leads to habitat fragmentation and increased impervious surfaces affecting for example availability and quality of food. Urbanization is also associated with increased pollution levels that can affect organisms directly, via ecophysiological constraints and indirectly by disrupting trophic interactions in multi-species networks. Birds are highly mobile, while an individual is not necessarily exposed to urban stressors around the clock, but nestlings of altricial birds are. Such a city-dwelling species with a long nestling phase is the Eurasian kestrel (Falco tinnunculus) in Vienna, Austria, which forage on a diverse diet differing in composition from rural habitats. Furthermore, prey items vary in nutritional value and contents of micronutrients like carotenoids, which might impact the nestlings' health. Carotenoids are pigments that are incorporated into integument tissues but also have antioxidant and immunostimulatory capacity, resulting in a trade-off between these functions. In nestlings these pigments function in parent-offspring communication or sibling competition by advertising an individual's physical or physiological condition. Anthropogenic disturbance and pollutants could have disruptive effects on the coloration of these traits. In this study, we measured carotenoid based coloration and other indicators of individual health (body condition and susceptibility to the ectoparasite Carnus hemapterus) of 154 nestling kestrels (n = 91 nests) along an urban gradient from 2010 to 2015. We found skin yellowness of nestlings from nest-sites in the city-center to be least pronounced. This result might indicate that inner-city nestlings are strongly affected by urban stressors and depleted their stores of dietary carotenoids for health-related functions rather than coloration. In addition, skin yellowness intensified with age and was stronger pronounced in earlier nests. Since the immune system of nestlings is still developing, younger chicks might need more antioxidants to combat environmental stress. Additionally, parasite infection intensity was highest in nestlings with less intense skin yellowness (paler or less yellow pigmented integuments) and in earlier nests of the season. In combination with results from previous studies, our findings provide further support for the low quality of the inner-city habitat, both in terms of productivity and individual health.
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Affiliation(s)
- Petra Sumasgutner
- Department of Integrative Zoology, University of Vienna, Vienna, Austria
- Museum of Natural History Vienna, Vienna, Austria
- FitzPatrick Institute of African Ornithology, DST-NRF Centre of Excellence, University of Cape Town, Cape Town, South Africa
- * E-mail:
| | - Marius Adrion
- Department of Integrative Zoology, University of Vienna, Vienna, Austria
- Museum of Natural History Vienna, Vienna, Austria
| | - Anita Gamauf
- Department of Integrative Zoology, University of Vienna, Vienna, Austria
- Museum of Natural History Vienna, Vienna, Austria
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14
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Freeman-Gallant CR, Taff CC. Age-specific patterns of infection with haemosporidians and trypanosomes in a warbler: implications for sexual selection. Oecologia 2017; 184:813-823. [PMID: 28756490 DOI: 10.1007/s00442-017-3919-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Accepted: 07/14/2017] [Indexed: 11/29/2022]
Abstract
Although the selective loss of individuals susceptible to disease can favor the evolution of female preference for older males, the interrelationship between age, infection, longevity, and mating success remains poorly characterized in natural populations. In a longitudinal study of 61 male common yellowthroats (Geothlypis trichas), we found that the probability of infection with hematozoa increased as males aged from 1 to 5 years. Despite a significant, negative association between infection and longevity that partially masked age-effects, the odds that a male was infected with Trypanosoma, Plasmodium, or Leucocytozoon increased 71-212% per year. Nearly 75% of males in their first breeding season were either uninfected or infected with only a single parasite, while 50% of older males were infected with at least two parasites and 16% were infected with all three. No males escaped infection after their second breeding season. Older males were also more likely to sire extra-pair young (EPY) and, as a consequence, infection with multiple parasites was associated with a fourfold increase in the odds of producing EPY. Unlike younger males, 80% of the oldest males had a history of either surviving chronic infection or recovering. Combined with previous work showing higher diversity at the major histocompatibility complex among older males, our results suggest that the song and plumage traits that signal male age in common yellowthroats also, perforce, signal resistance to parasites. By preferring older males, females may obtain good genes for disease resistance even in the absence of any effect of infection on male ornamentation.
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Affiliation(s)
| | - Conor C Taff
- Laboratory of Ornithology, Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, USA
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15
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Aharon-Rotman Y, Buchanan KL, Klaassen M, Buttemer WA. An experimental examination of interindividual variation in feather corticosterone content in the house sparrow, Passer domesticus in southeast Australia. Gen Comp Endocrinol 2017; 244:93-100. [PMID: 26699204 DOI: 10.1016/j.ygcen.2015.12.010] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Revised: 12/08/2015] [Accepted: 12/13/2015] [Indexed: 10/22/2022]
Abstract
Non-invasive techniques for measuring glucocorticoids (GCs) have become more prevalent, due to the advantage of eliminating the effects of animal disturbance on GC levels and their potential to provide an integrated, historic estimate of circulating GC levels. In the case of birds, corticosterone (CORT) is deposited in feathers, and may reflect a bird's GC status over the period of feather synthesis. This technique thus permits a retrospective view of the average circulating GC levels during the moult period. While it is generally assumed that differences in feather CORT content (CORTf) between individuals reflects their different stress histories during either natural or induced moult, it is not clear how much of this variation is due to extrinsic versus intrinsic factors. We examined this question by determining CORTf in free-living house sparrows (Passer domesticus) from two populations, one urban and the other rural, that were plucked before and after exposure to different plasma CORT levels while held captive. We experimentally manipulated plasma CORT by implanting birds with either a corticosterone-filled, metyrapone-filled, or empty ('sham') silastic capsule as replacement feathers first emerged. The pattern of post-treatment CORTf was consistent with our expectations, based on plasma CORT levels of an experimentally implanted reference group. However, there was no statistically significant difference in CORTf between these treatment groups unless sex, population origin, and CORTf of original feathers for each individual were included in a model. Thus, birds with higher CORTf in feathers removed for this experiment tended to have higher CORTf in post-treatment replacement feathers, irrespective of treatment. In addition, we found that feather fault bar scores were significantly higher in CORT-treated birds than in the other two treatment groups, but did not vary directly with CORTf level. Our study therefore broadly confirms the use of feathers as a non-invasive tool to estimate plasma CORT during moult in birds, but importantly demonstrates the potential for intrinsic differences in stress characteristics between populations and individuals to obscure the effects extrinsic stressors might have on CORTf.
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Affiliation(s)
- Yaara Aharon-Rotman
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Locked Bag 20000, Geelong, VIC 3220, Australia; Department of Zoology, The George S. Wise Faculty of Life Sciences, Tel-Aviv University, Israel.
| | - Katherine L Buchanan
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Locked Bag 20000, Geelong, VIC 3220, Australia
| | - Marcel Klaassen
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Locked Bag 20000, Geelong, VIC 3220, Australia
| | - William A Buttemer
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Locked Bag 20000, Geelong, VIC 3220, Australia
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16
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Broughton DR, Schneider BC, McGraw KJ, Ardia DR. Carotenoids buffer the acute phase response on fever, sickness behavior, and rapid bill color change in zebra finches. J Exp Biol 2017; 220:2957-2964. [DOI: 10.1242/jeb.155069] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 06/01/2017] [Indexed: 12/18/2022]
Abstract
Carotenoids are finite resources that animals can allocate to self-maintenance, attractiveness, or reproduction. Here we test how carotenoids affect the acute phase response (APR), an intense rapid systemic response characterized by fever, sickness behavior, and production of acute phase proteins, which serves to reduce pathogen persistence. We conducted a 2x2 factorial design experiment in captive adult male and female zebra finches (Taeniopygia guttata) to determine the effects of carotenoid supplementation on the intensity of the APR. We measured changes in feeding rate, activity level, and body temperature of the birds. We found that, relative to unsupplemented controls, carotenoid-supplemented birds exhibited less severe reductions in feeding and activity, smaller increases in body temperature, and lower circulating levels of haptoglobin (an acute phase protein) 24 h after inducing an APR. Among supplemented individuals, those with higher blood carotenoid levels exhibited a lower reduction in activity rate after 24 h. Forty-eight hours after APR induction, birds exhibited a significant decrease in plasma carotenoid levels and a decrease in bill hue, with less reduction in hue in carotenoid-supplemented individuals. These results demonstrate that carotenoids can alleviate several important behavioral and physiological effects of an APR and that bill color can change rapidly following induction of the costly APR immune defense. In particular, immune activation may have caused birds to preferentially draw down carotenoids from the bloodstream, ostensibly for use in health. Rapid bill color changes over a 48-hr period support growing evidence that bills may serve as short-term signals of health and condition.
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Affiliation(s)
- Deanna R. Broughton
- Department of Biology, Franklin & Marshall College, Lancaster, PA 17604, USA
| | - Brent C. Schneider
- Department of Biology, Franklin & Marshall College, Lancaster, PA 17604, USA
| | - Kevin J. McGraw
- School of Life Sciences, Arizona State University, Tempe, AZ 85287, USA
| | - Daniel R. Ardia
- Department of Biology, Franklin & Marshall College, Lancaster, PA 17604, USA
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17
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Romero LM, Fairhurst GD. Measuring corticosterone in feathers: Strengths, limitations, and suggestions for the future. Comp Biochem Physiol A Mol Integr Physiol 2016; 202:112-122. [DOI: 10.1016/j.cbpa.2016.05.002] [Citation(s) in RCA: 90] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Revised: 05/02/2016] [Accepted: 05/02/2016] [Indexed: 02/05/2023]
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18
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Lindsay WR, Wapstra E, Silverin B, Olsson M. Corticosterone: a costly mediator of signal honesty in sand lizards. Ecol Evol 2016; 6:7451-7461. [PMID: 28725412 PMCID: PMC5513280 DOI: 10.1002/ece3.2318] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Revised: 06/20/2016] [Accepted: 06/21/2016] [Indexed: 11/17/2022] Open
Abstract
The mechanisms underlying honest signal expression remain elusive and may involve the integration of social and physiological costs. Corticosterone is a socially modulated metabolic hormone that mediates energy investment and behavior and may therefore function to deter dishonest signal expression. We examined the relationship between corticosterone and green badge coloration in male sand lizards (Lacerta agilis), hypothesizing that physiological and behavioral costs resulting from elevated baseline glucocorticoids function in maintenance of honest signal expression. We found that large‐badged males had higher corticosterone titer, with this relationship apparent at the end of the season and absent early in the season. Large‐badged males also suffered higher ectoparasite load (number of tick nymphs), despite being in better condition than small‐badged males. Ectoparasite load was positively related to corticosterone titer early in the season at the time of badge formation. High‐condition individuals had lower corticosterone and lower numbers of ectoparasites than low‐condition individuals, suggestive of conditional variation in ability to withstand costs of corticosterone. We found an opposing negative relationship between corticosterone titer and endoparasite load. Corticosterone titer was also negatively associated with male mobility, a fitness‐determining behavior in this species. Because badge size is involved in mediating agonistic social interactions in this species, our results suggest that badge‐dependent variation in corticosterone is likely reflective of variation in social conditions experienced over the course of the season. Our results implicate corticosterone in maintenance of signal honesty, both early in the season through enforcement of physiological costs (ectoparasite load) and during the season through behavioral costs (male mobility). We propose that socially modulated variation in corticosterone critically functions in mediation of signal honesty without requiring a direct role for corticosterone in trait expression.
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Affiliation(s)
- Willow R Lindsay
- Department of Biological and Environmental Sciences Göteborg University Göteborg Sweden
| | - Erik Wapstra
- School of Biological Sciences University of Tasmania Hobart Tas. Australia
| | - Bengt Silverin
- Department of Biological and Environmental Sciences Göteborg University Göteborg Sweden
| | - Mats Olsson
- Department of Biological and Environmental Sciences Göteborg University Göteborg Sweden.,School of Biological Sciences University of Sydney Sydney NSW Australia
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19
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Scheiber IBR, Sterenborg M, Komdeur J. Stress assessment in captive greylag geese (Anser anser). J Anim Sci 2016; 93:2124-33. [PMID: 26020308 DOI: 10.2527/jas.2014-8523] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Chronic stress--or, more appropriately, "allostatic overload"--may be physiologically harmful and can cause death in the most severe cases. Animals in captivity are thought to be particularly vulnerable to allostatic overload due to artificial housing and group makeup. Here we attempted to determine if captive greylag geese (Anser anser), housed lifelong in captivity, showed elevated levels of immunoreactive corticosterone metabolites (CORT) and ectoparasites in dropping samples as well as some hematological parameters (hematocrit, packed cell volume, total white blood cell count [TWBC], and heterophil:lymphocyte ratio [H:L]). All of these have been measured as indicators of chronic stress. Furthermore, we correlated the various stress parameters within individuals. Captive geese showed elevated values of CORT and ectoparasites relative to a wild population sampled in the vicinity of the area where the captive flock is held. The elevated levels, however, were by no means at a pathological level and fall well into the range of other published values in wild greylag geese. We found no correlations between any of the variables measured from droppings with any of the ones collected from blood. Among the blood parameters, only the H:L negatively correlated with TWBC. We examine the problem of inferring allostatic overload when measuring only 1 stress parameter, as there is no consistency between various measurements taken. We discuss the different aspects of each of the parameters measured and the extensive individual variation in response to stress as well as the timing at which different systems respond to a stressor and what is actually measured at the time of data collection. We conclude that measuring only 1 stress parameter often is insufficient to evaluate the well-being of both wild and captively housed animals and that collecting behavioral data on stress might be a suitable addition.
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20
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Frigerio D, Cibulski L, Ludwig SC, Campderrich I, Kotrschal K, Wascher CAF. Excretion patterns of coccidian oocysts and nematode eggs during the reproductive season in Northern Bald Ibis ( Geronticus eremita). JOURNAL OF ORNITHOLOGY 2016; 157:839-851. [PMID: 27570727 PMCID: PMC4986318 DOI: 10.1007/s10336-015-1317-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Revised: 10/29/2015] [Accepted: 12/08/2015] [Indexed: 06/06/2023]
Abstract
Individual reproductive success largely depends on the ability to optimize behaviour, immune function and the physiological stress response. We have investigated correlations between behaviour, faecal steroid metabolites, immune parameters, parasite excretion patterns and reproductive output in a critically endangered avian species, the Northern Bald Ibis (Geronticus eremita). In particular, we related haematocrit, heterophil/lymphocyte ratio, excreted immune-reactive corticosterone metabolites and social behaviour with parasite excretion and two individual fitness parameters, namely, number of eggs laid and number of fledglings. We found that the frequency of excretion of parasites' oocysts and eggs tended to increase with ambient temperature. Paired individuals excreted significantly more samples containing nematode eggs than unpaired ones. The excretion of nematode eggs was also significantly more frequent in females than in males. Individuals with a high proportion of droppings containing coccidian oocysts were more often preened by their partners than individuals with lower excretion rates. We observed that the more eggs an individual incubated and the fewer offspring fledged, the higher the rates of excreted samples containing coccidian oocysts. Our results confirm that social behaviour, physiology and parasite burden are linked in a complex and context-dependent manner. They also contribute background information supporting future conservation programmes dealing with this critically endangered species.
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Affiliation(s)
- Didone Frigerio
- Core Facility Konrad Lorenz Forschungsstelle for Behaviour and Cognition, University of Vienna, Fischerau 11, 4645 Grünau im Almtal, Austria
- Department of Behavioural Biology, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
| | - Lara Cibulski
- Core Facility Konrad Lorenz Forschungsstelle for Behaviour and Cognition, University of Vienna, Fischerau 11, 4645 Grünau im Almtal, Austria
| | - Sonja C. Ludwig
- Core Facility Konrad Lorenz Forschungsstelle for Behaviour and Cognition, University of Vienna, Fischerau 11, 4645 Grünau im Almtal, Austria
- Game & Wildlife Conservation Trust, The Coach House, Eggleston Hall, Barnard Castle, DG12 0AG UK
| | - Irene Campderrich
- Core Facility Konrad Lorenz Forschungsstelle for Behaviour and Cognition, University of Vienna, Fischerau 11, 4645 Grünau im Almtal, Austria
- Department of Animal Production, Neiker-Tecnalia, Vitoria-Gasteiz, Spain
| | - Kurt Kotrschal
- Core Facility Konrad Lorenz Forschungsstelle for Behaviour and Cognition, University of Vienna, Fischerau 11, 4645 Grünau im Almtal, Austria
- Department of Behavioural Biology, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
| | - Claudia A. F. Wascher
- Core Facility Konrad Lorenz Forschungsstelle for Behaviour and Cognition, University of Vienna, Fischerau 11, 4645 Grünau im Almtal, Austria
- Animal and Environment Research Group, Department of Life Sciences, Anglia Ruskin University, Cambridge, UK
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21
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Mougeot F, Lendvai ÁZ, Martínez-Padilla J, Pérez-Rodríguez L, Giraudeau M, Casas F, Moore IT, Redpath S. Parasites, mate attractiveness and female feather corticosterone levels in a socially monogamous bird. Behav Ecol Sociobiol 2015. [DOI: 10.1007/s00265-015-2048-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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22
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Wenzel MA, Douglas A, James MC, Redpath SM, Piertney SB. The role of parasite-driven selection in shaping landscape genomic structure in red grouse (Lagopus lagopus scotica). Mol Ecol 2015; 25:324-41. [PMID: 26578090 DOI: 10.1111/mec.13473] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Revised: 11/09/2015] [Accepted: 11/10/2015] [Indexed: 12/25/2022]
Abstract
Landscape genomics promises to provide novel insights into how neutral and adaptive processes shape genome-wide variation within and among populations. However, there has been little emphasis on examining whether individual-based phenotype-genotype relationships derived from approaches such as genome-wide association (GWAS) manifest themselves as a population-level signature of selection in a landscape context. The two may prove irreconcilable as individual-level patterns become diluted by high levels of gene flow and complex phenotypic or environmental heterogeneity. We illustrate this issue with a case study that examines the role of the highly prevalent gastrointestinal nematode Trichostrongylus tenuis in shaping genomic signatures of selection in red grouse (Lagopus lagopus scotica). Individual-level GWAS involving 384 SNPs has previously identified five SNPs that explain variation in T. tenuis burden. Here, we examine whether these same SNPs display population-level relationships between T. tenuis burden and genetic structure across a small-scale landscape of 21 sites with heterogeneous parasite pressure. Moreover, we identify adaptive SNPs showing signatures of directional selection using F(ST) outlier analysis and relate population- and individual-level patterns of multilocus neutral and adaptive genetic structure to T. tenuis burden. The five candidate SNPs for parasite-driven selection were neither associated with T. tenuis burden on a population level, nor under directional selection. Similarly, there was no evidence of parasite-driven selection in SNPs identified as candidates for directional selection. We discuss these results in the context of red grouse ecology and highlight the broader consequences for the utility of landscape genomics approaches for identifying signatures of selection.
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Affiliation(s)
- Marius A Wenzel
- Institute of Biological and Environmental Sciences, University of Aberdeen, Tillydrone Avenue, Aberdeen, AB24 2TZ, UK
| | - Alex Douglas
- Institute of Biological and Environmental Sciences, University of Aberdeen, Tillydrone Avenue, Aberdeen, AB24 2TZ, UK
| | - Marianne C James
- Institute of Biological and Environmental Sciences, University of Aberdeen, Tillydrone Avenue, Aberdeen, AB24 2TZ, UK
| | - Steve M Redpath
- Institute of Biological and Environmental Sciences, University of Aberdeen, Tillydrone Avenue, Aberdeen, AB24 2TZ, UK
| | - Stuart B Piertney
- Institute of Biological and Environmental Sciences, University of Aberdeen, Tillydrone Avenue, Aberdeen, AB24 2TZ, UK
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23
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Moore FR, Shuker DM, Dougherty L. Stress and sexual signaling: a systematic review and meta-analysis. Behav Ecol 2015. [DOI: 10.1093/beheco/arv195] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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24
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Cizauskas CA, Turner WC, Pitts N, Getz WM. Seasonal patterns of hormones, macroparasites, and microparasites in wild African ungulates: the interplay among stress, reproduction, and disease. PLoS One 2015; 10:e0120800. [PMID: 25875647 PMCID: PMC4398380 DOI: 10.1371/journal.pone.0120800] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Accepted: 02/06/2015] [Indexed: 01/19/2023] Open
Abstract
Sex hormones, reproductive status, and pathogen load all affect stress. Together with stress, these factors can modulate the immune system and affect disease incidence. Thus, it is important to concurrently measure these factors, along with their seasonal fluctuations, to better understand their complex interactions. Using steroid hormone metabolites from fecal samples, we examined seasonal correlations among zebra and springbok stress, reproduction, gastrointestinal (GI) parasite infections, and anthrax infection signatures in zebra and springbok in Etosha National Park (ENP), Namibia, and found strong seasonal effects. Infection intensities of all three GI macroparasites examined (strongyle helminths, Strongyloides helminths, and Eimeria coccidia) were highest in the wet season, concurrent with the timing of anthrax outbreaks. Parasites also declined with increased acquired immune responses. We found hormonal evidence that both mares and ewes are overwhelmingly seasonal breeders in ENP, and that reproductive hormones are correlated with immunosuppression and higher susceptibility to GI parasite infections. Stress hormones largely peak in the dry season, particularly in zebra, when parasite infection intensities are lowest, and are most strongly correlated with host mid-gestation rather than with parasite infection intensity. Given the evidence that GI parasites can cause host pathology, immunomodulation, and immunosuppression, their persistence in ENP hosts without inducing chronic stress responses supports the hypothesis that hosts are tolerant of their parasites. Such tolerance would help to explain the ubiquity of these organisms in ENP herbivores, even in the face of their potential immunomodulatory trade-offs with anti-anthrax immunity.
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Affiliation(s)
- Carrie A. Cizauskas
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, CA, United States of America
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, United States of America
| | - Wendy C. Turner
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, CA, United States of America
- Centre for Ecological and Evolutionary Synthesis, Department of Biosciences, University of Oslo, Oslo, Norway
| | - Neville Pitts
- School of Physiology, University of the Witwatersrand, Johannesburg, South Africa
| | - Wayne M. Getz
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, CA, United States of America
- School of Mathematical Sciences, University of KwaZulu-Natal, Durban, South Africa
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25
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Strong RJ, Pereira MG, Shore RF, Henrys PA, Pottinger TG. Feather corticosterone content in predatory birds in relation to body condition and hepatic metal concentration. Gen Comp Endocrinol 2015; 214:47-55. [PMID: 25776461 DOI: 10.1016/j.ygcen.2015.03.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Revised: 02/27/2015] [Accepted: 03/06/2015] [Indexed: 11/18/2022]
Abstract
This study investigated the feasibility of measuring corticosterone in feathers from cryo-archived raptor specimens, in order to provide a retrospective assessment of the activity of the stress axis in relation to contaminant burden. Feather samples were taken from sparrowhawk Accipiter nisus, kestrel Falco tinnunculus, buzzard Buteo buteo, barn owl Tyto alba, and tawny owl Strix aluco and the variation in feather CORT concentrations with respect to species, age, sex, feather position, and body condition was assessed. In sparrowhawks only, variation in feather CORT content was compared with hepatic metal concentrations. For individuals, CORT concentration (pgmm(-1)) in adjacent primary flight feathers (P5 and P6), and left and right wing primaries (P5), was statistically indistinguishable. The lowest concentrations of CORT were found in sparrowhawk feathers and CORT concentrations did not vary systematically with age or sex for any species. Significant relationships between feather CORT content and condition were observed in only tawny owl and kestrel. In sparrowhawks, feather CORT concentration was found to be positively related to the hepatic concentrations of five metals (Cd, Mn, Co, Cu, Mo) and the metalloid As. There was also a negative relationship between measures of condition and total hepatic metal concentration in males. The results suggest that some factors affecting CORT uptake by feathers remain to be resolved but feather CORT content from archived specimens has the potential to provide a simple effects biomarker for exposure to environmental contaminants.
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Affiliation(s)
- Rebecca J Strong
- Centre for Ecology & Hydrology, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster LA1 4AP, United Kingdom; University of Lancaster, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster LA1 4YQ, United Kingdom
| | - M Glória Pereira
- Centre for Ecology & Hydrology, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster LA1 4AP, United Kingdom
| | - Richard F Shore
- Centre for Ecology & Hydrology, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster LA1 4AP, United Kingdom
| | - Peter A Henrys
- Centre for Ecology & Hydrology, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster LA1 4AP, United Kingdom
| | - Tom G Pottinger
- Centre for Ecology & Hydrology, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster LA1 4AP, United Kingdom.
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26
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Wenzel MA, Piertney SB. Digging for gold nuggets: uncovering novel candidate genes for variation in gastrointestinal nematode burden in a wild bird species. J Evol Biol 2015; 28:807-25. [DOI: 10.1111/jeb.12614] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Revised: 02/13/2015] [Accepted: 02/16/2015] [Indexed: 12/16/2022]
Affiliation(s)
- M. A. Wenzel
- Institute of Biological and Environmental Sciences; University of Aberdeen; Aberdeen UK
| | - S. B. Piertney
- Institute of Biological and Environmental Sciences; University of Aberdeen; Aberdeen UK
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27
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Warne RW, Proudfoot GA, Crespi EJ. Biomarkers of animal health: integrating nutritional ecology, endocrine ecophysiology, ecoimmunology, and geospatial ecology. Ecol Evol 2015; 5:557-66. [PMID: 25691980 PMCID: PMC4328761 DOI: 10.1002/ece3.1360] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Accepted: 11/17/2014] [Indexed: 11/25/2022] Open
Abstract
Diverse biomarkers including stable isotope, hormonal, and ecoimmunological assays are powerful tools to assess animal condition. However, an integrative approach is necessary to provide the context essential to understanding how biomarkers reveal animal health in varied ecological conditions. A barrier to such integration is a general lack of awareness of how shared extraction methods from across fields can provide material from the same animal tissues for diverse biomarker assays. In addition, the use of shared methods for extracting differing tissue fractions can also provide biomarkers for how animal health varies across time. Specifically, no study has explicitly illustrated the depth and breadth of spacial and temporal information that can be derived from coupled biomarker assessments on two easily collected tissues: blood and feathers or hair. This study used integrated measures of glucocorticoids, stable isotopes, and parasite loads in the feathers and blood of fall-migrating Northern saw-whet owls (Aegolius acadicus) to illustrate the wealth of knowledge about animal health and ecology across both time and space. In feathers, we assayed deuterium (δD) isotope and corticosterone (CORT) profiles, while in blood we measured CORT and blood parasite levels. We found that while earlier migrating owls had elevated CORT levels relative to later migrating birds, there was also a disassociation between plasma and feather CORT, and blood parasite loads. These results demonstrate how these tissues integrate time periods from weeks to seasons and reflect energetic demands during differing life stages. Taken together, these findings illustrate the potential for integrating diverse biomarkers to assess interactions between environmental factors and animal health across varied time periods without the necessity of continually recapturing and tracking individuals. Combining biomarkers from diverse research fields into an integrated framework hold great promise for advancing our understanding of environmental effects on animal health.
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Affiliation(s)
- Robin W Warne
- Department of Biology, Vassar College 124 Raymond Ave, Poughkeepsie, New York, 12604
| | - Glenn A Proudfoot
- Department of Biology, Vassar College 124 Raymond Ave, Poughkeepsie, New York, 12604
| | - Erica J Crespi
- Department of Biology, Vassar College 124 Raymond Ave, Poughkeepsie, New York, 12604
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28
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Vergara P, Fargallo JA, Martínez-Padilla J. Genetic basis and fitness correlates of dynamic carotenoid-based ornamental coloration in male and female common kestrels Falco tinnunculus. J Evol Biol 2014; 28:146-54. [DOI: 10.1111/jeb.12553] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Accepted: 11/12/2014] [Indexed: 11/28/2022]
Affiliation(s)
- P. Vergara
- Departamento de Ecología Evolutiva; Museo Nacional de Ciencias Naturales-CSIC; Madrid Spain
| | - J. A. Fargallo
- Departamento de Ecología Evolutiva; Museo Nacional de Ciencias Naturales-CSIC; Madrid Spain
| | - J. Martínez-Padilla
- Departamento de Ecología Evolutiva; Museo Nacional de Ciencias Naturales-CSIC; Madrid Spain
- Department of Ethology and Biodiversity Conservation; Estación Biológica de Doñana - CSIC; Sevilla Spain
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29
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Grunst ML, Grunst AS, Parker CE, Romero LM, Rotenberry JT. Pigment-specific relationships between feather corticosterone concentrations and sexual coloration. Behav Ecol 2014. [DOI: 10.1093/beheco/aru210] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
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30
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Fairhurst GD, Dawson RD, van Oort H, Bortolotti GR. Synchronizing feather-based measures of corticosterone and carotenoid-dependent signals: what relationships do we expect? Oecologia 2014; 174:689-98. [PMID: 24233689 DOI: 10.1007/s00442-013-2830-5] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Accepted: 11/04/2013] [Indexed: 02/03/2023]
Abstract
Carotenoids produce many of the red, orange and yellow signal traits of birds, and individuals must trade off utilizing carotenoids for physiological processes versus ornamentation. Proximate mechanisms regulating this trade-off are poorly understood, despite their importance for expression of color signals. Corticosterone (CORT) may play a significant mechanistic role in signal expression because it mobilizes energy substrates and influences foraging behavior. We used a unique feather-based approach to test whether CORT mediates expression of carotenoid-based coloration. First, we investigated relationships between levels of CORT from feathers (CORT(f)) and carotenoid-based plumage signals in common redpolls (Acanthis flammea). Then, we determined how the width of growth bars and probability of having fault bars on feathers varied with CORT(f), specifically whether these metrics reflected developmental costs of elevated CORT ("stress" hypothesis) or represented an individual's quality ("quality" hypothesis). CORT(f) correlated positively with the strength of carotenoid signals, but only in adult males. However, also in adult males, CORT(f) was positively related to width of feather growth bars and negatively with probability of having fault bars, providing support for the quality hypothesis. Overall, CORT(f) was lower in adult males than in females or young males, possibly due to dominance patterns. Our results indicate that CORT may indirectly benefit feather quality, potentially by mediating the expression of carotenoid signals. We place our sex-specific findings into a novel framework that proposes that the influences of CORT in mediating carotenoid-based plumage traits will depend on the extent to which carotenoids are traded off between competing functions.
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31
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The Relationships between Parasite Intensity, Locomotor Performance, and Body Condition in Adult Toads (Rhinella icterica) from the Wild. J HERPETOL 2014. [DOI: 10.1670/10-339] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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32
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Sild E, Meitern R, Männiste M, Karu U, Hõrak P. High feather corticosterone indicates better coccidian infection resistance in greenfinches. Gen Comp Endocrinol 2014; 204:203-10. [PMID: 24953456 DOI: 10.1016/j.ygcen.2014.05.026] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Revised: 04/21/2014] [Accepted: 05/19/2014] [Indexed: 11/22/2022]
Abstract
Differential exposure or sensitivity to stressors can have substantial effects on the variation in immune responsiveness of animals. However, the questions about the causes and consequences of these processes have remained largely unclear, particularly as regards wild animals and their natural pathogens. Here we ask how a potential marker of stress responses, the feather corticosterone (CORT) content, reflects the resistance to an experimental infection with natural coccidian parasites in wild-caught captive greenfinches (Carduelis chloris). CORT content of tail feathers grown in captivity correlated positively with a behavioural measure of captivity-intolerance, i.e., the amount of damage accrued to tail feathers in captivity that results from flapping against cage bars. This finding is consistent with an idea that feather CORT reflects the amount of stress experienced during feather growth. Experimental infection with heterologous coccidian strains increased feather CORT levels. Birds with highest feather CORT levels appeared most resistant to new infection, assessed on the basis of parasite oocyst shedding at the peak phase of infection. Birds with highest feather CORT levels also cleared the infection faster than the birds with lower feather CORT levels. These findings provide the first evidence about positive covariation between feather CORT and resistance to a natural pathogen in a wild bird species. Assuming that feather CORT levels reflect circulating hormone titres, these findings suggest that parasite-mediated selection may contribute to maintenance of phenotypes with high corticosterone responsiveness to stress, despite potential negative behavioural consequences.
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Affiliation(s)
- Elin Sild
- Department of Zoology, Institute of Ecology and Earth Sciences, Tartu University, Vanemuise 46, 51014 Tartu, Estonia
| | - Richard Meitern
- Department of Zoology, Institute of Ecology and Earth Sciences, Tartu University, Vanemuise 46, 51014 Tartu, Estonia
| | - Marju Männiste
- Department of Zoology, Institute of Ecology and Earth Sciences, Tartu University, Vanemuise 46, 51014 Tartu, Estonia
| | - Ulvi Karu
- Department of Zoology, Institute of Ecology and Earth Sciences, Tartu University, Vanemuise 46, 51014 Tartu, Estonia
| | - Peeter Hõrak
- Department of Zoology, Institute of Ecology and Earth Sciences, Tartu University, Vanemuise 46, 51014 Tartu, Estonia.
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Wenzel MA, Piertney SB. Fine-scale population epigenetic structure in relation to gastrointestinal parasite load in red grouse (Lagopus lagopus scotica). Mol Ecol 2014; 23:4256-73. [PMID: 24943398 PMCID: PMC4282444 DOI: 10.1111/mec.12833] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Revised: 06/10/2014] [Accepted: 06/11/2014] [Indexed: 12/27/2022]
Abstract
Epigenetic modification of cytosine methylation states can be elicited by environmental stresses and may be a key process affecting phenotypic plasticity and adaptation. Parasites are potent stressors with profound physiological and ecological effects on their host, but there is little understanding in how parasites may influence host methylation states. Here, we estimate epigenetic diversity and differentiation among 21 populations of red grouse (Lagopus lagopus scotica) in north-east Scotland and test for association of gastrointestinal parasite load (caecal nematode Trichostrongylus tenuis) with hepatic genome-wide and locus-specific methylation states. Following methylation-sensitive AFLP (MSAP), 129 bands, representing 73 methylation-susceptible and 56 nonmethylated epiloci, were scored across 234 individuals. The populations differed significantly in genome-wide methylation levels and were also significantly epigenetically (FSC = 0.0227; P < 0.001) and genetically (FSC = 0.0058; P < 0.001) differentiated. Parasite load was not associated with either genome-wide methylation levels or epigenetic differentiation. Instead, we found eight disproportionately differentiated epilocus-specific methylation states (FST outliers) using bayescan software and significant positive and negative association of 35 methylation states with parasite load from bespoke generalized estimating equations (GEE), simple logistic regression (sam) and Bayesian environmental analysis (bayenv2). Following Sanger sequencing, genome mapping and geneontology (go) annotation, some of these epiloci were linked to genes involved in regulation of cell cycle, signalling, metabolism, immune system and notably rRNA methylation, histone acetylation and small RNAs. These findings demonstrate an epigenetic signature of parasite load in populations of a wild bird and suggest intriguing physiological effects of parasite-associated cytosine methylation.
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Affiliation(s)
- Marius A Wenzel
- Institute of Biological and Environmental Sciences, University of Aberdeen, Zoology Building, Tillydrone Avenue, Aberdeen, AB24 2TZ, UK
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Bestman M, Wagenaar JP. Health and Welfare in Dutch Organic Laying Hens. Animals (Basel) 2014; 4:374-90. [PMID: 26480046 PMCID: PMC4494376 DOI: 10.3390/ani4020374] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Revised: 06/03/2014] [Accepted: 06/04/2014] [Indexed: 11/16/2022] Open
Abstract
From 2007-2008, data on animal health and welfare and farm management during rearing and laying periods were collected from 49 flocks of organic laying hens in the Netherlands. Our aim was to investigate how organic egg farms performed in terms of animal health and welfare and which farm factors affected this performance. The flocks in our study were kept on farms with 34 to 25,000 hens (average 9,300 hens). Seventy-one percent of the flocks consisted of 'silver hybrids': white hens that lay brown eggs. Fifty-five percent of the flocks were kept in floor-based housing and 45% of the flocks in aviaries. No relation was found between the amount of time spent outdoors during the laying period and mortality at 60 weeks. Flocks that used their outdoor run more intensively had better feather scores. In 40% of the flocks there was mortality caused by predators. The average feed intake was 129 g/day at 30 weeks and 133 g/day at 60 weeks of age. The average percentage of mislaid eggs decreased from three at 30 weeks to two at 60 weeks. The average mortality was 7.8% at 60 weeks. Twenty-five percent of the flocks were not treated for worms in their first 50 weeks. Flubenol(©) was applied to the flocks that were treated. Ten percent of the flocks followed Flubenol(©) instructions for use and were wormed five or more times. The other 65% percent were treated irregularly between one and four times. Sixty-eight percent of the flocks showed little or no feather damage, 24% showed moderate damage and 8% showed severe damage. The feather score was better if the hens used the free-range area more intensely, the laying percentage at 60 weeks was higher, and if they were allowed to go outside sooner after arrival on the laying farm. In 69% of the flocks, hens had peck wounds in the vent area: on average this was 18% of the hens. Keel bone deformations were found in all flocks, on average in 21% of the birds. In 78% of the flocks, an average of 13% of the hens had foot-sole wounds, mostly a small crust. Combs were darker in flocks that used the range area more intensively. More fearful flocks had lighter combs. We conclude that organic farms are potentially more animal friendly than other poultry systems based on the animal welfare benefits of the free range areas. However, we also observed mortality rates, internal parasites, keel bone deformities, and foot sole lesions on organic farms that were comparable to or worse than in other husbandry systems. It is unclear whether these 'remaining' problems can be attributed to housing or if they are the result of keeping high productive genotypes in an artificial environment. Organic farms use the same high productive genotypes as other husbandry systems.
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Affiliation(s)
- Monique Bestman
- Louis Bolk Institute, Hoofdstraat 24, 3972 LA, Driebergen, The Netherlands.
| | - Jan-Paul Wagenaar
- Louis Bolk Institute, Hoofdstraat 24, 3972 LA, Driebergen, The Netherlands.
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Martínez-Padilla J, Pérez-Rodríguez L, Mougeot F, Ludwig S, Redpath SM. Intra-sexual competition alters the relationship between testosterone and ornament expression in a wild territorial bird. Horm Behav 2014; 65:435-44. [PMID: 24698833 DOI: 10.1016/j.yhbeh.2014.03.012] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2013] [Revised: 03/18/2014] [Accepted: 03/22/2014] [Indexed: 01/21/2023]
Abstract
In a reliable signalling system, individual quality is expected to mediate the costs associated with ornamental displays, with relatively lower costs being paid by individuals of higher quality. These relative costs should depend not only on individual quality, but also on levels of intra-sexual competition. We explored the current and delayed effects that testosterone implants have on bird ornamentation in populations with contrasted population densities, as a proxy for intra-sexual competition. In a replicated experiment, we manipulated testosterone in 196 yearling male red grouse Lagopus lagopus scoticus in autumn in populations of high and low levels of intra-sexual competition. Males were assigned to one of three exogenous testosterone (T) treatments: empty implants (T0), small T implants (T1) or larger T implants (T2). We monitored subsequent changes in testosterone levels, ornament size and carotenoid-based colouration, carotenoid levels and body condition from autumn to spring. Testosterone implants increased testosterone levels, comb redness and comb size, and decreased body condition but these effects depended on levels of intra-sexual competition. Specifically, T2-implanted birds increased testosterone levels and comb size more, and reduced body condition more, in populations where intra-sexual competition was low. In the following spring, testosterone levels of T2-treated birds kept increasing in populations where intra-sexual competition was high but not in populations where intra-sexual competition was low. Our results highlight that levels of intra-sexual competition alter the relationship between testosterone levels and ornament expression, influencing their condition-dependence; they also indicate that the outcome of standard hormone manipulation conducted in free-living animals vary depending on the population context.
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Affiliation(s)
- J Martínez-Padilla
- Department of Evolutionary Ecology, Museo Nacional de Ciencias Naturales, José Gutiérrez Abascal, 2, 23005, Madrid, Spain.
| | - L Pérez-Rodríguez
- Instituto de Investigación en Recursos Cinegéticos, IREC (CSIC, UCLM, JCCM), Ronda de Toledo, s/n, 3005 Ciudad Real, Spain; Department of Evolutionary Ecology, Estación Biológica de Doñana, (EBD-CSIC), Avda. Americo Vespucio, s/n, 41092 Seville, Spain
| | - F Mougeot
- Instituto de Investigación en Recursos Cinegéticos, IREC (CSIC, UCLM, JCCM), Ronda de Toledo, s/n, 3005 Ciudad Real, Spain; Estación Experimental de Zonas Áridas (CSIC), Ctra. de Sacramento s/n, La Cañada de San Urbano, 04120 Almería, Spain
| | - S Ludwig
- Game & Wildlife Conservation Trust, Eggleston Hall, Barnard Castle, DL12 0AG UK
| | - S M Redpath
- School of Biological Sciences, University of Aberdeen, Tillydrone Avenue, Aberdeen AB24 2TZ, UK
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Yang C, Wang J, Fang Y, Sun YH. Is sexual ornamentation an honest signal of male quality in the Chinese grouse (Tetrastes sewerzowi)? PLoS One 2013; 8:e82972. [PMID: 24386132 PMCID: PMC3873284 DOI: 10.1371/journal.pone.0082972] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2013] [Accepted: 11/01/2013] [Indexed: 11/22/2022] Open
Abstract
We examined the variation in sexual ornamentation of male Chinese grouse (Tetrastes sewerzowi) in the Gansu Province, China, seeking to identify factors involved in whether ornament size and brightness are honest signals of male quality. Compared to unmated males, mated males had significantly larger and redder combs and, although they did not have significantly larger territories, they defended them more vigorously. Mated males had significantly higher blood carotenoid and testosterone levels, significantly better body condition, and significantly lower parasite loads than unmated males. Our findings are thus consistent with the hypothesis that comb size and color are honest signals of better male quality in the grouse, mediated through lower parasite loads and/or higher testosterone levels.
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Affiliation(s)
- Chen Yang
- Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences Institute of Zoology, Chinese Academy of Sciences, Beijing, P. R. of China
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, Sichuan, P. R. of China
| | - Jie Wang
- Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences Institute of Zoology, Chinese Academy of Sciences, Beijing, P. R. of China
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, Sichuan, P. R. of China
| | - Yun Fang
- Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences Institute of Zoology, Chinese Academy of Sciences, Beijing, P. R. of China
| | - Yue-Hua Sun
- Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences Institute of Zoology, Chinese Academy of Sciences, Beijing, P. R. of China
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Hõrak P, Männiste M, Meitern R, Sild E, Saks L, Sepp T. Dexamethasone inhibits corticosterone deposition in feathers of greenfinches. Gen Comp Endocrinol 2013; 191:210-4. [PMID: 23856540 DOI: 10.1016/j.ygcen.2013.07.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2013] [Revised: 07/01/2013] [Accepted: 07/04/2013] [Indexed: 01/28/2023]
Abstract
Corticosterone (CORT) content of feathers is a potent source of information about activation of hypothalamus-pituitary-adrenal (HPA) axis during feather growth, which is used for assessment of well-being and stress history of individuals and populations in avian studies. However, little is known about factors affecting deposition of CORT into feathers and how feather CORT covaries with other markers of stress imposed upon individuals during feather growth. We addressed these questions by measuring CORT levels in feathers of wild-caught greenfinches (Carduelis chloris) brought into captivity. One tail feather was removed from all the birds upon arrival to the laboratory and the CORT levels of replacement feathers, grown in captivity were recorded. The birds were subjected to treatments of immune activation (by injection of phytohaemagglutinin) and synthetic glucocorticoid (dexamethasone, DEX) administration. Only DEX injection affected feather CORT levels. DEX-injected birds deposited on average 37% less of CORT in their feathers than saline-injected birds. Despite significant effects of DEX and immune activation treatments on differential leukocyte counts, we did not find any correlations between CORT and leukocyte hemoconcentrations or heterophil/lymphocyte ratios (a haematological index of stress), measured at three stages of feather growth. Our findings provide novel evidence that feather CORT levels are sensitive to manipulation of hormonal balance of birds, thereby supporting the diagnostic value of feather CORT measurements. However, we did not find any evidence about covariation between feather CORT and other markers of stress perceived during the period of feather growth. This calls for further research on information content of feather CORT, preferably in experiments manipulating more diverse array of psychological, immunological and abiotic stressors.
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Affiliation(s)
- Peeter Hõrak
- Department of Zoology, Institute of Ecology and Earth Sciences, Tartu University, Vanemuise 46, 51014 Tartu, Estonia.
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Carotenoid-based plumage coloration reflects feather corticosterone levels in male house finches (Haemorhous mexicanus). Behav Ecol Sociobiol 2013. [DOI: 10.1007/s00265-013-1591-9] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Henderson LJ, Heidinger BJ, Evans NP, Arnold KE. Ultraviolet crown coloration in female blue tits predicts reproductive success and baseline corticosterone. Behav Ecol 2013. [DOI: 10.1093/beheco/art066] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Fairhurst GD, Marchant TA, Soos C, Machin KL, Clark RG. Experimental relationships between levels of corticosterone in plasma and feathers in a free-living bird. ACTA ACUST UNITED AC 2013; 216:4071-81. [PMID: 23913947 DOI: 10.1242/jeb.091280] [Citation(s) in RCA: 81] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Integrated measures of corticosterone (CORT), such as from feathers (CORTf), have intuitive appeal because they incorporate both the duration and amplitude of glucocorticoid secretion. An association between CORTf and plasma CORT has never been shown in wild birds, and it is unclear as to when and whether these measures should be correlated, given that they are fundamentally different yet related measures of physiology. We hypothesized that CORTf should correlate with instantaneous measurements of plasma CORT when the latter reflect sustained changes in the activity of the hypothalamic-pituitary-adrenal (HPA) axis. To test this, we experimentally manipulated levels of plasma CORT in wild nestling tree swallows (Tachycineta bicolor) using 5 day time-release CORT pellets, and measured plasma CORT and growth parameters before, during and at the end of hormone manipulation (days 7, 9 and 11 post-hatch, respectively). CORTf and plasma CORT were significantly positively related only when the latter was at its highest and most variable among individuals (day 9). A similar relationship was expected at day 11, but plasma CORT had returned to near-original levels. Nestlings with higher CORTf were smaller, lighter and less likely to fledge, but we did not detect seasonal effects on CORTf. Our results clearly demonstrate that CORTf from free-living birds can reflect plasma CORT, but correlations may not always be expected, especially if elevations in plasma CORT are relatively modest and of short duration. Our work suggests that CORTf is best used to study the activity of the HPA axis over relatively long time frames and can be used effectively to advance avian ecology.
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Affiliation(s)
- Graham D Fairhurst
- Department of Biology, University of Saskatchewan, 112 Science Place, Saskatoon, Saskatchewan, Canada, S7N 5E2
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42
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Wenzel MA, Webster LMI, Paterson S, Mougeot F, Martínez-Padilla J, Piertney SB. A transcriptomic investigation of handicap models in sexual selection. Behav Ecol Sociobiol 2012. [DOI: 10.1007/s00265-012-1442-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Sternalski A, Mougeot F, Pérez-Rodríguez L, Bretagnolle V. Carotenoid-based coloration, condition, and immune responsiveness in the nestlings of a sexually dimorphic bird of prey. Physiol Biochem Zool 2012; 85:364-75. [PMID: 22705486 DOI: 10.1086/665981] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
In many birds, nestlings exhibit brightly colored traits that are pigmented by carotenoids. Carotenoids are diet limited and also serve important health-related physiological functions. The proximate mechanisms behind the expression of these carotenoid-pigmented traits are still poorly known, especially in nestlings with sexual size dimorphism. In these nestlings, intrabrood competition levels and growth strategies likely differ between sexes, and this may in turn influence carotenoid allocation rules. We used dietary carotenoid supplementation to test whether wild marsh harrier (Circus aeruginosus) nestlings were carotenoid limited and whether carotenoid allocation strategies varied between sexes, which differ in their size and growth strategies. When supplemented, nestlings used the supplemental carotenoids to increase their coloration independently of their sex. We showed that the condition dependence of the carotenoid level and the response to an immune challenge (phytohemagglutinin test) differed between sexes, possibly because sexual size dimorphism influences growth strategies and/or intrabrood competition levels and access to different types of food. In this species, which often feeds on mammals, a trade-off likely exists between food quantity (energy) and quality (carotenoid content). Finally, carotenoid-based coloration expressed in marsh harrier nestlings appeared to be indicative of immune responsiveness rather than condition, therefore potentially advertising to parents nestling quality or value rather than nutritional need.
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Affiliation(s)
- Audrey Sternalski
- Instituto de Investigación en Recursos Cinegéticos, Consejo Superior de Investigaciones Cientificas, Universidad de Castilla-La Mancha, Junta de Comunidades de Castilla-La Mancha, Ronda de Toledo s/n, 13005 Ciudad Real, Spain.
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Butler MW, McGraw KJ. Differential effects of early- and late-life access to carotenoids on adult immune function and ornamentation in mallard ducks (Anas platyrhynchos). PLoS One 2012; 7:e38043. [PMID: 22666443 PMCID: PMC3364205 DOI: 10.1371/journal.pone.0038043] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2012] [Accepted: 05/01/2012] [Indexed: 11/18/2022] Open
Abstract
Environmental conditions early in life can affect an organism’s phenotype at adulthood, which may be tuned to perform optimally in conditions that mimic those experienced during development (Environmental Matching hypothesis), or may be generally superior when conditions during development were of higher quality (Silver Spoon hypothesis). Here, we tested these hypotheses by examining how diet during development interacted with diet during adulthood to affect adult sexually selected ornamentation and immune function in male mallard ducks (Anas platyrhynchos). Mallards have yellow, carotenoid-pigmented beaks that are used in mate choice, and the degree of beak coloration has been linked to adult immune function. Using a 2×2 factorial experimental design, we reared mallards on diets containing either low or high levels of carotenoids (nutrients that cannot be synthesized de novo) throughout the period of growth, and then provided adults with one of these two diets while simultaneously quantifying beak coloration and response to a variety of immune challenges. We found that both developmental and adult carotenoid supplementation increased circulating carotenoid levels during dietary treatment, but that birds that received low-carotenoid diets during development maintained relatively higher circulating carotenoid levels during an adult immune challenge. Individuals that received low levels of carotenoids during development had larger phytohemagglutinin (PHA)-induced cutaneous immune responses at adulthood; however, dietary treatment during development and adulthood did not affect antibody response to a novel antigen, nitric oxide production, natural antibody levels, hemolytic capacity of the plasma, or beak coloration. However, beak coloration prior to immune challenges positively predicted PHA response, and strong PHA responses were correlated with losses in carotenoid-pigmented coloration. In sum, we did not find consistent support for either the Environmental Matching or Silver Spoon hypotheses. We then describe a new hypothesis that should be tested in future studies examining developmental plasticity.
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Affiliation(s)
- Michael W Butler
- School of Life Sciences, Arizona State University, Tempe, Arizona, United States of America.
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Martinez-Padilla J, Vergara P, Mougeot F, Redpath SM. Parasitized mates increase infection risk for partners. Am Nat 2012; 179:811-20. [PMID: 22617268 DOI: 10.1086/665664] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Individuals can gain fitness benefits and costs through their mates. However, studies on sexual selection have tended to focus on genetic benefits. A potentially widespread cost of pairing with a parasitized mate is that doing so will increase an individual's parasite abundance. Such a cost has been overlooked in systems in which parasites are indirectly transmitted. We manipulated the abundance of the nematode parasite Trichostrongylus tenuis, an indirectly transmitted parasite, within pairs of wild red grouse Lagopus lagopus scoticus in spring. Parasite levels were correlated within pairs before the experiment. We removed parasites from males, females, or both members of the pair and evaluated individual parasite uptake over the subsequent breeding period. At the end of the breeding season, an individual's parasite abundance was greater when its mate had not been initially purged of parasites. This cost appeared to be greater for males. We discuss the implications of our results in relation to the costs that parasites may have on sexual selection processes.
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Affiliation(s)
- Jesus Martinez-Padilla
- Department of Evolutionary Ecology, Museo Nacional de Ciencias Naturales, Consejo Superior de Investigaciones Científicas (CSIC), José Gutiérrez Abascal 2, 28006 Madrid, Spain.
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Vergara P, Mougeot F, Martínez-Padilla J, Leckie F, Redpath SM. The condition dependence of a secondary sexual trait is stronger under high parasite infection level. Behav Ecol 2012. [DOI: 10.1093/beheco/arr216] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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VERGARA P, MARTINEZ-PADILLA J, MOUGEOT F, LECKIE F, REDPATH SM. Environmental heterogeneity influences the reliability of secondary sexual traits as condition indicators. J Evol Biol 2011; 25:20-8. [DOI: 10.1111/j.1420-9101.2011.02399.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Tóth Z, Griggio M. Leaders are more attractive: birds with bigger yellow breast patches are followed by more group-mates in foraging groups. PLoS One 2011; 6:e26605. [PMID: 22028920 PMCID: PMC3197525 DOI: 10.1371/journal.pone.0026605] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2011] [Accepted: 09/29/2011] [Indexed: 11/18/2022] Open
Abstract
Social network theory provides a perfect tool to better understand the population-level consequences of how individuals interact and make their decisions; however, this approach is generally overlooked among evolutionary biologists interested in social relationships. Here, we used social network analysis to examine the patterns of leader-follower interactions in relation to individual characteristics in foraging groups of free-living rock sparrows (Petronia petronia). We found that yellow feather ornamentation, a carotenoid-based trait, was the best predictor of leadership: birds with bigger ornaments exerted greater influence in the foraging groups and were followed by more group-mates than less elaborate individuals. An individual's tendency for eliciting followings was not influenced by sex, condition or the level of parental investment. None of the above individual characteristics had significant effect on the tendency of individuals to follow others. Our results indicate that a sexually selected trait can also play a significant role in group coordination and social organization of a species.
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Affiliation(s)
- Zoltán Tóth
- Konrad Lorenz Institute for Ethology, Department of Integrative Biology and Evolution, University of Veterinary Medicine of Vienna, Vienna, Austria
| | - Matteo Griggio
- Konrad Lorenz Institute for Ethology, Department of Integrative Biology and Evolution, University of Veterinary Medicine of Vienna, Vienna, Austria
- * E-mail:
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Rodewald AD, Shustack DP, Jones TM. Dynamic selective environments and evolutionary traps in human-dominated landscapes. Ecology 2011; 92:1781-8. [DOI: 10.1890/11-0022.1] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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