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Wang H, Liu Q, Gui D, Liu Y, Feng X, Qu J, Zhao J, Wei G. Automatedly identify dryland threatened species at large scale by using deep learning. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 917:170375. [PMID: 38280598 DOI: 10.1016/j.scitotenv.2024.170375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 12/27/2023] [Accepted: 01/21/2024] [Indexed: 01/29/2024]
Abstract
Dryland biodiversity is decreasing at an alarming rate. Advanced intelligent tools are urgently needed to rapidly, automatedly, and precisely detect dryland threatened species on a large scale for biological conservation. Here, we explored the performance of three deep convolutional neural networks (Deeplabv3+, Unet, and Pspnet models) on the intelligent recognition of rare species based on high-resolution (0.3 m) satellite images taken by an unmanned aerial vehicle (UAV). We focused on a threatened species, Populus euphratica, in the Tarim River Basin (China), where there has been a severe population decline in the 1970s and restoration has been carried out since 2000. The testing results showed that Unet outperforms Deeplabv3+ and Pspnet when the training samples are lower, while Deeplabv3+ performs best as the dataset increases. Overall, when training samples are 80, Deeplabv3+ had the best overall performance for Populus euphratica identification, with mean pixel accuracy (MPA) between 87.31 % and 90.2 %, which, on average is 3.74 % and 11.29 % higher than Unet and Pspnet, respectively. Deeplabv3+ can accurately detect the boundaries of Populus euphratica even in areas of dense vegetation, with lower identification uncertainty for each pixel than other models. This study developed a UAV imagery-based identification framework using deep learning with high resolution in large-scale regions. This approach can accurately capture the variation in dryland threatened species, especially those in inaccessible areas, thereby fostering rapid and efficient conservation actions.
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Affiliation(s)
- Haolin Wang
- State Key Laboratory of Desert and Oasis Ecology, Key Laboratory of Ecological Safety and Sustainable Development in Arid Lands, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China; College of Mathematics and System Sciences, Xinjiang University, Urumqi 830017, China
| | - Qi Liu
- State Key Laboratory of Desert and Oasis Ecology, Key Laboratory of Ecological Safety and Sustainable Development in Arid Lands, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China; Cele National Station of Observation & Research for Desert Grassland Ecosystem in Xinjiang, Cele 848300, China.
| | - Dongwei Gui
- State Key Laboratory of Desert and Oasis Ecology, Key Laboratory of Ecological Safety and Sustainable Development in Arid Lands, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China; Cele National Station of Observation & Research for Desert Grassland Ecosystem in Xinjiang, Cele 848300, China; University of Chinese Academy of Sciences, Beijing 101408, China
| | - Yunfei Liu
- State Key Laboratory of Desert and Oasis Ecology, Key Laboratory of Ecological Safety and Sustainable Development in Arid Lands, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China; Cele National Station of Observation & Research for Desert Grassland Ecosystem in Xinjiang, Cele 848300, China
| | - Xinlong Feng
- College of Mathematics and System Sciences, Xinjiang University, Urumqi 830017, China
| | - Jia Qu
- State Key Laboratory of Desert and Oasis Ecology, Key Laboratory of Ecological Safety and Sustainable Development in Arid Lands, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China; College of Mathematics and System Sciences, Xinjiang University, Urumqi 830017, China
| | - Jianping Zhao
- College of Mathematics and System Sciences, Xinjiang University, Urumqi 830017, China
| | - Guanghui Wei
- Xinjiang Tarim River Basin Management Bureau, Korla 841000, China
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Meierhofer MB, Johnson JS, Perez-Jimenez J, Ito F, Webela PW, Wiantoro S, Bernard E, Tanalgo KC, Hughes A, Cardoso P, Lilley T, Mammola S. Effective conservation of subterranean-roosting bats. CONSERVATION BIOLOGY : THE JOURNAL OF THE SOCIETY FOR CONSERVATION BIOLOGY 2024; 38:e14157. [PMID: 37504891 DOI: 10.1111/cobi.14157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 05/15/2023] [Accepted: 05/16/2023] [Indexed: 07/29/2023]
Abstract
Bats frequently inhabit caves and other subterranean habitats and play a critical role in subterranean food webs. With escalating threats to subterranean ecosystems, identifying the most effective measures to protect subterranean-roosting bats is critical. We conducted a meta-analysis to evaluate the effectiveness of conservation and management interventions for subterranean-roosting bats. We used network analyses to determine to what extent interventions for bats overlap those used for other subterranean taxa. We conducted our analyses with data extracted from 345 papers recommending a total of 910 conservation interventions. Gating of roost entrances was applied to preserve bat populations in 21 studies, but its effectiveness was unclear. Habitat restoration and disturbance reduction positively affected bat populations and bat behavior, respectively, in ≤4 studies. Decontamination was assessed in 2 studies and positively affected bat populations, particularly in studies focused on reducing fungal spores associated with white-nose syndrome in North America. Monitoring of bat populations as an effective conservation strategy was unclear and infrequently tested. Only 4% of bat studies simultaneously considered other subterranean organisms. However, effective interventions for bat conservation had similarities with all other organisms. If other subterranean organisms are considered when applying interventions to conserve bats, they might also benefit.
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Affiliation(s)
- Melissa B Meierhofer
- BatLab Finland, Finnish Museum of Natural History (LUOMUS), University of Helsinki, Helsinki, Finland
| | - Joseph S Johnson
- School of Information Technology, University of Cincinnati, Cincinnati, Ohio, USA
| | | | - Fernanda Ito
- BatLab Finland, Finnish Museum of Natural History (LUOMUS), University of Helsinki, Helsinki, Finland
- Laboratório de Ciência Aplicada à Conservação da Biodiversidade, Universidade Federal de Pernambuco, Recife, Brazil
| | - Paul W Webela
- Department of Forestry and Wildlife Management, Maasai Mara University, Narok, Kenya
| | - Sigit Wiantoro
- Museum Zoologicum Bogoriense, Research Center for Biosystematics & Evolution, National Research and Innovation Agency, Bogor, Indonesia
| | - Enrico Bernard
- Laboratório de Ciência Aplicada à Conservação da Biodiversidade, Universidade Federal de Pernambuco, Recife, Brazil
| | - Krizler C Tanalgo
- Ecology and Conservation Research Laboratory (Eco/Con Lab), Department of Biological Sciences, College of Science and Mathematics, University of Southern Mindanao, Cotabato, Philippines
| | - Alice Hughes
- School of Biological Sciences, University of Hong Kong, Hong Kong
- Center of Conservation Biology, Core Botanical Gardens, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Jinghong, China
| | - Pedro Cardoso
- Laboratory for Integrative Biodiversity Research (LIBRe), Finnish Museum of Natural History (LUOMUS), University of Helsinki, Helsinki, Finland
| | - Thomas Lilley
- BatLab Finland, Finnish Museum of Natural History (LUOMUS), University of Helsinki, Helsinki, Finland
| | - Stefano Mammola
- Laboratory for Integrative Biodiversity Research (LIBRe), Finnish Museum of Natural History (LUOMUS), University of Helsinki, Helsinki, Finland
- Molecular Ecology Group (MEG), Water Research Institute (IRSA), National Research Council (CNR), Verbania, Italy
- National Biodiversity Future Center, Palermo, Italy
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Panigrahi S, Maski P, Thondiyath A. Real-time biodiversity analysis using deep-learning algorithms on mobile robotic platforms. PeerJ Comput Sci 2023; 9:e1502. [PMID: 37705641 PMCID: PMC10495972 DOI: 10.7717/peerj-cs.1502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 07/04/2023] [Indexed: 09/15/2023]
Abstract
Ecological biodiversity is declining at an unprecedented rate. To combat such irreversible changes in natural ecosystems, biodiversity conservation initiatives are being conducted globally. However, the lack of a feasible methodology to quantify biodiversity in real-time and investigate population dynamics in spatiotemporal scales prevents the use of ecological data in environmental planning. Traditionally, ecological studies rely on the census of an animal population by the "capture, mark and recapture" technique. In this technique, human field workers manually count, tag and observe tagged individuals, making it time-consuming, expensive, and cumbersome to patrol the entire area. Recent research has also demonstrated the potential for inexpensive and accessible sensors for ecological data monitoring. However, stationary sensors collect localised data which is highly specific on the placement of the setup. In this research, we propose the methodology for biodiversity monitoring utilising state-of-the-art deep learning (DL) methods operating in real-time on sample payloads of mobile robots. Such trained DL algorithms demonstrate a mean average precision (mAP) of 90.51% in an average inference time of 67.62 milliseconds within 6,000 training epochs. We claim that the use of such mobile platform setups inferring real-time ecological data can help us achieve our goal of quick and effective biodiversity surveys. An experimental test payload is fabricated, and online as well as offline field surveys are conducted, validating the proposed methodology for species identification that can be further extended to geo-localisation of flora and fauna in any ecosystem.
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Affiliation(s)
- Siddhant Panigrahi
- Department of Engineering Design, Indian Institute of Technology Madras, Chennai, Tamil Nadu, India
| | - Prajwal Maski
- Department of Engineering Design, Indian Institute of Technology Madras, Chennai, Tamil Nadu, India
| | - Asokan Thondiyath
- Department of Engineering Design, Indian Institute of Technology Madras, Chennai, Tamil Nadu, India
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Ito F, Lilley T, Twort VG, Bernard E. High genetic connectivity among large populations of Pteronotus gymnonotus in bat caves in Brazil and its implications for conservation. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.934633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Bat caves in the Neotropical region harbor exceptional bat populations (> 100,000 individuals). These populations play a wider role in ecological interactions, are vulnerable due to their restriction to caves, and have a disproportionate conservation value. Current knowledge of bat caves in Brazil is still small. However, systematic monitoring of some bat caves in northeastern Brazil shows that they experience strong population fluctuations over short periods of time, suggesting large-scale movements between roosts and a much broader use of the landscape than previously considered. Spatio-temporal reproductive connectivity between distant populations would change our understanding of the use of roosts among bat species in Brazil, and important gaps in knowledge of long-distance bat movements in the country would be filled. Here, we used ddRADseq data to analyze the genetic structure of Pteronotus gymnonotus across nine bat caves over 700 km. Our results indicate the lack of a clear geographic structure with gene flow among all the caves analyzed, suggesting that P. gymnonotus uses a network of bat caves geographically segregated hundreds of kilometers apart. Facing strong anthropogenic impacts and an underrepresentation of caves in conservation action plans worldwide, the genetic connectivity demonstrated here confirms that bat caves are priority sites for bat and speleological conservation in Brazil and elsewhere. Moreover, our results demonstrate a warning call: the applied aspects of the environmental licensing process of the mining sector and its impact must be reviewed, not only in Brazil, but wherever this licensing process affects caves having exceptional bat populations.
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Corcoran AJ. Sing or Jam? Density-Dependent Food Competition Strategies in Mexican Free-Tailed Bats (Tadarida brasiliensis). Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.877579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Organisms compete for food in many ways, but it is often difficult to know why they use certain competition strategies over others. Bats compete for food either through aggression coupled with food-claiming signals or by actively interfering with a competitor’s sensory processing during prey pursuit (i.e., jamming). It is not known why these different behaviors are exhibited. I studied food competition between Mexican free-tailed bats (Tadarida brasiliensis) at foraging sites in Arizona and New Mexico using passive acoustic recording, insect sampling and 3-D infrared videography with or without supplemental lighting that concentrated prey. Bat activity was quantified by the number of recorded echolocation calls, while feeding behavior was indicated by feeding buzzes. Two competitive behaviors were observed—song, which was produced by bats chasing conspecifics, and sinFM calls, which jam echolocation of competitors pursuing prey. Song production was most common when few bats were present and feeding at low rates. In contrast, jamming signals were most common with many bats present and feeding at high rates. Supplemental lighting increased the numbers of bats, feeding buzzes and sinFM calls, but not song. These results indicate that bats employ different strategies—singing and chasing competitors at low bat densities but jamming competitors at high bat densities. Food claiming signals (song) may only be effective with few competitors present, whereas jamming can be effective with many bats at a foraging site. Multiple competition strategies appear to have evolved in bats that are used under different densities of competitors.
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Darras K, Yusti E, Knorr A, Huang JCC, Kartono AP, Ilham. Sampling flying bats with thermal and near-infrared imaging and ultrasound recording: hardware and workflow for bat point counts. F1000Res 2022; 10:189. [PMID: 35436082 PMCID: PMC8987345 DOI: 10.12688/f1000research.51195.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/17/2022] [Indexed: 11/20/2022] Open
Abstract
Bat communities can usually only be comprehensively monitored by combining ultrasound recording and trapping techniques. Here, we propose bat point counts, a novel, single method to sample all flying bats. We designed a sampling rig that combines a thermal scope to detect flying bats and their flight patterns, an ultrasound recorder to identify echolocating bat calls, and a near-infrared camera and LED illuminator to photograph bat morphology. We evaluated the usefulness of the flight pattern information, echolocation call recordings, and near-infrared photographs produced by our sampling rig to determine a workflow to process these heterogenous data types. We present a conservative workflow to enable taxonomic discrimination and identification of bat detections. Our sampling rig and workflow allowed us to detect both echolocating and non-echolocating bats and we could assign 84% of the detections to a guild. Subsequent identification can be carried out with established methods such as taxonomic keys and call libraries, based on the visible morphological features and echolocation calls. Currently, a higher near-infrared picture quality is required to resolve more detailed diagnostic morphology, but there is considerable potential to extract more information with higher-intensity illumination. This is the first proof-of-concept for bat point counts, a method that can passively sample all flying bats in their natural environment.
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Affiliation(s)
- Kevin Darras
- Agroecology, University of Göttingen, Göttingen, Niedersachsen, 37077, Germany
| | - Ellena Yusti
- CRC 990 - EFForTS, University of Jambi, Jambi, 36361, Indonesia
| | - Andreas Knorr
- Mess-, Steuerungs-, und Regeltechnik, University of Göttingen, Göttingen, Niedersachsen, 37077, Germany
| | - Joe Chun-Chia Huang
- Division of Botanical Gardens, Taiwan Forestry Research Institute, Taipei, 10079, Taiwan
| | - Agus Priyono Kartono
- Department of Forest Resources Conservation and Ecotourism, IPB University, Bogor, 16680, Indonesia
| | - Ilham
- CRC 990 - EFForTS, University of Jambi, Jambi, 36361, Indonesia
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Tuia D, Kellenberger B, Beery S, Costelloe BR, Zuffi S, Risse B, Mathis A, Mathis MW, van Langevelde F, Burghardt T, Kays R, Klinck H, Wikelski M, Couzin ID, van Horn G, Crofoot MC, Stewart CV, Berger-Wolf T. Perspectives in machine learning for wildlife conservation. Nat Commun 2022; 13:792. [PMID: 35140206 PMCID: PMC8828720 DOI: 10.1038/s41467-022-27980-y] [Citation(s) in RCA: 74] [Impact Index Per Article: 37.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Accepted: 12/08/2021] [Indexed: 11/08/2022] Open
Abstract
Inexpensive and accessible sensors are accelerating data acquisition in animal ecology. These technologies hold great potential for large-scale ecological understanding, but are limited by current processing approaches which inefficiently distill data into relevant information. We argue that animal ecologists can capitalize on large datasets generated by modern sensors by combining machine learning approaches with domain knowledge. Incorporating machine learning into ecological workflows could improve inputs for ecological models and lead to integrated hybrid modeling tools. This approach will require close interdisciplinary collaboration to ensure the quality of novel approaches and train a new generation of data scientists in ecology and conservation.
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Affiliation(s)
- Devis Tuia
- School of Architecture, Civil and Environmental Engineering, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
| | - Benjamin Kellenberger
- School of Architecture, Civil and Environmental Engineering, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Sara Beery
- Department of Computing and Mathematical Sciences, California Institute of Technology (Caltech), Pasadena, CA, USA
| | - Blair R Costelloe
- Max Planck Institute of Animal Behavior, Radolfzell, Germany
- Centre for the Advanced Study of Collective Behaviour, University of Konstanz, Konstanz, Germany
- Department of Biology, University of Konstanz, Konstanz, Germany
| | - Silvia Zuffi
- Institute for Applied Mathematics and Information Technologies, IMATI-CNR, Pavia, Italy
| | - Benjamin Risse
- Computer Science Department, University of Münster, Münster, Germany
| | - Alexander Mathis
- School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Mackenzie W Mathis
- School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | | | - Tilo Burghardt
- Computer Science Department, University of Bristol, Bristol, UK
| | - Roland Kays
- Department of Forestry and Environmental Resources, North Carolina State University, Raleigh, NC, USA
- North Carolina Museum of Natural Sciences, Raleigh, NC, USA
| | - Holger Klinck
- Cornell Lab of Ornithology, Cornell University, Ithaca, NY, USA
| | - Martin Wikelski
- Max Planck Institute of Animal Behavior, Radolfzell, Germany
- Centre for the Advanced Study of Collective Behaviour, University of Konstanz, Konstanz, Germany
| | - Iain D Couzin
- Max Planck Institute of Animal Behavior, Radolfzell, Germany
- Centre for the Advanced Study of Collective Behaviour, University of Konstanz, Konstanz, Germany
- Department of Biology, University of Konstanz, Konstanz, Germany
| | - Grant van Horn
- Cornell Lab of Ornithology, Cornell University, Ithaca, NY, USA
| | - Margaret C Crofoot
- Max Planck Institute of Animal Behavior, Radolfzell, Germany
- Centre for the Advanced Study of Collective Behaviour, University of Konstanz, Konstanz, Germany
- Department of Biology, University of Konstanz, Konstanz, Germany
| | - Charles V Stewart
- Department of Computer Science, Rensselaer Polytechnic Institute, Troy, NY, USA
| | - Tanya Berger-Wolf
- Translational Data Analytics Institute, The Ohio State University, Columbus, OH, USA
- Departments of Computer Science and Engineering; Electrical and Computer Engineering; Evolution, Ecology, and Organismal Biology, The Ohio State University, Columbus, OH, USA
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Tosa MI, Dziedzic EH, Appel CL, Urbina J, Massey A, Ruprecht J, Eriksson CE, Dolliver JE, Lesmeister DB, Betts MG, Peres CA, Levi T. The Rapid Rise of Next-Generation Natural History. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.698131] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Many ecologists have lamented the demise of natural history and have attributed this decline to a misguided view that natural history is outdated and unscientific. Although there is a perception that the focus in ecology and conservation have shifted away from descriptive natural history research and training toward hypothetico-deductive research, we argue that natural history has entered a new phase that we call “next-generation natural history.” This renaissance of natural history is characterized by technological and statistical advances that aid in collecting detailed observations systematically over broad spatial and temporal extents. The technological advances that have increased exponentially in the last decade include electronic sensors such as camera-traps and acoustic recorders, aircraft- and satellite-based remote sensing, animal-borne biologgers, genetics and genomics methods, and community science programs. Advances in statistics and computation have aided in analyzing a growing quantity of observations to reveal patterns in nature. These robust next-generation natural history datasets have transformed the anecdotal perception of natural history observations into systematically collected observations that collectively constitute the foundation for hypothetico-deductive research and can be leveraged and applied to conservation and management. These advances are encouraging scientists to conduct and embrace detailed descriptions of nature that remain a critically important component of the scientific endeavor. Finally, these next-generation natural history observations are engaging scientists and non-scientists alike with new documentations of the wonders of nature. Thus, we celebrate next-generation natural history for encouraging people to experience nature directly.
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9
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Richardson CS, Hood W, Allen L, Hristov N, Ineson K, Reichard J, McCracken G, Kurta A, Reynolds DS. Thomas H. Kunz. Physiol Biochem Zool 2021. [DOI: 10.1086/714937] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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10
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Monthly fluctuation of colony size and composition of the free-tailed bat Tadarida brasiliensis in the southernmost roost of Mexico. MAMMAL RES 2021. [DOI: 10.1007/s13364-021-00559-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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11
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Pocknee CA, Lahoz-Monfort JJ, Martin RW, Wintle BA. Cost-effectiveness of thermal imaging for monitoring a cryptic arboreal mammal. WILDLIFE RESEARCH 2021. [DOI: 10.1071/wr20120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
ContextThe development of reliable and cost-efficient survey techniques is key to the monitoring of all wildlife. One group of species that presents particular challenges for monitoring is the arboreal mammals. Traditional techniques for detecting these species often yield low detection probabilities (detectability) and are time-consuming, suggesting the potential for novel methods to enhance our understanding of their distribution, abundance and population trajectories. One technique that has been shown to increase detectability in a range of terrestrial species is thermal imaging, although it has rarely been applied to arboreal species. The true conservation status of Lumholtz’s tree-kangaroo (Dendrolagus lumholtzi) is uncertain because of low detectability under typical survey techniques, and a more suitable method is required to enable effective monitoring of the species, making it an ideal candidate for the present study.
AimsWe aimed to compare the success and cost-effectiveness of surveys utilising thermal imaging with two traditional methods, namely, spotlighting and daytime surveys, so as to optimise monitoring of D. lumholtzi.
MethodsWe conducted surveys at 10 sites in Queensland (Australia) where D. lumholtzi was known to occur, by using each method, and modelled both the detectability of D. lumholtzi and the cost-effectiveness of each technique.
Key resultsDetectability of D. lumholtzi was significantly higher with the use of thermal imaging than it was with the other survey methods, and thermal detection is more cost-effective. In average survey conditions with a trained observer, the single-visit estimated detectability of D. lumholtzi was 0.28 [0.04, 0.79] in a transect through rainforest, by using thermal imaging. Using only spotlights, the detection probability was 0.03 [0, 0.28] under the same conditions.
ConclusionsThese results show that incorporating thermal technology into monitoring surveys will greatly increase detection probability for D. lumholtzi, a cryptic arboreal mammal.
ImplicationsOur study highlighted the potential utility of thermal detection in monitoring difficult-to-detect species in complex habitats, including species that exist mainly in dense forest canopy.
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Shaffer I, Abaid N. Transfer Entropy Analysis of Interactions between Bats Using Position and Echolocation Data. ENTROPY (BASEL, SWITZERLAND) 2020; 22:E1176. [PMID: 33286944 PMCID: PMC7597347 DOI: 10.3390/e22101176] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 10/09/2020] [Accepted: 10/12/2020] [Indexed: 06/12/2023]
Abstract
Many animal species, including many species of bats, exhibit collective behavior where groups of individuals coordinate their motion. Bats are unique among these animals in that they use the active sensing mechanism of echolocation as their primary means of navigation. Due to their use of echolocation in large groups, bats run the risk of signal interference from sonar jamming. However, several species of bats have developed strategies to prevent interference, which may lead to different behavior when flying with conspecifics than when flying alone. This study seeks to explore the role of this acoustic sensing on the behavior of bat pairs flying together. Field data from a maternity colony of gray bats (Myotis grisescens) were collected using an array of cameras and microphones. These data were analyzed using the information theoretic measure of transfer entropy in order to quantify the interaction between pairs of bats and to determine the effect echolocation calls have on this interaction. This study expands on previous work that only computed information theoretic measures on the 3D position of bats without echolocation calls or that looked at the echolocation calls without using information theoretic analyses. Results show that there is evidence of information transfer between bats flying in pairs when time series for the speed of the bats and their turning behavior are used in the analysis. Unidirectional information transfer was found in some subsets of the data which could be evidence of a leader-follower interaction.
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Affiliation(s)
- Irena Shaffer
- Engineering Mechanics Program, Virginia Tech, Blacksburg, VA 24061, USA;
| | - Nicole Abaid
- Department of Mathematics, Virginia Tech, Blacksburg, VA 24061, USA
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13
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Winterl A, Richter S, Houstin A, Nesterova AP, Bonadonna F, Schneider W, Fabry B, Le Bohec C, Zitterbart DP. micrObs - A customizable time-lapse camera for ecological studies. HARDWAREX 2020; 8:e00134. [PMID: 35498253 PMCID: PMC9041239 DOI: 10.1016/j.ohx.2020.e00134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 08/13/2020] [Accepted: 08/15/2020] [Indexed: 06/14/2023]
Abstract
Camera traps for motion-triggered or continuous time-lapse recordings are readily available on the market. For demanding applications in ecology and environmental sciences, however, commercial systems often lack flexibility to freely adjust recording time intervals, suffer from mechanical component wear, and can be difficult to combine with auxiliary sensors such as GPS, weather stations, or light sensors. We present a robust time-lapse camera system that has been operating continuously since 2013 under the harsh climatic conditions of the Antarctic and Subantarctic regions. Thus far, we have recorded over one million images with individual cameras. The system consumes 122 mW of power in standby mode and captures up to 200,000 high-resolution (16 MPix) images without maintenance such as battery or image memory replacement. It offers time-lapse intervals between 2 s and 1 h, low-light or night-time power saving, and data logging capabilities for additional inputs such as GPS and weather data.
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Affiliation(s)
- Alexander Winterl
- Department of Physics, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
- Department of Applied Ocean Physics and Engineering, Woods Hole Oceanographic Institution, Woods Hole, USA
| | - Sebastian Richter
- Department of Physics, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
- Department of Applied Ocean Physics and Engineering, Woods Hole Oceanographic Institution, Woods Hole, USA
| | - Aymeric Houstin
- Centre Scientifique de Monaco, Département de Biologie Polaire, Monaco, Monaco
- Université de Strasbourg, CNRS, IPHC, UMR 7178, Strasbourg, France
| | - Anna P. Nesterova
- INRAE, CNRS, Université de Tours, PRC, UMR 7247, Nouzilly, France
- CEFE, Univ Montpellier, CNRS, Univ Paul Valéry Montpellier 3, EPHE, IRD, Montpellier, France
| | - Francesco Bonadonna
- CEFE, Univ Montpellier, CNRS, Univ Paul Valéry Montpellier 3, EPHE, IRD, Montpellier, France
| | - Werner Schneider
- Department of Physics, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | - Ben Fabry
- Department of Physics, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
| | - Céline Le Bohec
- Centre Scientifique de Monaco, Département de Biologie Polaire, Monaco, Monaco
- Université de Strasbourg, CNRS, IPHC, UMR 7178, Strasbourg, France
| | - Daniel P. Zitterbart
- Department of Physics, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
- Department of Applied Ocean Physics and Engineering, Woods Hole Oceanographic Institution, Woods Hole, USA
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Revilla-Martín N, Budinski I, Puig-Montserrat X, Flaquer C, López-Baucells A. Monitoring cave-dwelling bats using remote passive acoustic detectors: a new approach for cave monitoring. BIOACOUSTICS 2020. [DOI: 10.1080/09524622.2020.1816492] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Natalia Revilla-Martín
- Biodiversity and Bioindicators (BiBIO), Natural Sciences Museum of Granollers, Granollers, Spain
- University of Barcelona, Barcelona, Spain
| | - Ivana Budinski
- Biodiversity and Bioindicators (BiBIO), Natural Sciences Museum of Granollers, Granollers, Spain
- Department of Genetic Research, Institute for Biological Research “Siniša Stanković” - National Institute of Republic of Serbia, University of Belgrade, Belgrade, Serbia
| | - Xavier Puig-Montserrat
- Biodiversity and Bioindicators (BiBIO), Natural Sciences Museum of Granollers, Granollers, Spain
- Galanthus Association, Celrà, Spain
| | - Carles Flaquer
- Biodiversity and Bioindicators (BiBIO), Natural Sciences Museum of Granollers, Granollers, Spain
| | - Adrià López-Baucells
- Biodiversity and Bioindicators (BiBIO), Natural Sciences Museum of Granollers, Granollers, Spain
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15
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Zuercher ME, Monson TA, Dvoretzky RR, Ravindramurthy S, Hlusko LJ. Dental Variation in Megabats (Chiroptera: Pteropodidae): Tooth Metrics Correlate with Body Size and Tooth Proportions Reflect Phylogeny. J MAMM EVOL 2020. [DOI: 10.1007/s10914-020-09508-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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16
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Using Thermal Infrared Cameras to Detect Avian Chicks at Various Distances and Vegetative Coverages. JOURNAL OF FISH AND WILDLIFE MANAGEMENT 2020. [DOI: 10.3996/072019-jfwm-062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Abstract
Population monitoring of nesting waterbirds often involves frequent entries into the colony, but alternative methods such as local remotely sensed thermal imaging may help reduce disturbance while providing a cost-effective way to survey breeding populations. Such an approach can have high initial costs, however, which may have reduced the number of studies investigating functionality of paired thermal infrared camera and small unmanned aerial systems. Here, we take the first step of exploring the ability of two thermal infrared cameras to detect an avian chick under varying vegetative cover and distances, preceding field-mounting applications on a small unmanned aerial system. We created seven “bioboxes” to simulate a range of natural vegetation types and densities for a globally important colonial ground-nesting waterbird species, the common tern Sterna hirundo. We placed a juvenile chicken Gallus gallus (surrogate for the locally endangered common tern) in each box, and we tested two market-accessible infrared cameras (produced by FLIR Systems and Infrared Cameras, Inc.) at five elevations using a stationary boom (maximum height = 12 m). We applied computer-based digital thresholding to collected images, identifying pixels meeting one of seven threshold values. The chick was visible from at least one threshold value in 19 and 31 of 35 processed by the FLIR Systems and Infrared Cameras, respectively. Percentage of the chick identified across thresholds was generally highest at lower threshold values and elevations and decreased as elevation and threshold increased; however, the relative importance of each variable changed dramatically across bioboxes and camera types. Ability to detect a chick from processed images generally decreased with increasing elevation, and although we made no quantitative comparisons among boxes, detectability appeared greatest in images from both cameras when little or no vegetation was present. Interestingly, no single threshold value was best for all bioboxes. We observed notable differences between cameras including visual resolution of detected temperature differentials and image processing speed. Results of this controlled study show promise for the use of thermal infrared systems for detecting cryptic species in vegetation. Future research should work to combine thermal infrared and visual sensors with small unmanned aerial systems to test applicability in a mobile field application.
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Sánchez-Losada M, Mancina CA. Diet Segregation between Sexes by a Gregarious Greater Antillean Bat, Phyllonycteris poeyi (Chiroptera: Phyllostomidae). ACTA CHIROPTEROLOGICA 2020. [DOI: 10.3161/15081109acc2019.21.2.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Margarita Sánchez-Losada
- Centro Oriental de Ecosistemas y Biodiversida jambos, José A. Saco, No. 601, esquina a Barnada. Santiago de Cuba, Cuba
| | - Carlos A. Mancina
- Instituto de Ecología y Sistemática, Carretera Varona # 11835, Reparto Parajón, La Habana, Cuba
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Otálora-Ardila A, Torres JM, Barbier E, Pimentel NT, Barbosa Leal ES, Bernard E. Thermally-Assisted Monitoring of Bat Abundance in an Exceptional Cave in Brazil's Caatinga Drylands. ACTA CHIROPTEROLOGICA 2020. [DOI: 10.3161/15081109acc2019.21.2.016] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Aída Otálora-Ardila
- Laboratório de Ciência Aplicada à Conservação da Biodiversidade, Departamento de Zoologia, Universidade Federal de Pernambuco, Recife, Pernambuco, Brazil 50670-901
| | - Jaire Marinho Torres
- Laboratório de Ciência Aplicada à Conservação da Biodiversidade, Departamento de Zoologia, Universidade Federal de Pernambuco, Recife, Pernambuco, Brazil 50670-901
| | - Eder Barbier
- Laboratório de Ciência Aplicada à Conservação da Biodiversidade, Departamento de Zoologia, Universidade Federal de Pernambuco, Recife, Pernambuco, Brazil 50670-901
| | - Narjara Tércia Pimentel
- Laboratório de Ciência Aplicada à Conservação da Biodiversidade, Departamento de Zoologia, Universidade Federal de Pernambuco, Recife, Pernambuco, Brazil 50670-901
| | - Edson S. Barbosa Leal
- Laboratório de Ciência Aplicada à Conservação da Biodiversidade, Departamento de Zoologia, Universidade Federal de Pernambuco, Recife, Pernambuco, Brazil 50670-901
| | - Enrico Bernard
- Laboratório de Ciência Aplicada à Conservação da Biodiversidade, Departamento de Zoologia, Universidade Federal de Pernambuco, Recife, Pernambuco, Brazil 50670-901
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Hristov NI, Nikolaidis D, Hubel TY, Allen LC. Estimating Overwintering Monarch Butterfly Populations Using Terrestrial LiDAR Scanning. Front Ecol Evol 2019. [DOI: 10.3389/fevo.2019.00266] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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20
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Using weather radar to monitor the number, timing and directions of flying-foxes emerging from their roosts. Sci Rep 2019; 9:10222. [PMID: 31308411 PMCID: PMC6629676 DOI: 10.1038/s41598-019-46549-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Accepted: 06/27/2019] [Indexed: 11/08/2022] Open
Abstract
Knowledge of species' population trends is crucial when planning for conservation and management; however, this information can be difficult to obtain for extremely mobile species such as flying-foxes (Pteropus spp.; Chiroptera, Pteropodidae). In mainland Australia, flying-foxes are of particular management concern due their involvement in human-wildlife conflict, and their role as vectors of zoonotic diseases; and two species, the grey-headed flying-fox (Pteropus poliocephalus) and the spectacled flying-fox (P. conspicillatus), are currently threatened with extinction. Here we demonstrate that archival weather radar data over a period of ten years can be used to monitor a large colony of grey-headed flying-foxes near Melbourne. We show that radar estimates of colony size closely match those derived from traditional counting methods. Moreover, we show that radar data can be used to determine the timing and departure direction of flying-foxes emerging from the roost. Finally, we show that radar observations of flying-foxes can be used to identify signals of important ecological events, such as mass flowering and extreme heat events, and can inform human activities, e.g. the safe operation of airports and windfarms. As such, radar represents an extremely promising tool for the conservation and management of vulnerable flying-fox populations and for managing human interactions with these ecologically-important mammals.
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Hernández-Jerez A, Adriaanse P, Aldrich A, Berny P, Coja T, Duquesne S, Gimsing AL, Marina M, Millet M, Pelkonen O, Pieper S, Tiktak A, Tzoulaki I, Widenfalk A, Wolterink G, Russo D, Streissl F, Topping C. Scientific statement on the coverage of bats by the current pesticide risk assessment for birds and mammals. EFSA J 2019; 17:e05758. [PMID: 32626374 PMCID: PMC7009170 DOI: 10.2903/j.efsa.2019.5758] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Bats are an important group of mammals, frequently foraging in farmland and potentially exposed to pesticides. This statement considers whether the current risk assessment performed for birds and ground dwelling mammals exposed to pesticides is also protective of bats. Three main issues were addressed. Firstly, whether bats are toxicologically more or less sensitive than the most sensitive birds and mammals. Secondly, whether oral exposure of bats to pesticides is greater or lower than in ground dwelling mammals and birds. Thirdly, whether there are other important exposure routes relevant to bats. A large variation in toxicological sensitivity and no relationship between sensitivity of bats and bird or mammal test-species to pesticides could be found. In addition, bats have unique traits, such as echolocation and torpor which can be adversely affected by exposure to pesticides and which are not covered by the endpoints currently selected for wild mammal risk assessment. The current exposure assessment methodology was used for oral exposure and adapted to bats using bat-specific parameters. For oral exposure, it was concluded that for most standard risk assessment scenarios the current approach did not cover exposure of bats to pesticide residues in food. Calculations of potential dermal exposure for bats foraging during spraying operations suggest that this may be a very important exposure route. Dermal routes of exposure should be combined with inhalation and oral exposure. Based on the evidence compiled, the Panel concludes that bats are not adequately covered by the current risk assessment approach, and that there is a need to develop a bat-specific risk assessment scheme. In general, there was scarcity of data to assess the risks for bat exposed to pesticides. Recommendations for research are made, including identification of alternatives to laboratory testing of bats to assess toxicological effects.
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Rogers EJ, Sommers AS, McGuire LP. Seasonal Dynamics of Lipid Metabolism and Energy Storage in the Brazilian Free-Tailed Bat. Physiol Biochem Zool 2019; 92:386-395. [DOI: 10.1086/704107] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Migration and reproduction are associated with similar degrees of phenotypic flexibility in an insectivorous bat. Oecologia 2019; 190:747-755. [DOI: 10.1007/s00442-019-04449-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Accepted: 06/25/2019] [Indexed: 10/26/2022]
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Kloepper LN, Branstetter BK. The effect of jamming stimuli on the echolocation behavior of the bottlenose dolphin, Tursiops truncatus. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2019; 145:1341. [PMID: 31067932 DOI: 10.1121/1.5093636] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Accepted: 02/22/2019] [Indexed: 06/09/2023]
Abstract
Echolocating bats and odontocetes face the potential challenge of acoustic interference from neighbors, or sonar jamming. To counter this, many bat species have adapted jamming avoidance strategies to improve signal detection, but any such avoidance strategies in dolphins is unknown. This study provides an investigation into whether dolphins modify echolocation behavior during jamming scenarios. Recorded echolocation clicks were projected at different click repetition rates and at different aspect angles relative to two dolphins' heads while each dolphin was performing a target detection task. Changes in the timing, amplitude, and frequency of structure of the dolphin's emitted signals were compared to determine if and how dolphins modify echolocation when faced with potentially interfering conspecific echolocation signals. The results indicate that both dolphins demonstrated different responses when faced with jamming scenarios, which may reflect optimal strategies according to individual auditory perception abilities.
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Affiliation(s)
- Laura N Kloepper
- Department of Biology, Saint Mary's College, Notre Dame, Indiana 46556, USA
| | - Brian K Branstetter
- National Marine Mammal Foundation, 2240 Shelter Island Drive, #200, San Diego, California 92106, USA
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Harrap MJM, Hempel de Ibarra N, Whitney HM, Rands SA. Reporting of thermography parameters in biology: a systematic review of thermal imaging literature. ROYAL SOCIETY OPEN SCIENCE 2018; 5:181281. [PMID: 30662737 PMCID: PMC6304129 DOI: 10.1098/rsos.181281] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Accepted: 11/09/2018] [Indexed: 05/25/2023]
Abstract
Infrared (IR) thermography, where temperature measurements are made with IR cameras, has proven to be a very useful and widely used tool in biological science. Several thermography parameters are critical to the proper operation of thermal cameras and the accuracy of measurements, and these must usually be provided to the camera. Failure to account for these parameters may lead to less accurate measurements. Furthermore, the failure to provide information of parameter choices in reports may compromise appraisal of accuracy and replicate studies. In this review, we investigate how well biologists report thermography parameters. This is done through a systematic review of biological thermography literature that included articles published between years 2007 and 2017. We found that in primary biological thermography papers, which make some kind of quantitative temperature measurement, 48% fail to report values used for emissivity (an object's capacity to emit thermal radiation relative to a black body radiator), which is the minimum level of reporting that should take place. This finding highlights the need for life scientists to take into account and report key parameter information when carrying out thermography, in the future.
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Affiliation(s)
| | - Natalie Hempel de Ibarra
- Centre for Research in Animal Behaviour, School of Psychology, University of Exeter, Exeter EX4 4QG, UK
| | - Heather M. Whitney
- School of Biological Sciences, University of Bristol, Bristol BS8 1TQ, UK
| | - Sean A. Rands
- School of Biological Sciences, University of Bristol, Bristol BS8 1TQ, UK
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Haefele MA, Loomis JB, Merideth R, Lien A, Semmens DJ, Dubovsky J, Wiederholt R, Thogmartin WE, Huang TK, McCracken G, Medellin RA, Diffendorfer JE, López-Hoffman L. Willingness to Pay for Conservation of Transborder Migratory Species: A Case Study of the Mexican Free-Tailed Bat in the United States and Mexico. ENVIRONMENTAL MANAGEMENT 2018; 62:229-240. [PMID: 29732478 DOI: 10.1007/s00267-018-1046-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 04/12/2018] [Indexed: 06/08/2023]
Abstract
We estimated U.S. and Mexican citizens' willingness to pay (WTP) for protecting habitat for a transborder migratory species, the Mexican free-tailed bat (Tadarida brasiliensis mexicana), using the contingent valuation method. Few contingent valuation surveys have evaluated whether households in one country would pay to protect habitat in another country. This study addresses that gap. In our study, Mexican respondents were asked about their WTP for conservation of Mexican free-tailed bat habitat in Mexico and in the United States. Similarly, U.S. respondents were asked about their WTP for conservation in the United States and in Mexico. U.S. households would pay $30 annually to protect habitat in the United States and $24 annually to protect habitat in Mexico. Mexican households would pay $8 annually to protect habitat in Mexico and $5 annually to protect habitat in the United States. In both countries, these WTP amounts rose significantly for increasing the size of the bat population rather than simply stabilizing the current bat population. The ratio of Mexican household WTP relative to U.S. household WTP is nearly identical to that of Mexican household income relative to U.S. household income. This suggests that the perceived economic benefits received from the bats is similar in Mexico and the United States, and that scaling WTP by relative income in international benefit transfer may be plausible.
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Affiliation(s)
- Michelle A Haefele
- Department of Agricultural and Resource Economics, Colorado State University, B320 Clark Building, Fort Collins, CO, 80523-1172, USA
| | - John B Loomis
- Department of Agricultural and Resource Economics, Colorado State University, B320 Clark Building, Fort Collins, CO, 80523-1172, USA.
| | - Robert Merideth
- Udall Center for Studies in Public Policy, The University of Arizona, Tucson, AZ, 85719, USA
| | - Aaron Lien
- School of Natural Resources and the Environment, The University of Arizona, Tucson, AZ, 85721, USA
| | - Darius J Semmens
- U.S. Geological Survey, Geosciences and Environmental Change Science Center, P.O. Box 25046, MS-980, Denver, CO, 80225-0046, USA
| | - James Dubovsky
- U.S. Fish and Wildlife Service, Division of Migratory Bird Management, 755 Parfet Street Suite 235, Lakewood, CO, 80215, USA
| | - Ruscena Wiederholt
- Everglades Foundation, 18001 Old Cutler Road, Suite 625, Palmetto Bay, FL, 33157, USA
| | - Wayne E Thogmartin
- U.S. Geological Survey, Upper Midwest Environmental Sciences Center, 2630 Fanta Reed Road, La Crosse, WI, 54603, USA
| | - Ta-Ken Huang
- School of Natural Resources and the Environment, The University of Arizona, Tucson, AZ, 85721, USA
| | - Gary McCracken
- Department of Ecology and Evolutionary Biology, University of Tennessee, 569 Dabney Hall, Knoxville, TN, 37996, USA
| | - Rodrigo A Medellin
- Insituto de Ecologia, UNAM, Ciudad Universitaria, Ap. Postal 70-275, 04510, Mexico City, Mexico
| | - James E Diffendorfer
- U.S. Geological Survey, Geosciences and Environmental Change Science Center, P.O. Box 25046, MS-980, Denver, CO, 80225-0046, USA
| | - Laura López-Hoffman
- Udall Center for Studies in Public Policy, The University of Arizona, Tucson, AZ, 85719, USA
- School of Natural Resources and the Environment, The University of Arizona, Tucson, AZ, 85721, USA
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Stepanian PM, Wainwright CE. Ongoing changes in migration phenology and winter residency at Bracken Bat Cave. GLOBAL CHANGE BIOLOGY 2018; 24:3266-3275. [PMID: 29442413 DOI: 10.1111/gcb.14051] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Accepted: 01/04/2018] [Indexed: 06/08/2023]
Abstract
Bats play an important role in agroecology and are effective bioindicators of environmental conditions, but little is known about their fundamental migration ecology, much less how these systems are responding to global change. Some of the world's largest bat populations occur during the summer in the south-central United States, when millions of pregnant females migrate from lower latitudes to give birth in communal maternity colonies. Despite a relatively large volume of research into these colonies, many fundamental questions regarding their abundance-including their intra- and interseasonal variability-remain unanswered, and even estimating the size of individual populations has been a long-running challenge. Overall, monitoring these bat populations at high temporal resolution (e.g., nightly) and across long time spans (e.g., decades) has been impossible. Here, we show 22 continuous years of nightly population counts at Bracken Cave, a large bat colony in south-central Texas, enabling the first climate-scale phenological analysis. Using quantitative radar monitoring, we found that spring migration and the summer reproductive cycle have advanced by approximately 2 weeks over the study period. Furthermore, we quantify the ongoing growth of a newly-established overwintering population that indicates a system-wide response to changing environmental conditions. Our observations reveal behavioral plasticity in bats' ability to adapt to changing resource availability, and provide the first long-term quantification of their response to a changing climate. As aerial insectivores, these changes in bat phenology and propensity for overwintering indicate probable shifts in prey availability, with clear implications for pest management across wider regional agrisystems.
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Affiliation(s)
- Phillip M Stepanian
- Computational and Analytical Sciences Department, Rothamsted Research, Harpenden, UK
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Krauel J, Ratcliffe J, Westbrook J, McCracken G. Brazilian free-tailed bats (Tadarida brasiliensis) adjust foraging behaviour in response to migratory moths. CAN J ZOOL 2018. [DOI: 10.1139/cjz-2017-0284] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Insect migrations represent large movements of resources across a landscape, which are attractive to predators capable of detecting and catching them. Brazilian free-tailed bats (Tadarida brasiliensis (I. Geoffroy, 1824)) consume migratory noctuid moths, which concentrate in favourable winds resulting in aggregations of prey that attract bats hundreds of metres above ground. Although T. brasiliensis are known to feed on these aggregations of migratory moths, changes in their foraging behaviours have not been linked to moth migration events. We investigated possible shifts in the bats’ foraging behaviours when moths are migrating with respect to altitude and moth abundance. We recorded 1104 echolocation call passes of T. brasiliensis at ground level and at altitudes of ∼100 and ∼200 m above ground level. We found proportionally more bat activity at higher altitudes when migratory moth abundance was high. We also found that bats decreased call frequency and bandwidth and increased call duration at higher altitudes and behaved similarly with increasing moth abundance even at ground level. Our results support predictions that bats change foraging behaviour in response to seasonal availability of migratory moths and document alterations in echolocation call parameters that are consistent with optimizing prey detection.
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Affiliation(s)
- J.J. Krauel
- Department of Ecology and Evolutionary Biology, University of Tennessee, 569 Dabney Hall, Knoxville, TN 37996, USA
| | - J.M. Ratcliffe
- Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, ON M5S 3B2, Canada
| | - J.K. Westbrook
- USDA Agricultural Research Service, 2771 F and B Road, College Station, TX 77845, USA
| | - G.F. McCracken
- Department of Ecology and Evolutionary Biology, University of Tennessee, 569 Dabney Hall, Knoxville, TN 37996, USA
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Predator–prey interaction reveals local effects of high-altitude insect migration. Oecologia 2017; 186:49-58. [DOI: 10.1007/s00442-017-3995-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2017] [Accepted: 10/26/2017] [Indexed: 01/05/2023]
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Hayman DTS, Cryan PM, Fricker PD, Dannemiller NG. Long‐term video surveillance and automated analyses reveal arousal patterns in groups of hibernating bats. Methods Ecol Evol 2017. [DOI: 10.1111/2041-210x.12823] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- David T. S. Hayman
- Molecular Epidemiology and Public Health Laboratory Hopkirk Research Institute Massey University Palmerston North New Zealand
| | - Paul M. Cryan
- U.S. Geological Survey Fort Collins Science Center Fort Collins CO USA
| | | | - Nicholas G. Dannemiller
- Department of Fish, Wildlife, and Conservation Biology Colorado State University Fort Collins CO USA
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Tobin A, Chambers CL. Mixed effects of gating subterranean habitat on bats: A review. J Wildl Manage 2017. [DOI: 10.1002/jwmg.21287] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Abigail Tobin
- School of Forestry; Northern Arizona University; Flagstaff AZ 86011 USA
| | - Carol L. Chambers
- School of Forestry; Northern Arizona University; Flagstaff AZ 86011 USA
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Braun De Torrez EC, Samoray ST, Silas KA, Wallrichs MA, Gumbert MW, Ober HK, Mccleery RA. Acoustic lure allows for capture of a high-flying, endangered bat. WILDLIFE SOC B 2017. [DOI: 10.1002/wsb.778] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Elizabeth C. Braun De Torrez
- Department of Wildlife Ecology and Conservation; University of Florida; 110 Newins-Ziegler Hall Gainesville FL 32611 USA
| | - Steve T. Samoray
- Copperhead Environmental Consulting, Inc.; 11641 Richmond Road P.O. Box 73, Paint Lick KY 40461 USA
| | - Kirk A. Silas
- Department of Wildlife Ecology and Conservation; University of Florida; 110 Newins-Ziegler Hall Gainesville FL 32611 USA
| | - Megan A. Wallrichs
- Department of Wildlife Ecology and Conservation; University of Florida; 110 Newins-Ziegler Hall Gainesville FL 32611 USA
| | - Mark W. Gumbert
- Copperhead Environmental Consulting, Inc.; 11641 Richmond Road P.O. Box 73, Paint Lick KY 40461 USA
| | - Holly K. Ober
- Department of Wildlife Ecology and Conservation; University of Florida; 155 Research Road Quincy FL 32351 USA
| | - Robert A. Mccleery
- Department of Wildlife Ecology and Conservation; University of Florida; 314 Newins-Ziegler Hall Gainesville FL 32611 USA
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Lin Y, Abaid N, Müller R. Bats adjust their pulse emission rates with swarm size in the field. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2016; 140:4318. [PMID: 28040047 DOI: 10.1121/1.4971331] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Flying in swarms, e.g., when exiting a cave, could pose a problem to bats that use an active biosonar system because the animals could risk jamming each other's biosonar signals. Studies from current literature have found different results with regard to whether bats reduce or increase emission rate in the presence of jamming ultrasound. In the present work, the number of Eastern bent-wing bats (Miniopterus fuliginosus) that were flying inside a cave during emergence was estimated along with the number of signal pulses recorded. Over the range of average bat numbers present in the recording (0 to 14 bats), the average number of detected pulses per bat increased with the average number of bats. The result was interpreted as an indication that the Eastern bent-wing bats increased their emission rate and/or pulse amplitude with swarm size on average. This finding could be explained by the hypothesis that the bats might not suffer from substantial jamming probabilities under the observed density regimes, so jamming might not have been a limiting factor for their emissions. When jamming did occur, the bats could avoid it through changing the pulse amplitude and other pulse properties such as duration or frequency, which has been suggested by other studies. More importantly, the increased biosonar activities may have addressed a collision-avoidance challenge that was posed by the increased swarm size.
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Affiliation(s)
- Yuan Lin
- Department of Mechanical Engineering, Virginia Tech, 635 Prices Fork Road, Blacksburg, Virginia 24061, USA
| | - Nicole Abaid
- Department of Biomedical Engineering and Mechanics, Virginia Tech, 495 Old Turner Street, Blacksburg, Virginia 24061, USA
| | - Rolf Müller
- Department of Mechanical Engineering, Virginia Tech, 1075 Life Science Circle, Blacksburg, Virginia 24061, USA
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Tattersall GJ. Infrared thermography: A non-invasive window into thermal physiology. Comp Biochem Physiol A Mol Integr Physiol 2016; 202:78-98. [PMID: 26945597 DOI: 10.1016/j.cbpa.2016.02.022] [Citation(s) in RCA: 163] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Revised: 02/26/2016] [Accepted: 02/29/2016] [Indexed: 11/30/2022]
Abstract
Infrared thermography is a non-invasive technique that measures mid to long-wave infrared radiation emanating from all objects and converts this to temperature. As an imaging technique, the value of modern infrared thermography is its ability to produce a digitized image or high speed video rendering a thermal map of the scene in false colour. Since temperature is an important environmental parameter influencing animal physiology and metabolic heat production an energetically expensive process, measuring temperature and energy exchange in animals is critical to understanding physiology, especially under field conditions. As a non-contact approach, infrared thermography provides a non-invasive complement to physiological data gathering. One caveat, however, is that only surface temperatures are measured, which guides much research to those thermal events occurring at the skin and insulating regions of the body. As an imaging technique, infrared thermal imaging is also subject to certain uncertainties that require physical modelling, which is typically done via built-in software approaches. Infrared thermal imaging has enabled different insights into the comparative physiology of phenomena ranging from thermogenesis, peripheral blood flow adjustments, evaporative cooling, and to respiratory physiology. In this review, I provide background and guidelines for the use of thermal imaging, primarily aimed at field physiologists and biologists interested in thermal biology. I also discuss some of the better known approaches and discoveries revealed from using thermal imaging with the objective of encouraging more quantitative assessment.
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Affiliation(s)
- Glenn J Tattersall
- Department of Biological Sciences, Brock University, St. Catharines, Ontario, L2S 3A1, Canada.
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Matzner S, Cullinan VI, Duberstein CA. Two-dimensional thermal video analysis of offshore bird and bat flight. ECOL INFORM 2015. [DOI: 10.1016/j.ecoinf.2015.09.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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39
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Gillam EH, Montero BK. Influence of call structure on the jamming avoidance response of echolocating bats. J Mammal 2015. [DOI: 10.1093/jmammal/gyv147] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Bats rely heavily on echolocation for orientation and prey detection, hence acoustic signals that interfere with echo reception are problematic. When flying in the presence of other bats, some species adjust their echolocation to avoid frequency overlap with the calls of nearby conspecifics, known as a jamming avoidance response (JAR). One aspect of JAR that has not been thoroughly examined is how the spectral structure of the jamming signal impacts the jamming response. Our objective was to examine how the structural characteristics of an echolocation broadcast impact JAR in free-flying Brazilian free-tailed bats, Tadarida brasiliensis . We created 4 echolocation playbacks that differed only in call shape and frequency modulation. We examined the response of bats when flying in the presence of an unchanging broadcast (static stimulus) and when the playback signal was abruptly switched as the bat approached the speaker (dynamic stimulus). Results revealed that the bandwidth of the interfering signal impacted the strength of the observed JAR, while the presence and/or length of a terminal quasi-constant frequency section in the interfering signal did not. Our results agree with laboratory studies documenting JAR in the presence of white noise, as well as field studies demonstrating extensive variability in the echolocation calls of Brazilian free-tailed bats. We relate these results to previous findings on JAR, including a recent study documenting no JAR in a bat species and suggest further experiments to tease apart the physiological limitations of JAR. Overall, this study provides additional insight into the signal processing capabilities of bats and improves our understanding of how bats are able to orient using sound in a noisy world.
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Affiliation(s)
- Erin H. Gillam
- Department of Biological Sciences, NDSU Dept 2715, North Dakota State University , 218 Stevens Hall, P.O.Box 6050, Fargo, ND 58108-6050 , USA (EHG, BKM)
| | - B. Karina Montero
- Department of Biological Sciences, NDSU Dept 2715, North Dakota State University , 218 Stevens Hall, P.O.Box 6050, Fargo, ND 58108-6050 , USA (EHG, BKM)
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Lin Y, Abaid N. Modeling perspectives on echolocation strategies inspired by bats flying in groups. J Theor Biol 2015; 387:46-53. [PMID: 26386143 DOI: 10.1016/j.jtbi.2015.09.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Revised: 08/18/2015] [Accepted: 09/09/2015] [Indexed: 11/28/2022]
Abstract
Bats navigating with echolocation - which is a type of active sensing achieved by interpreting echoes resulting from self-generated ultrasonic pulses - exhibit unique behaviors during group flight. While bats may benefit from eavesdropping on their peers׳ echolocation, they also potentially suffer from confusion between their own and peers׳ pulses, caused by an effect called frequency jamming. This hardship of group flight is supported by experimental observations of bats simplifying their sound-scape by shifting their pulse frequencies or suppressing echolocation altogether. Here, we investigate eavesdropping and varying pulse emission rate from a modeling perspective to understand these behaviors׳ potential benefits and detriments. We define an agent-based model of echolocating bats avoiding collisions in a three-dimensional tunnel. Through simulation, we show that bats with reasonably accurate eavesdropping can reduce collisions compared to those neglecting information from peers. In large populations, bats minimize frequency jamming by decreasing pulse emission rate, while collision risk increases; conversely, increasing pulse emission rate minimizes collisions by allowing more sensing information generated per bat. These strategies offer benefits for both biological and engineered systems, since frequency jamming is a concern in systems using active sensing.
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Affiliation(s)
- Yuan Lin
- Department of Biomedical Engineering and Mechanics, Virginia Polytechnic Institute and State University, Blacksburg, VA, 24061, United States.
| | - Nicole Abaid
- Department of Biomedical Engineering and Mechanics, Virginia Polytechnic Institute and State University, Blacksburg, VA, 24061, United States.
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41
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Weaver SP, Simpson TR, Baccus JT, Weckerly FW. Baseline population estimates and microclimate data for newly established overwintering Brazilian free-tailed bat colonies in central Texas. SOUTHWEST NAT 2015. [DOI: 10.1894/swnat-d-14-00022.1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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42
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McFarlane DA, Rentergem GV, Ruina A, Lundberg J, Christenson K. Estimating Colony Size of the Wrinkle-Lipped Bat,Chaerephon plicatus(Chiroptera: Molossidae) at Gomantong, Sabah, by Quantitative Image Analysis. ACTA CHIROPTEROLOGICA 2015. [DOI: 10.3161/15081109acc2015.17.1.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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43
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Ganow KB, Caire W, Matlack RS. Use of thermal imaging to estimate the population sizes of Brazilian free-tailed bat, Tadarida brasiliensis, maternity roosts in Oklahoma. SOUTHWEST NAT 2015. [DOI: 10.1894/swnat-d-14-00010r1.1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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44
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Krauel JJ, Westbrook JK, McCracken GF. Weather-driven dynamics in a dual-migrant system: moths and bats. J Anim Ecol 2015; 84:604-614. [DOI: 10.1111/1365-2656.12327] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2014] [Accepted: 11/29/2014] [Indexed: 11/28/2022]
Affiliation(s)
| | - John K. Westbrook
- U.S. Department of Agriculture; Agricultural Research Service; 2771 F&B Road College Station TX 77845 USA
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Abstract
Communication signals are susceptible to interference ("jamming") from conspecifics and other sources. Many active sensing animals, including bats and electric fish, alter the frequency of their emissions to avoid inadvertent jamming from conspecifics. We demonstrated that echolocating bats adaptively jam conspecifics during competitions for food. Three-dimensional flight path reconstructions and audio-video field recordings of foraging bats (Tadarida brasiliensis) revealed extended interactions in which bats emitted sinusoidal frequency-modulated ultrasonic signals that interfered with the echolocation of conspecifics attacking insect prey. Playbacks of the jamming call, but not of control sounds, caused bats to miss insect targets. This study demonstrates intraspecific food competition through active disruption of a competitor's sensing during food acquisition.
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Affiliation(s)
- Aaron J Corcoran
- Department of Biology, Wake Forest University, 030 Winston Hall, Winston Salem, NC 27106, USA. Department of Biology, University of Maryland, Biology-Psychology Building, College Park, MD 20742, USA.
| | - William E Conner
- Department of Biology, Wake Forest University, 030 Winston Hall, Winston Salem, NC 27106, USA
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Dell AI, Bender JA, Branson K, Couzin ID, de Polavieja GG, Noldus LPJJ, Pérez-Escudero A, Perona P, Straw AD, Wikelski M, Brose U. Automated image-based tracking and its application in ecology. Trends Ecol Evol 2014; 29:417-28. [PMID: 24908439 DOI: 10.1016/j.tree.2014.05.004] [Citation(s) in RCA: 245] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2013] [Revised: 05/03/2014] [Accepted: 05/06/2014] [Indexed: 11/26/2022]
Abstract
The behavior of individuals determines the strength and outcome of ecological interactions, which drive population, community, and ecosystem organization. Bio-logging, such as telemetry and animal-borne imaging, provides essential individual viewpoints, tracks, and life histories, but requires capture of individuals and is often impractical to scale. Recent developments in automated image-based tracking offers opportunities to remotely quantify and understand individual behavior at scales and resolutions not previously possible, providing an essential supplement to other tracking methodologies in ecology. Automated image-based tracking should continue to advance the field of ecology by enabling better understanding of the linkages between individual and higher-level ecological processes, via high-throughput quantitative analysis of complex ecological patterns and processes across scales, including analysis of environmental drivers.
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Affiliation(s)
- Anthony I Dell
- Systemic Conservation Biology, Department of Biology, Georg-August University Göttingen, Göttingen, Germany.
| | | | - Kristin Branson
- Howard Hughes Medical Institute, Janelia Farm Research Campus, Ashburn, VA, USA
| | - Iain D Couzin
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, USA
| | | | - Lucas P J J Noldus
- Noldus Information Technology BV, Nieuwe Kanaal 5, 6709 PA Wageningen, The Netherlands
| | | | - Pietro Perona
- Computation and Neural Systems Program, California Institute of Technology, Pasadena, CA, USA
| | - Andrew D Straw
- Research Institute of Molecular Pathology (IMP), Vienna, Austria
| | - Martin Wikelski
- Max Planck Institute for Ornithology, Radolfzell, Germany; Biology Department, University of Konstanz, Konstanz, Germany
| | - Ulrich Brose
- Systemic Conservation Biology, Department of Biology, Georg-August University Göttingen, Göttingen, Germany
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López-Hoffman L, Wiederholt R, Sansone C, Bagstad KJ, Cryan P, Diffendorfer JE, Goldstein J, LaSharr K, Loomis J, McCracken G, Medellín RA, Russell A, Semmens D. Market forces and technological substitutes cause fluctuations in the value of bat pest-control services for cotton. PLoS One 2014; 9:e87912. [PMID: 24498400 PMCID: PMC3912186 DOI: 10.1371/journal.pone.0087912] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2013] [Accepted: 01/01/2014] [Indexed: 11/18/2022] Open
Abstract
Critics of the market-based, ecosystem services approach to biodiversity conservation worry that volatile market conditions and technological substitutes will diminish the value of ecosystem services and obviate the “economic benefits” arguments for conservation. To explore the effects of market forces and substitutes on service values, we assessed how the value of the pest-control services provided by Mexican free-tailed bats (Tadarida brasiliensis mexicana) to cotton production in the southwestern U.S. has changed over time. We calculated service values each year from 1990 through 2008 by estimating the value of avoided crop damage and the reduced social and private costs of insecticide use in the presence of bats. Over this period, the ecosystem service value declined by 79% ($19.09 million U.S. dollars) due to the introduction and widespread adoption of Bt (Bacillus thuringiensis) cotton transgenically modified to express its own pesticide, falling global cotton prices and the reduction in the number of hectares in the U.S. planted with cotton. Our results demonstrate that fluctuations in market conditions can cause temporal variation in ecosystem service values even when ecosystem function – in this case bat population numbers – is held constant. Evidence is accumulating, however, of the evolution of pest resistance to Bt cotton, suggesting that the value of bat pest-control services may increase again. This gives rise to an economic option value argument for conserving Mexican free-tailed bat populations. We anticipate that these results will spur discussion about the role of ecosystem services in biodiversity conservation in general, and bat conservation in particular.
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Affiliation(s)
- Laura López-Hoffman
- School of Natural Resources & the Environment, The University of Arizona, Tucson, Arizona, United States of America
- Udall Center for Studies in Public Policy, The University of Arizona, Tucson, Arizona, United States of America
- * E-mail:
| | - Ruscena Wiederholt
- School of Natural Resources & the Environment, The University of Arizona, Tucson, Arizona, United States of America
- Udall Center for Studies in Public Policy, The University of Arizona, Tucson, Arizona, United States of America
| | - Chris Sansone
- Bayer CropScience, Research Triangle Park, North Carolina, United States of America
| | - Kenneth J. Bagstad
- United States Geological Survey, Geosciences and Environmental Change Science Center, Denver, Colorado, United States of America
| | - Paul Cryan
- United States Geological Survey, Fort Collins Science Center, Fort Collins, Colorado, United States of America
| | - Jay E. Diffendorfer
- United States Geological Survey, Geosciences and Environmental Change Science Center, Denver, Colorado, United States of America
| | - Joshua Goldstein
- Department of Human Dimensions of Natural Resources, Colorado State University, Fort Collins, Colorado, United States of America
| | - Kelsie LaSharr
- School of Natural Resources & the Environment, The University of Arizona, Tucson, Arizona, United States of America
| | - John Loomis
- Department of Agricultural and Resource Economics, Colorado State University, Fort Collins, Colorado, United States of America
| | - Gary McCracken
- Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, Tennessee, United States of America
| | - Rodrigo A. Medellín
- Instituto de Ecología, Universidad Nacional Autónoma de México, Distrito Federal, México
| | - Amy Russell
- Department of Biology, Grand Valley State University, Allendale, Michigan, United States of America
| | - Darius Semmens
- United States Geological Survey, Geosciences and Environmental Change Science Center, Denver, Colorado, United States of America
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48
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Wiederholt R, López-Hoffman L, Cline J, Medellín RA, Cryan P, Russell A, McCracken G, Diffendorfer J, Semmens D. Moving across the border: modeling migratory bat populations. Ecosphere 2013. [DOI: 10.1890/es13-00023.1] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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49
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Brawata RL, Raupach TH, Neeman T. Techniques for monitoring carnivore behavior using automatic thermal video. WILDLIFE SOC B 2013. [DOI: 10.1002/wsb.315] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Renee L. Brawata
- Fenner School of Environment and Society; Australian National University; Canberra ACT 0200 Australia
| | - Timothy H. Raupach
- Spectral Imaging and Source Mapping Project; National ICT Australia; Canberra ACT 2601 Australia
| | - Teresa Neeman
- Statistical Consultancy Unit; The Australian National University; Canberra ACT 0200 Australia
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Abstract
AbstractSubterranean environments are essential for the survival of many bat species and other cave fauna but these places are subject to increasing human disturbance. To examine the significance of subterranean habitats for the conservation of bats in China we surveyed bat species in 225 underground sites during 2003–2011. Our results show that 77% of bat species in China, including 30 nationally Endangered or Vulnerable species and nine endemic species, roost in caves and other subterranean habitats. The number of species in occupied roosts was 1–15. Almost 90% of the roosts surveyed contained signs of human disturbance, most of which was from recreational activities. One hundred and twenty-one roosts merit special concern because they harbour ≥ 6 species or > 1,000 individuals, or species of special concern (threatened or endemic species). Generally, larger roosts support more species and a greater abundance of bats than smaller roosts but there is no direct correlation between the presence of species of special concern and roost size. Disused tourist caves have significantly more bat species than other types of roosts. Our data demonstrate that roost disturbance by recreational activities has pronounced detrimental effects on the number of bat species and the presence of species of special concern. We discuss the social, economic and political issues that could adversely affect bat conservation in caves in China, and we recommend that protection of subterranean habitats should be a high priority for bat conservation.
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