1
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Keicher L, Shipley JR, Dietzer MT, Wikelski M, Dechmann DKN. Heart rate monitoring reveals differential seasonal energetic trade-offs in male noctule bats. Proc Biol Sci 2024; 291:20240855. [PMID: 38981523 PMCID: PMC11334998 DOI: 10.1098/rspb.2024.0855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Revised: 06/07/2024] [Accepted: 06/07/2024] [Indexed: 07/11/2024] Open
Abstract
Understanding how animals meet their daily energy requirements is critical in our rapidly changing world. Small organisms with high metabolic rates can conserve stored energy when food availability is low or increase energy intake when energetic requirements are high, but how they balance this in the wild remains largely unknown. Using miniaturized heart rate transmitters, we continuously quantified energy expenditure, torpor use and foraging behaviour of free-ranging male bats (Nyctalus noctula) in spring and summer. In spring, bats used torpor extensively, characterized by lowered heart rates and consequently low energy expenditures. In contrast, in summer, bats consistently avoided torpor, even though they could have used this low-energy mode. As a consequence, daytime heart rates in summer were three times as high compared with the heart rates in spring. Daily energy use increased by 42% during summer, despite lower thermogenesis costs at higher ambient temperatures. Likely, as a consequence, bats nearly doubled their foraging duration. Overall, our results indicate that summer torpor avoidance, beneficial for sperm production and self-maintenance, comes with a high energetic cost. The ability to identify and monitor such vulnerable energetic life-history stages is particularly important to predict how species will deal with increasing temperatures and changes in their resource landscapes.
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Affiliation(s)
- Lara Keicher
- Max Planck Institute of Animal Behavior, Am Obstberg 1, Radolfzell78315, Germany
- Department of Biology, University of Konstanz, Universitätsstraße 10, Konstanz78457, Germany
| | - J. Ryan Shipley
- WLS Institute for Snow and Avalanche Research, Flüelastraße 11, DavosCH-7260, Switzerland
| | - Melina T. Dietzer
- Department of Wildlife Ecology and Management, University of Freiburg, Tennenbacher Straße 4, Freiburg79106, Germany
| | - Martin Wikelski
- Max Planck Institute of Animal Behavior, Am Obstberg 1, Radolfzell78315, Germany
- Department of Biology, University of Konstanz, Universitätsstraße 10, Konstanz78457, Germany
| | - Dina K. N. Dechmann
- Max Planck Institute of Animal Behavior, Am Obstberg 1, Radolfzell78315, Germany
- Department of Biology, University of Konstanz, Universitätsstraße 10, Konstanz78457, Germany
- Cluster for the Advanced Study of Collective Behaviour, University of Konstanz, Universitätsstraße 10, Konstanz78457, Germany
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2
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McGuire LP, Leys R, Webber QMR, Clerc J. Heterothermic Migration Strategies in Flying Vertebrates. Integr Comp Biol 2023; 63:1060-1074. [PMID: 37279461 DOI: 10.1093/icb/icad053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 05/25/2023] [Accepted: 05/29/2023] [Indexed: 06/08/2023] Open
Abstract
Migration is a widespread and highly variable trait among animals. Population-level patterns arise from individual-level decisions, including physiological and energetic constraints. Many aspects of migration are influenced by behaviors and strategies employed during periods of stopover, where migrants may encounter variable or unpredictable conditions. Thermoregulation can be a major cost for homeotherms which largely encounter ambient temperatures below the lower critical temperature during migration, especially during the rest phase of the daily cycle. In this review we describe the empirical evidence, theoretical models, and potential implications of bats and birds that use heterothermy to reduce thermoregulatory costs during migration. Torpor-assisted migration is a strategy described for migrating temperate insectivorous bats, whereby torpor can be used during periods of inactivity to drastically reduce thermoregulatory costs and increase net refueling rate, leading to shorter stopover duration, reduced fuel load requirement, and potential consequences for broad-scale movement patterns and survival. Hummingbirds can adopt a similar strategy, but most birds are not capable of torpor. However, there is an increasing recognition of the use of more shallow heterothermic strategies by diverse bird species during migration, with similarly important implications for migration energetics. A growing body of published literature and preliminary data from ongoing research indicate that heterothermic migration strategies in birds may be more common than traditionally appreciated. We further take a broad evolutionary perspective to consider heterothermy as an alternative to migration in some species, or as a conceptual link to consider alternatives to seasonal resource limitations. There is a growing body of evidence related to heterothermic migration strategies in bats and birds, but many important questions related to the broader implications of this strategy remain.
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Affiliation(s)
- Liam P McGuire
- Department of Biology, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Ryan Leys
- Department of Biology, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Quinn M R Webber
- Department of Integrative Biology, University of Guelph,Guelph, ON N1G 2W1, Canada
| | - Jeff Clerc
- National Renewable Energy Laboratory, Golden, CO 80401, USA
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3
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Keicher L, Shipley JR, Schaeffer PJ, Dechmann DKN. Contrasting Torpor Use by Reproductive Male Common Noctule Bats in the Laboratory and in the Field. Integr Comp Biol 2023; 63:1087-1098. [PMID: 37237444 PMCID: PMC10714913 DOI: 10.1093/icb/icad040] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 05/01/2023] [Accepted: 05/23/2023] [Indexed: 05/28/2023] Open
Abstract
Metabolic processes of animals are often studied in controlled laboratory settings. However, these laboratory settings often do not reflect the animals' natural environment. Thus, results of metabolic measurements from laboratory studies must be cautiously applied to free-ranging animals. Recent technological advances in animal tracking allow detailed eco-physiological studies that reveal when, where, and how physiological measurements from the field differ from those from the laboratory. We investigated the torpor behavior of male common noctule bats (Nyctalus noctula) across different life history stages using two approaches: in controlled laboratory experiments and in the field using calibrated heart rate telemetry. We predicted that non-reproductive males would extensively use torpor to conserve energy, whereas reproductive males would reduce torpor use to promote spermatogenesis. We did not expect differences in torpor use between captive and wild animals as we simulated natural temperature conditions in the laboratory. We found that during the non-reproductive phase, both captive and free-ranging bats used torpor extensively. During reproduction, bats in captivity unexpectedly also used torpor throughout the day, while only free-ranging bats showed the expected reduction in torpor use. Thus, depending on life history stage, torpor behavior in the laboratory was markedly different from the wild. By implementing both approaches and at different life history stages, we were able to better explore the limitations of eco-physiological laboratory studies and make recommendations for when they are an appropriate proxy for natural behavior.
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Affiliation(s)
- Lara Keicher
- Max Planck Institute of Animal Behavior, Am Obstberg 1, 78315 Radolfzell, Germany
- Department of Biology, University of Konstanz, Universitätsstraße 10, 78457 Konstanz, Germany
| | - J Ryan Shipley
- Swiss Federal Institute for Forest, Snow, and Landscape Research WSL, Zürcherstraße 111, Birmensdorf 8903 CH, Switzerland
| | - Paul J Schaeffer
- Department of Biology, Miami University, 700 E. High St., Oxford, OH 45056, USA
| | - Dina K N Dechmann
- Max Planck Institute of Animal Behavior, Am Obstberg 1, 78315 Radolfzell, Germany
- Department of Biology, University of Konstanz, Universitätsstraße 10, 78457 Konstanz, Germany
- Centre for the Advanced Study of Collective Behaviour, Universitätsstraße 10, 78457 Konstanz, Germany
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4
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Vasenkov DA, Vasiliev NS, Sidorchuk NV, Rozhnov VV. Autumn Migration of Greater Noctule Bat (Nyctalus Lasiopterus): through Countries and over Mountains to a New Migration Flight Record in Bats. DOKLADY BIOLOGICAL SCIENCES : PROCEEDINGS OF THE ACADEMY OF SCIENCES OF THE USSR, BIOLOGICAL SCIENCES SECTIONS 2023; 513:395-399. [PMID: 37950812 PMCID: PMC10811110 DOI: 10.1134/s0012496623700746] [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: 07/06/2023] [Revised: 08/30/2023] [Accepted: 09/02/2023] [Indexed: 11/13/2023]
Abstract
For the first time, using GPS-GSM trackers, long-term seasonal flights of greater noctule bat (Nyctalus lasiopterus) from summer habitats in Russia to wintering areas in Europe are recorded. One of the seasonal migratory flights is a record distance for bats (2515 km). The maximum daily flight was 445 km. One of the animals abruptly changed the direction of migration from southwest to north on the third day of flight after crossing the Kursk magnetic anomaly.
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Affiliation(s)
- D A Vasenkov
- Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences, Moscow, Russia.
| | | | - N V Sidorchuk
- Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences, Moscow, Russia
| | - V V Rozhnov
- Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences, Moscow, Russia.
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5
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Hawkes WL, Davies K, Weston S, Moyes K, Chapman JW, Wotton KR. Bat activity correlated with migratory insect bioflows in the Pyrenees. ROYAL SOCIETY OPEN SCIENCE 2023; 10:230151. [PMID: 37593718 PMCID: PMC10427818 DOI: 10.1098/rsos.230151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Accepted: 07/21/2023] [Indexed: 08/19/2023]
Abstract
High altitude mountain passes in the Pyrenees are known to be important migratory hotspots for autumn migrating insects originating from large swathes of northern Europe. In the Pyrenees, prior research has focused on diurnal migratory insects. In this study, we investigate the nocturnal component of the migratory assemblage and ask if this transient food source is also used by bat species. Three seasons of insect trapping revealed 66 species of four different orders, 90% of which were Noctuid moths, including the destructive pest Helicoverpa armigera, otherwise known as the cotton bollworm. Acoustic bat detectors revealed that high activity of Nyctalus spp. and Tadarida teniotis bats were closely synchronized with the arrival of the migratory moths, suggesting this food source is important for both resident and migratory bats to build or maintain energy reserves. Bats of the Nyctalus spp. are likely migrating through the study site using fly-and-forage strategies or stopping over in the area, while resident T. teniotis may be exploiting the abundant food source to build fat stores for hibernation. This study shows that nocturnal migratory insects are abundant in the Pyrenees during autumn and interact during migration, not only with their co-migrant bats but also with resident bat species.
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Affiliation(s)
- Will L. Hawkes
- Centre for Ecology and Conservation, University of Exeter, Cornwall Campus, Penryn, UK
- Swiss Ornithological Institute, Sempach, Switzerland
| | - Kelsey Davies
- Centre for Ecology and Conservation, University of Exeter, Cornwall Campus, Penryn, UK
| | - Scarlett Weston
- Centre for Ecology and Conservation, University of Exeter, Cornwall Campus, Penryn, UK
| | - Kelly Moyes
- Centre for Ecology and Conservation, University of Exeter, Cornwall Campus, Penryn, UK
| | - Jason W. Chapman
- Centre for Ecology and Conservation, University of Exeter, Cornwall Campus, Penryn, UK
- Environment and Sustainability Institute, University of Exeter, Cornwall Campus, Penryn, UK
- Department of Entomology, Nanjing Agricultural University, Nanjing, People's Republic of China
| | - Karl R. Wotton
- Centre for Ecology and Conservation, University of Exeter, Cornwall Campus, Penryn, UK
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6
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Erhardt S, Koch M, Kiefer A, Veith M, Weigel R, Koelpin A. Mobile-BAT-A Novel Ultra-Low Power Wildlife Tracking System. SENSORS (BASEL, SWITZERLAND) 2023; 23:s23115236. [PMID: 37299963 DOI: 10.3390/s23115236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 05/19/2023] [Accepted: 05/26/2023] [Indexed: 06/12/2023]
Abstract
We introduce a novel ultra-low power system for tracking animal movements over long periods with an unprecedented high-temporal-resolution. The localization principle is based on the detection of cellular base stations using a miniaturized software-defined radio, weighing 2.0 g, including the battery, and having a size equivalent to two stacked 1-euro cent coins. Therefore, the system is small and lightweight enough to be deployed on small, wide-ranging, or migrating animals, such as European bats, for movement analysis with an unprecedented spatiotemporal resolution. The position estimation relies on a post-processing probabilistic RF pattern-matching method based on the acquired base stations and power levels. In several field tests, the system has been successfully verified, and a run-time of close to one year has been demonstrated.
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Affiliation(s)
- Stefan Erhardt
- Institute of High Frequency Technology, Hamburg University of Technology, Denickestraße 22, 21073 Hamburg, Germany
- Institute for Electronics Engineering, Friedrich-Alexander-Universität Erlangen-Nürnberg, Cauerstraße 9, 91058 Erlangen, Germany
| | - Martin Koch
- Department of Biogeography, University of Trier, Universitätsring 15, 54286 Trier, Germany
| | - Andreas Kiefer
- Department of Biogeography, University of Trier, Universitätsring 15, 54286 Trier, Germany
| | - Michael Veith
- Department of Biogeography, University of Trier, Universitätsring 15, 54286 Trier, Germany
| | - Robert Weigel
- Institute for Electronics Engineering, Friedrich-Alexander-Universität Erlangen-Nürnberg, Cauerstraße 9, 91058 Erlangen, Germany
| | - Alexander Koelpin
- Institute of High Frequency Technology, Hamburg University of Technology, Denickestraße 22, 21073 Hamburg, Germany
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7
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Flexible energy-saving strategies in female temperate-zone bats. J Comp Physiol B 2022; 192:805-814. [PMID: 35939092 PMCID: PMC9550788 DOI: 10.1007/s00360-022-01452-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 07/06/2022] [Accepted: 07/19/2022] [Indexed: 12/02/2022]
Abstract
Torpor is characterized by an extreme reduction in metabolism and a common energy-saving strategy of heterothermic animals. Torpor is often associated with cold temperatures, but in the last decades, more diverse and flexible forms of torpor have been described. For example, tropical bat species maintain a low metabolism and heart rate at high ambient and body temperatures. We investigated whether bats (Nyctalus noctula) from the cooler temperate European regions also show this form of torpor with metabolic inhibition at high body temperatures, and whether this would be as pronounced in reproductive as in non-reproductive bats. We simultaneously measured metabolic rate, heart rate, and skin temperature in non-reproductive and pregnant females at a range of ambient temperatures. We found that they can decouple metabolic rate and heart rate from body temperature: they maintained an extremely low metabolism and heart rate when exposed to ambient temperatures changing from 0 to 32.5 °C, irrespective of reproductive status. When we simulated natural temperature conditions, all non-reproductive bats used torpor throughout the experiment. Pregnant bats used variable strategies from torpor, to maintaining normothermy, or a combination of both. Even a short torpor bout during the day saved up to 33% of the bats' total energy expenditure. Especially at higher temperatures, heart rate was a much better predictor of metabolic rate than skin temperature. We suggest that the capability to flexibly save energy across a range of ambient temperatures within and between reproductive states may be an important ability of these bats and possibly other temperate-zone heterotherms.
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8
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Rogers EJ, McGuire L, Longstaffe FJ, Clerc J, Kunkel E, Fraser E. Relating wing morphology and immune function to patterns of partial and differential bat migration using stable isotopes. J Anim Ecol 2022; 91:858-869. [PMID: 35218220 DOI: 10.1111/1365-2656.13681] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Accepted: 01/26/2022] [Indexed: 11/28/2022]
Abstract
Migration is energetically expensive and is predicted to drive similar morphological adaptations and physiological trade-offs in migratory bats and birds. Previous studies suggest that fixed traits like wing morphology vary among species and individuals according to selective pressures on flight, while immune defenses can vary flexibly within individuals as energy is variably reallocated throughout the year. We assessed intraspecific variation in wing morphology and immune function in silver-haired bats (Lasionycteris noctivagans), a species that follows both partial and differential migration patterns. We hypothesized that if bats experience energy constraints associated with migration, then wing morphology and immune function should vary based on migratory tendency (sedentary or migratory) and migration distance. We predicted that long-distance migrants would have reduced immune function and more migration-adapted wing shapes compared to resident or short-distance migrating bats. We estimated breeding latitude of spring migrants using stable hydrogen isotope techniques. Our sample consisted primarily of male bats, which we categorized as residents, long-distance northern migrants, short-distance northern migrants, and southern migrants (apparent breeding location south of capture site). Controlling for individual condition and capture date, we related wing characteristics and immune indices among groups. Some, but not all, aspects of wing form and immune function varied between migrants and residents. Long-distance northern migrants had larger wings than short-distance northern migrants and lower wing loading than southern migrants. Compared with resident bats, short-distance northern migrants had reduced IgG while southern migrants had heightened neutrophils and neutrophil-to-lymphocyte ratios. Body fat, aspect ratio, wing tip shape, and bacteria killing ability did not vary with migration status or distance. In general, male silver-haired bats do not appear to mediate migration costs by substantially downregulating immune defenses or to be under stronger selection for wing forms adapted for fast, energy-efficient flight. Such phenotypic changes may be more adaptive for female silver-haired bats, which migrate farther and are more constrained by time in spring than males. Adaptations for aerial hawking and the use of heterothermy by migrating bats may also reduce the energetic cost of migration and the need for more substantial morphological and physiological trade-offs.
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Affiliation(s)
- Elizabeth J Rogers
- Department of Biological Sciences, Texas Tech University, Lubbock, TX, USA.,Organismic and Evolutionary Biology Program, University of Massachusetts, Amherst, MA, USA
| | - Liam McGuire
- Department of Biological Sciences, Texas Tech University, Lubbock, TX, USA.,Department of Biology, University of Waterloo, Waterloo, ON, Canada
| | - Fred J Longstaffe
- Department of Earth Sciences, The University of Western Ontario, London, ON, Canada
| | - Jeff Clerc
- Department of Biological Sciences, Texas Tech University, Lubbock, TX, USA.,Normandeau Associates Inc, Gainesville, FL, USA
| | - Emma Kunkel
- Department of Biological Sciences, Texas Tech University, Lubbock, TX, USA
| | - Erin Fraser
- Environmental Science Program, Memorial University of Newfoundland (Grenfell Campus), Corner Brook, NL, Canada
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9
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Brewer CT, Rauch-Davis WA, Fraser EE. The Use of Intrinsic Markers for Studying the Migratory Movements of Bats. Animals (Basel) 2021; 11:3477. [PMID: 34944252 PMCID: PMC8698158 DOI: 10.3390/ani11123477] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 11/26/2021] [Accepted: 12/01/2021] [Indexed: 11/30/2022] Open
Abstract
Mortality of migratory bat species at wind energy facilities is a well-documented phenomenon, and mitigation and management are partially constrained by the current limited knowledge of bat migratory movements. Analyses of biochemical signatures in bat tissues ("intrinsic markers") can provide information about the migratory origins of individual bats. Many tissue samples for intrinsic marker analysis may be collected from living and dead bats, including carcasses collected at wind energy facilities. In this paper, we review the full suite of available intrinsic marker analysis techniques that may be used to study bat migration, with the goal of summarizing the current literature and highlighting knowledge gaps and opportunities. We discuss applications of the stable isotopes of hydrogen, oxygen, nitrogen, carbon, sulfur; radiogenic strontium isotopes; trace elements and contaminants; and the combination of these markers with each other and with other extrinsic markers. We further discuss the tissue types that may be analyzed for each and provide a synthesis of the generalized workflow required to link bats to origins using intrinsic markers. While stable hydrogen isotope techniques have clearly been the leading approach to infer migratory bat movement patterns across the landscape, here we emphasize a variety of lesser used intrinsic markers (i.e., strontium, trace elements, contaminants) that may address new study areas or answer novel research questions.
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Affiliation(s)
| | | | - Erin E. Fraser
- School of Science and the Environment, Grenfell Campus, Memorial University of Newfoundland, 20 University Drive, Corner Brook, NL A2H 5G4, Canada; (C.T.B.); (W.A.R.-D.)
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10
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Pretorius M, Markotter W, Kearney T, Seamark E, Broders H, Keith M. No Evidence of Pre-Hibernation or Pre-Migratory Body Mass Gain in Miniopterus natalensis in North-Eastern South Africa. JOURNAL OF VERTEBRATE BIOLOGY 2021. [DOI: 10.25225/jvb.20088] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Mariëtte Pretorius
- Mammal Research Institute, Faculty of Natural and Agricultural Sciences, University of Pretoria, Hatfield, South Africa; e-mail: ,
| | - Wanda Markotter
- Department of Medical Virology, Faculty of Health Sciences, Centre for Viral Zoonoses, University of Pretoria, South Africa; e-mail:
| | | | | | - Hugh Broders
- Department of Biology, University of Waterloo, Waterloo, Ontario, Canada; e-mail:
| | - Mark Keith
- Mammal Research Institute, Faculty of Natural and Agricultural Sciences, University of Pretoria, Hatfield, South Africa; e-mail: ,
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11
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Baloun DE, Hobson KA, Guglielmo CG. Temporal patterns of foraging by silver-haired bats during migratory stopover revealed by isotopic analyses (δ 13C) of breath CO 2. Oecologia 2020; 193:67-75. [PMID: 32306117 DOI: 10.1007/s00442-020-04650-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Accepted: 04/08/2020] [Indexed: 11/26/2022]
Abstract
The extent to which migratory bats forage at stopover sites or while in migratory flight is poorly understood. Endogenous fat stores have lower δ13C values relative to the dietary substrates from which they were synthesized, and so, the fed versus fasted state of bats should be discernable by comparing their breath δ13C at capture to that after a known period of fasting. We captured silver-haired bats (Lasionycteris noctivagans) at a stopover site at Long Point, Ontario, Canada, during spring and fall migration. We collected breath samples at capture and after fasting in captivity for 12 h, providing a fasted-state δ13C value corresponding to metabolism of fat stores. We also collected and weighed fecal pellets produced while in captivity. Breath δ13C values at capture were positively correlated with mass of feces produced. During spring migration, δ13C values of breath CO2 at capture were low and similar to fasting values, but increased with date consistent with increased foraging at stopover and reliance on exogenous dietary nutrients as the season progressed. The opposite temporal pattern was found during fall migration. Our findings suggest that bats forage during migratory stopover when environmental conditions permit despite potential time trade-offs between feeding and travel, and the energy savings resulting from torpor during roosting. This study provides insight into the eco-physiology of bat migration and shows the importance of foraging habitat for migratory bats.
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Affiliation(s)
- Dylan E Baloun
- Department of Biology and Advanced Facility for Avian Research (AFAR), University of Western Ontario, London, ON, Canada.
- Department of Biology, University of Saskatchewan, Saskatoon, SK, Canada.
| | - Keith A Hobson
- Department of Biology and Advanced Facility for Avian Research (AFAR), University of Western Ontario, London, ON, Canada
| | - Christopher G Guglielmo
- Department of Biology and Advanced Facility for Avian Research (AFAR), University of Western Ontario, London, ON, Canada
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12
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Voigt CC, Kravchenko K, Liechti F, Bumrungsri S. Skyrocketing Flights as a Previously Unrecognized Behaviour of Open-Space Foraging Bats. ACTA CHIROPTEROLOGICA 2020. [DOI: 10.3161/15081109acc2019.21.2.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Christian C. Voigt
- Department Evolutionary Ecology Leibniz Institute for Zoo and Wildlife Research Alfred-Kowalke-Strasse 17, 10315 Berlin, Germany
| | - Kseniia Kravchenko
- Department Evolutionary Ecology Leibniz Institute for Zoo and Wildlife Research Alfred-Kowalke-Strasse 17, 10315 Berlin, Germany
| | - Felix Liechti
- Swiss Ornithological Institute, Seerose 1, CH-6204 Sempach, Switzerland
| | - Sara Bumrungsri
- Department of Biology, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla, Thailand
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13
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Affiliation(s)
| | - Ulla-Maija Liukko
- Finnish Environment Institute (SYKE), Latokartanonkaari 11, FI-00790 Helsinki, Finland
| | - Torsten Stjernberg
- Finnish Museum of Natural History Luomus, P.O. Box 17, FI-00014 University of Helsinki, Finland
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14
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Jonasson KA, Guglielmo CG. Evidence for spring stopover refuelling in migrating silver-haired bats (Lasionycteris noctivagans). CAN J ZOOL 2019. [DOI: 10.1139/cjz-2019-0036] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Migrating animals must acquire sufficient fuel to sustain migratory movement, but how time is allocated to achieve this can vary greatly. The fuel strategies used by migrating bats are not well understood and have not been investigated during the spring when insectivorous bats face low food abundance. Migrating silver-haired bats (Lasionycteris noctivagans (Le Conte, 1831)) were captured at a stopover site in Long Point, Ontario, Canada, in April and May of 2012–2014. We followed the movements of 40 bats outfitted with radio transmitters using an automated telemetry array and examined the effects of ambient temperature, fat stores, and sex on stopover duration. As seen previously in autumn, most bats departed the evening following capture, but one-third of bats used multiday stopovers. Extended stopover was associated with lower ambient temperature. There was no effect of sex or fat at capture on stopover departure probability. Bats captured closer to dawn had greater fat mass and lean mass than those captured early in the night, a trend indicative of fuel deposition at this site. This is the first study to provide evidence that bats use stopover habitat for refuelling.
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Affiliation(s)
- Kristin A. Jonasson
- Department of Biology, Advanced Facility for Avian Research, University of Western Ontario, 1393 Western Road, London, ON N6G 1G9, Canada
- Department of Biology, Advanced Facility for Avian Research, University of Western Ontario, 1393 Western Road, London, ON N6G 1G9, Canada
| | - Christopher G. Guglielmo
- Department of Biology, Advanced Facility for Avian Research, University of Western Ontario, 1393 Western Road, London, ON N6G 1G9, Canada
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15
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Teague O'Mara M, Wikelski M, Kranstauber B, Dechmann DKN. First three-dimensional tracks of bat migration reveal large amounts of individual behavioral flexibility. Ecology 2019; 100:e02762. [PMID: 31127630 DOI: 10.1002/ecy.2762] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Revised: 04/08/2019] [Accepted: 04/25/2019] [Indexed: 11/09/2022]
Affiliation(s)
- M Teague O'Mara
- Department of Migration, Max Planck Institute of Animal Behavior, Am Obstberg 1, Radolfzell, 78315, Germany.,Department of Biology, University of Konstanz, Universitätstr. 10, Konstanz, 78457, Germany.,Centre for the Advanced Study of Collective Behaviour, University of Konstanz, Universitätstr. 10, Konstanz, 78457, Germany
| | - Martin Wikelski
- Department of Migration, Max Planck Institute of Animal Behavior, Am Obstberg 1, Radolfzell, 78315, Germany.,Department of Biology, University of Konstanz, Universitätstr. 10, Konstanz, 78457, Germany
| | - Bart Kranstauber
- Department of Migration, Max Planck Institute of Animal Behavior, Am Obstberg 1, Radolfzell, 78315, Germany.,Department of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurstr. 190, Zurich, 8057, Switzerland
| | - Dina K N Dechmann
- Department of Migration, Max Planck Institute of Animal Behavior, Am Obstberg 1, Radolfzell, 78315, Germany.,Department of Biology, University of Konstanz, Universitätstr. 10, Konstanz, 78457, Germany
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16
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O'Mara MT, Wikelski M, Kranstauber B, Dechmann DKN. Common noctules exploit low levels of the aerosphere. ROYAL SOCIETY OPEN SCIENCE 2019; 6:181942. [PMID: 30891300 PMCID: PMC6408413 DOI: 10.1098/rsos.181942] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Accepted: 02/06/2019] [Indexed: 06/09/2023]
Abstract
Aerial habitats present a challenge to find food across a large potential search volume, particularly for insectivorous bats that rely on echolocation calls with limited detection range and may forage at heights over 1000 m. To understand how bats use vertical space, we tracked one to five foraging flights of eight common noctules (Nyctalus noctula). Bats were tracked for their full foraging session (87.27 ± 24 min) using high-resolution atmospheric pressure radio transmitters that allowed us to calculate height and wingbeat frequency. Bats used diverse flight strategies, but generally flew lower than 40 m, with scouting flights to 100 m and a maximum of 300 m. We found no influence of weather on height, and high-altitude ascents were not preceded by an increase in foraging effort. Wingbeat frequency was independent from climbing or descending flight, and bats skipped wingbeats or glided in 10% of all observations. Wingbeat frequency was positively related to capture mass, and wingbeat frequency was positively related to time of night, indicating an effect of load increase over a foraging bout. Overall, individuals used a wide range of airspace including altitudes that put them at increased risk from human-made structures. Further work is needed to test the context of these flight decisions, particularly as individuals migrate throughout Europe.
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Affiliation(s)
- M. Teague O'Mara
- Department of Migration and Immuno-Ecology, Max Planck Institute for Ornithology, Am Obstberg 1, 78315 Radolfzell, Germany
- Department of Biology, University of Konstanz, Universitätstrasse 10, 78464 Konstanz, Germany
| | - Martin Wikelski
- Department of Migration and Immuno-Ecology, Max Planck Institute for Ornithology, Am Obstberg 1, 78315 Radolfzell, Germany
- Department of Biology, University of Konstanz, Universitätstrasse 10, 78464 Konstanz, Germany
| | - Bart Kranstauber
- Department of Migration and Immuno-Ecology, Max Planck Institute for Ornithology, Am Obstberg 1, 78315 Radolfzell, Germany
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, Zurich 8057, Switzerland
| | - Dina K. N. Dechmann
- Department of Migration and Immuno-Ecology, Max Planck Institute for Ornithology, Am Obstberg 1, 78315 Radolfzell, Germany
- Department of Biology, University of Konstanz, Universitätstrasse 10, 78464 Konstanz, Germany
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17
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Baloun DE, Guglielmo CG. Energetics of migratory bats during stopover: a test of the torpor-assisted migration hypothesis. J Exp Biol 2019; 222:jeb.196691. [DOI: 10.1242/jeb.196691] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Accepted: 02/13/2019] [Indexed: 02/04/2023]
Abstract
The torpor-assisted migration hypothesis posits that migration is facilitated in bats by the use of torpor during stopover roosting periods, and predicts that at stopover bats regulate time in torpor facultatively so that daily energy expenditure is independent of ambient roosting temperature. Energy savings can thus be directed to migratory movement. However, direct measurements of total roosting energy expenditure in relation to ambient and body temperature are lacking. We captured migratory silver-haired bats (Lasionycteris noctivagans; ∼11g) at Long Point, Ontario, Canada in spring and fall 2016. We used quantitative magnetic resonance analysis to measure body composition change and energy expenditure over a twelve-hour roosting period in a ventilated incubator at 10, 17 and 25°C. We assessed the effects of season, body mass, sex and age on energy expenditure. We found that daily energy expenditure was independent of roosting temperature, and that this was achieved by flexible use of torpor. Variation in body mass at capture was driven mainly by differences in fat, and the amount of body fat was negatively related to torpor use, particularly in spring. Season, sex and age also affected torpor use and energy expenditure, notably with pregnant females being generally fatter and using less torpor than males in spring. We estimate that stopover contributes only 15-20% to the total energy costs of migration in bats compared to 70% or more in typical birds. This study provides support for the torpor-assisted migration hypothesis, and furthers our understanding of the energy budgets of migratory bats.
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Affiliation(s)
- Dylan E. Baloun
- Department of Biology, Advanced Facility for Avian Research, University of Western Ontario, London, Ontario, Canada
| | - Christopher G. Guglielmo
- Department of Biology, Advanced Facility for Avian Research, University of Western Ontario, London, Ontario, Canada
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18
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Wu H, Jiang T, Huang X, Feng J. Patterns of sexual size dimorphism in horseshoe bats: Testing Rensch's rule and potential causes. Sci Rep 2018; 8:2616. [PMID: 29422495 PMCID: PMC5805768 DOI: 10.1038/s41598-018-21077-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 01/29/2018] [Indexed: 11/10/2022] Open
Abstract
Rensch's rule, stating that sexual size dimorphism (SSD) becomes more evident and male-biased with increasing body size, has been well supported for taxa that exhibit male-biased SSD. Bats, primarily having female-biased SSD, have so far been tested for whether SSD allometry conforms to Rensch's rule in only three studies. However, these studies did not consider phylogeny, and thus the mechanisms underlying SSD variations in bats remain unclear. Thus, the present study reviewed published and original data, including body size, baculum size, and habitat types in 45 bats of the family Rhinolophidae to determine whether horseshoe bats follow Rensch's rule using a phylogenetic comparative framework. We also investigated the potential effect of postcopulatory sexual selection and habitat type on SSD. Our findings indicated that Rensch's rule did not apply to Rhinolophidae, suggesting that SSD did not significantly vary with increasing size. This pattern may be attributable interactions between weak sexual selection to male body size and strong fecundity selection for on female body size. The degree of SSD among horseshoe bats may be attributed to a phylogenetic effect rather than to the intersexual competition for food or to baculum length. Interestingly, we observed that species in open habitats exhibited greater SSD than those in dense forests, suggesting that habitat types may be associated with variations in SSD in horseshoe bats.
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Affiliation(s)
- Hui Wu
- College of Animal Science and Technology, Jilin Agricultural University, Xincheng ST 2888, Changchun, 130118, China
- Jilin Provincal Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, Jingyue St 2555, Changchun, 130117, China
| | - Tinglei Jiang
- Jilin Provincal Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, Jingyue St 2555, Changchun, 130117, China.
- Key Laboratory of Vegetation Ecology of Education Ministry, Institute of Grassland Science, Northeast Normal University, Changchun, 130024, China.
| | - Xiaobin Huang
- Jilin Provincal Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, Jingyue St 2555, Changchun, 130117, China
| | - Jiang Feng
- College of Animal Science and Technology, Jilin Agricultural University, Xincheng ST 2888, Changchun, 130118, China.
- Jilin Provincal Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, Jingyue St 2555, Changchun, 130117, China.
- Key Laboratory of Vegetation Ecology of Education Ministry, Institute of Grassland Science, Northeast Normal University, Changchun, 130024, China.
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19
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Dechmann DKN, Wikelski M, Ellis-Soto D, Safi K, O'Mara MT. Determinants of spring migration departure decision in a bat. Biol Lett 2017; 13:rsbl.2017.0395. [PMID: 28931730 PMCID: PMC5627173 DOI: 10.1098/rsbl.2017.0395] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Accepted: 08/29/2017] [Indexed: 12/03/2022] Open
Abstract
Migratory decisions in birds are closely tied to environmental cues and fat stores, but it remains unknown if the same variables trigger bat migration. To learn more about the rare phenomenon of bat migration, we studied departure decisions of female common noctules (Nyctalus noctula) in southern Germany. We did not find the fattening period that modulates departure decisions in birds. Female noctules departed after a regular evening foraging session, uniformly heading northeast. As the day of year increased, migratory decisions were based on the interactions among wind speed, wind direction and air pressure. As the migration season progressed, bats were likely to migrate on nights with higher air pressure and faster tail winds in the direction of travel, and also show high probability of migration on low-pressure nights with slow head winds. Common noctules thus monitor complex environmental conditions to find the optimal migration night.
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Affiliation(s)
- Dina K N Dechmann
- Department of Immuno-ecology and Migration, Max Planck Institute for Ornithology, 78315 Radolfzell, Germany .,Department of Biology, University of Konstanz, 78464 Konstanz, Germany
| | - M Wikelski
- Department of Immuno-ecology and Migration, Max Planck Institute for Ornithology, 78315 Radolfzell, Germany.,Department of Biology, University of Konstanz, 78464 Konstanz, Germany
| | - D Ellis-Soto
- Department of Immuno-ecology and Migration, Max Planck Institute for Ornithology, 78315 Radolfzell, Germany.,Department of Biology, University of Konstanz, 78464 Konstanz, Germany
| | - K Safi
- Department of Immuno-ecology and Migration, Max Planck Institute for Ornithology, 78315 Radolfzell, Germany.,Department of Biology, University of Konstanz, 78464 Konstanz, Germany
| | - M Teague O'Mara
- Department of Immuno-ecology and Migration, Max Planck Institute for Ornithology, 78315 Radolfzell, Germany .,Department of Biology, University of Konstanz, 78464 Konstanz, Germany
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20
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Roeleke M, Bumrungsri S, Voigt CC. Bats probe the aerosphere during landscape-guided altitudinal flights. Mamm Rev 2017. [DOI: 10.1111/mam.12109] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Manuel Roeleke
- Leibniz Institute for Zoo and Wildlife Research; Alfred-Kowalke-Str. 17 10315 Berlin Germany
- Germany and Department of Animal Behaviour; Freie Universität Berlin; Takustr. 6 14195,Berlin Germany
| | - Sara Bumrungsri
- Department of Biology; Prince of Songkla University; Hat Yai Songkla 90112 Thailand
| | - Christian C. Voigt
- Leibniz Institute for Zoo and Wildlife Research; Alfred-Kowalke-Str. 17 10315 Berlin Germany
- Germany and Department of Animal Behaviour; Freie Universität Berlin; Takustr. 6 14195,Berlin Germany
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21
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O’Mara MT, Bauer K, Blank D, Baldwin JW, Dechmann DKN. Common Noctule Bats Are Sexually Dimorphic in Migratory Behaviour and Body Size but Not Wing Shape. PLoS One 2016; 11:e0167027. [PMID: 27880791 PMCID: PMC5120837 DOI: 10.1371/journal.pone.0167027] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Accepted: 11/08/2016] [Indexed: 11/28/2022] Open
Abstract
Within the large order of bats, sexual size dimorphism measured by forearm length and body mass is often female-biased. Several studies have explained this through the effects on load carrying during pregnancy, intrasexual competition, as well as the fecundity and thermoregulation advantages of increased female body size. We hypothesized that wing shape should differ along with size and be under variable selection pressure in a species where there are large differences in flight behaviour. We tested whether load carrying, sex differential migration, or reproductive advantages of large females affect size and wing shape dimorphism in the common noctule (Nyctalus noctula), in which females are typically larger than males and only females migrate long distances each year. We tested for univariate and multivariate size and shape dimorphism using data sets derived from wing photos and biometric data collected during pre-migratory spring captures in Switzerland. Females had forearms that are on average 1% longer than males and are 1% heavier than males after emerging from hibernation, but we found no sex differences in other size, shape, or other functional characters in any wing parameters during this pre-migratory period. Female-biased size dimorphism without wing shape differences indicates that reproductive advantages of big mothers are most likely responsible for sexual dimorphism in this species, not load compensation or shape differences favouring aerodynamic efficiency during pregnancy or migration. Despite large behavioural and ecological sex differences, morphology associated with a specialized feeding niche may limit potential dimorphism in narrow-winged bats such as common noctules and the dramatic differences in migratory behaviour may then be accomplished through plasticity in wing kinematics.
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Affiliation(s)
- M. Teague O’Mara
- Department of Migration and Immuno-ecology, Max Planck Institute for Ornithology, Radolfzell, Germany
- Department of Biology, University of Konstanz, Konstanz, Germany
- Smithsonian Tropical Research Institute, Balboa, Ancón, Panamá
- * E-mail:
| | - Karla Bauer
- Department of Migration and Immuno-ecology, Max Planck Institute for Ornithology, Radolfzell, Germany
- Department of Biology, University of Konstanz, Konstanz, Germany
| | - Dominik Blank
- Department of Migration and Immuno-ecology, Max Planck Institute for Ornithology, Radolfzell, Germany
- Department of Biology, University of Konstanz, Konstanz, Germany
| | - Justin W. Baldwin
- Department of Migration and Immuno-ecology, Max Planck Institute for Ornithology, Radolfzell, Germany
| | - Dina K. N. Dechmann
- Department of Migration and Immuno-ecology, Max Planck Institute for Ornithology, Radolfzell, Germany
- Department of Biology, University of Konstanz, Konstanz, Germany
- Smithsonian Tropical Research Institute, Balboa, Ancón, Panamá
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22
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Weller TJ, Castle KT, Liechti F, Hein CD, Schirmacher MR, Cryan PM. First Direct Evidence of Long-distance Seasonal Movements and Hibernation in a Migratory Bat. Sci Rep 2016; 6:34585. [PMID: 27698492 PMCID: PMC5048302 DOI: 10.1038/srep34585] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Accepted: 09/14/2016] [Indexed: 12/01/2022] Open
Abstract
Understanding of migration in small bats has been constrained by limitations of techniques that were labor-intensive, provided coarse levels of resolution, or were limited to population-level inferences. Knowledge of movements and behaviors of individual bats have been unknowable because of limitations in size of tracking devices and methods to attach them for long periods. We used sutures to attach miniature global positioning system (GPS) tags and data loggers that recorded light levels, activity, and temperature to male hoary bats (Lasiurus cinereus). Results from recovered GPS tags illustrated profound differences among movement patterns by individuals, including one that completed a >1000 km round-trip journey during October 2014. Data loggers allowed us to record sub-hourly patterns of activity and torpor use, in one case over a period of 224 days that spanned an entire winter. In this latter bat, we documented 5 torpor bouts that lasted ≥16 days and a flightless period that lasted 40 nights. These first uses of miniature tags on small bats allowed us to discover that male hoary bats can make multi-directional movements during the migratory season and sometimes hibernate for an entire winter.
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Affiliation(s)
- Theodore J. Weller
- USDA Forest Service, Pacific Southwest Research Station, 1700 Bayview Drive, Arcata, California, 95521, USA
| | - Kevin T. Castle
- Wildlife Veterinary Consulting, 840 Sundance Drive, Livermore, Colorado, 80536, USA
| | - Felix Liechti
- Swiss Ornithological Institute, Seerose 1, 6204 Sempach, Switzerland
| | - Cris D. Hein
- Bat Conservation International, PO Box 162603, Austin, Texas, 78716, USA
| | | | - Paul M. Cryan
- U.S. Geological Survey Fort Collins Science Center, 2150 Centre Avenue, Building C, Fort Collins, Colorado, 80526, USA
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23
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Castle KT, Weller TJ, Cryan PM, Hein CD, Schirmacher MR. Using sutures to attach miniature tracking tags to small bats for multimonth movement and behavioral studies. Ecol Evol 2015; 5:2980-9. [PMID: 26306181 PMCID: PMC4542000 DOI: 10.1002/ece3.1584] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2015] [Revised: 06/07/2015] [Accepted: 06/08/2015] [Indexed: 11/11/2022] Open
Abstract
Determining the detailed movements of individual animals often requires them to carry tracking devices, but tracking broad-scale movement of small bats (<30 g) has been limited by transmitter technology and long-term attachment methods. This limitation inhibits our understanding of bat dispersal and migration, particularly in the context of emerging conservation issues such as fatalities at wind turbines and diseases. We tested a novel method of attaching lightweight global positioning system (GPS) tags and geolocating data loggers to small bats. We used monofilament, synthetic, absorbable sutures to secure GPS tags and data loggers to the skin of anesthetized big brown bats (Eptesicus fuscus) in Colorado and hoary bats (Lasiurus cinereus) in California. GPS tags and data loggers were sutured to 17 bats in this study. Three tagged bats were recaptured 7 months after initial deployment, with tags still attached; none of these bats showed ill effects from the tag. No severe injuries were apparent upon recapture of 6 additional bats that carried tags up to 26 days after attachment; however, one of the bats exhibited skin chafing. Use of absorbable sutures to affix small tracking devices seems to be a safe, effective method for studying movements of bats over multiple months, although additional testing is warranted. This new attachment method has the potential to quickly advance our understanding of small bats, particularly as more sophisticated miniature tracking devices (e.g., satellite tags) become available.
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Affiliation(s)
| | - Theodore J Weller
- Pacific Southwest Research Station, United States Department of Agriculture Forest Service Arcata, California
| | - Paul M Cryan
- Fort Collins Science Center, United States Geological Survey Fort Collins, Colorado
| | - Cris D Hein
- Bat Conservation International Austin, Texas
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