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Cabrera-Cruz SA, Aguilar López JL, Aguilar-Rodríguez PA, Oropeza-Sánchez MT, Muñoz Jiménez O, Villegas Patraca R. Changes in diversity and species composition in the assemblage of live and dead bats at wind farms in a highly diverse region. ENVIRONMENTAL MONITORING AND ASSESSMENT 2023; 195:1480. [PMID: 37968519 DOI: 10.1007/s10661-023-12090-z] [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: 05/22/2023] [Accepted: 11/02/2023] [Indexed: 11/17/2023]
Abstract
Besides direct mortality, wind farms also affect aerial fauna by modifying their communities, reducing species diversity and richness through disturbance. During three consecutive years, we used mist nets and acoustic recorders, and conducted carcass searches, to characterize the assemblage of bat species and to estimate bat mortality at two nearby wind farms sited <5 km apart in a highly biodiverse region. We asked whether the diversity, richness and evenness of the assemblages varied yearly, predicting it would decrease through time. Richness and evenness did not change, but the diversity of species recorded acoustically, 96% being aerial insectivores, was significantly lower the third year. We estimate 4 - 15.7 fatalities/MW/year by wind farm, with 63% of species found as carcasses being aerial insectivores. We found >40% of dissimilarity in the species composition of bat assemblages between wind farms despite the short distance between them, with species turnover accounting for more than half of the dissimilarity every year. Similarly, species turnover accounted for >15% of the dissimilarity in the composition of the assemblage of live bats (captured and recorded acoustically) and the assemblage obtained through carcass searches. Our findings suggest that nearby wind farms impact bat communities differentially and aerial insectivores disproportionally. Long term, multi-method surveys are needed to characterize bat communities in highly diverse regions and to evaluate the post-construction effects that wind farms have on them.
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Affiliation(s)
- Sergio A Cabrera-Cruz
- Unidad de Servicios Profesionales Altamente Especializados (USPAE), Instituto de Ecología A.C. (INECOL), Coatepec, Veracruz, 91520, México.
| | - José Luis Aguilar López
- Unidad de Servicios Profesionales Altamente Especializados (USPAE), Instituto de Ecología A.C. (INECOL), Coatepec, Veracruz, 91520, México
| | | | - Marco T Oropeza-Sánchez
- Instituto de Investigaciones en Ecosistemas y Sustentabilidad (IESS), Universidad Nacional Autónoma de México, Morelia, Michoacán, 58190, México
| | - Oscar Muñoz Jiménez
- Unidad de Servicios Profesionales Altamente Especializados (USPAE), Instituto de Ecología A.C. (INECOL), Coatepec, Veracruz, 91520, México
| | - Rafael Villegas Patraca
- Unidad de Servicios Profesionales Altamente Especializados (USPAE), Instituto de Ecología A.C. (INECOL), Coatepec, Veracruz, 91520, México.
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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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3
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Sandoval-Herrera NI, Mastromonaco GF, Becker DJ, Simmons NB, Welch KC. Inter- and intra-specific variation in hair cortisol concentrations of Neotropical bats. CONSERVATION PHYSIOLOGY 2021; 9:coab053. [PMID: 34267922 PMCID: PMC8278960 DOI: 10.1093/conphys/coab053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Revised: 06/13/2021] [Accepted: 07/08/2021] [Indexed: 06/13/2023]
Abstract
Quantifying hair cortisol has become popular in wildlife ecology for its practical advantages for evaluating stress. Before hair cortisol levels can be reliably interpreted, however, it is key to first understand the intrinsic factors explaining intra- and inter-specific variation. Bats are an ecologically diverse group of mammals that allow studying such variation. Given that many bat species are threatened or have declining populations in parts of their range, minimally invasive tools for monitoring colony health and identifying cryptic stressors are needed to efficiently direct conservation efforts. Here we describe intra- and inter-specific sources of variation in hair cortisol levels in 18 Neotropical bat species from Belize and Mexico. We found that fecundity is an important ecological trait explaining inter-specific variation in bat hair cortisol. Other ecological variables such as colony size, roost durability and basal metabolic rate did not explain hair cortisol variation among species. At the individual level, females exhibited higher hair cortisol levels than males and the effect of body mass varied among species. Overall, our findings help validate and accurately apply hair cortisol as a monitoring tool in free-ranging bats.
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Affiliation(s)
- Natalia I Sandoval-Herrera
- Department of Ecology and Evolutionary Biology, University of Toronto, Ontario, M5S 3B2, Canada
- Department of Biological Sciences, University of Toronto Scarborough, Ontario, M1C 1A4, Canada
| | | | - Daniel J Becker
- Department of Biology, University of Oklahoma, Norman, OK 73019, USA
| | - Nancy B Simmons
- Department of Mammalogy, Division of Vertebrate Zoology, American Museum of Natural History, New York, NY, 10024-5102, USA
| | - Kenneth C Welch
- Department of Ecology and Evolutionary Biology, University of Toronto, Ontario, M5S 3B2, Canada
- Department of Biological Sciences, University of Toronto Scarborough, Ontario, M1C 1A4, Canada
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Owen RD, Camp JV. Bats of Paraguay: Specimen Data Reveal Ecoregional Preferences and Diverse Seasonal Patterns. ACTA CHIROPTEROLOGICA 2021. [DOI: 10.3161/15081109acc2021.23.1.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Robert D. Owen
- Centro para el Desarrollo de Investigación Científica, Manduvira 635, Asunción, C.P. 1255, Paraguay
| | - Jeremy V. Camp
- Institute of Virology, University of Veterinary Medicine Vienna, Veterinaerplatz 1, 1210 Vienna, Austria
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Cabrera-Cruz SA, Cervantes-Pasqualli J, Franquesa-Soler M, Muñoz-Jiménez Ó, Rodríguez-Aguilar G, Villegas-Patraca R. Estimates of aerial vertebrate mortality at wind farms in a bird migration corridor and bat diversity hotspot. Glob Ecol Conserv 2020. [DOI: 10.1016/j.gecco.2020.e00966] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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Hsiung AC, Boyle WA, Cooper RJ, Chandler RB. Altitudinal migration: ecological drivers, knowledge gaps, and conservation implications. Biol Rev Camb Philos Soc 2018; 93:2049-2070. [DOI: 10.1111/brv.12435] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Revised: 05/14/2018] [Accepted: 05/17/2018] [Indexed: 11/28/2022]
Affiliation(s)
- An C. Hsiung
- Warnell School of Forestry and Natural Resources; University of Georgia; 180 E. Green Street, Athens GA 30602 U.S.A
| | - W. Alice Boyle
- Division of Biology; Kansas State University; 116 Ackert Hall Manhattan KS 66506-4901 U.S.A
| | - Robert J. Cooper
- Warnell School of Forestry and Natural Resources; University of Georgia; 180 E. Green Street, Athens GA 30602 U.S.A
| | - Richard B. Chandler
- Warnell School of Forestry and Natural Resources; University of Georgia; 180 E. Green Street, Athens GA 30602 U.S.A
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Davy CM, Mastromonaco GF, Riley JL, Baxter-Gilbert JH, Mayberry H, Willis CKR. Conservation implications of physiological carry-over effects in bats recovering from white-nose syndrome. CONSERVATION BIOLOGY : THE JOURNAL OF THE SOCIETY FOR CONSERVATION BIOLOGY 2017; 31:615-624. [PMID: 27641049 DOI: 10.1111/cobi.12841] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Revised: 07/19/2016] [Accepted: 08/29/2016] [Indexed: 06/06/2023]
Abstract
Although it is well documented that infectious diseases can pose threats to biodiversity, the potential long-term consequences of pathogen exposure on individual fitness and its effects on population viability have rarely been studied. We tested the hypothesis that pathogen exposure causes physiological carry-over effects with a pathogen that is uniquely suited to this question because the infection period is specific and time limited. The fungus Pseudogymnoascus destructans causes white-nose syndrome (WNS) in hibernating bats, which either die due to the infection while hibernating or recover following emergence from hibernation. The fungus infects all exposed individuals in an overwintering site simultaneously, and bats that survive infection during hibernation clear the pathogen within a few weeks following emergence. We quantified chronic stress during the active season, when bats are not infected, by measuring cortisol in bat claws. Free-ranging Myotis lucifugus who survived previous exposure to P. destructans had significantly higher levels of claw cortisol than naïve individuals. Thus, cryptic physiological carry-over effects of pathogen exposure may persist in asymptomatic, recovered individuals. If these effects result in reduced survival or reproductive success, they could also affect population viability and even act as a third stream in the extinction vortex. For example, significant increases in chronic stress, such as those indicated here, are correlated with reduced reproductive success in a number of species. Future research should directly explore the link between pathogen exposure and the viability of apparently recovered populations to improve understanding of the true impacts of infectious diseases on threatened populations.
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Affiliation(s)
- Christina M Davy
- Natural Resources DNA Profiling and Forensics Centre, Trent University, Peterborough, ON, K9J 7B8, Canada
- Department of Biology, University of Winnipeg, Winnipeg Canada, 515 Portage Avenue, Winnipeg, MB, R3B 2E9, Canada
| | | | - Julia L Riley
- Division of Brain, Behaviour and Evolution, Department of Biological Sciences, Macquarie University, Sydney, New South Wales, 2122, Australia
| | - James H Baxter-Gilbert
- Division of Brain, Behaviour and Evolution, Department of Biological Sciences, Macquarie University, Sydney, New South Wales, 2122, Australia
| | - Heather Mayberry
- Department of Biology, University of Winnipeg, Winnipeg Canada, 515 Portage Avenue, Winnipeg, MB, R3B 2E9, Canada
- Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, ON, M5S 3B2, Canada
| | - Craig K R Willis
- Department of Biology, University of Winnipeg, Winnipeg Canada, 515 Portage Avenue, Winnipeg, MB, R3B 2E9, Canada
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Affiliation(s)
| | - Adam T. Ford
- University of British Columbia; Okanagan Campus, 3333 University Way Kelowna British Columbia Canada V1V 1V7
| | - Kevin C. Fraser
- Department of Biological Sciences; University of Manitoba; Winnipeg MB Canada R3T 2N2
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Ramírez Hernández G, Herrera M. LG. Allocation of endogenous nutrients for reproduction in the lesser long-nosed bat (
Leptonycteris yerbabuenae
) in central Mexico. J Mammal 2016. [DOI: 10.1093/jmammal/gyv149] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
In contrast to birds, the contribution of body reserves to sustain reproductive activities of migratory bats has not being examined. We used C stable isotope analysis to track the importance of nutrients stored in body tissues of the lesser long-nosed bat ( Leptonycteris yerbabuenae ) in Central Mexico. The bat migrates seasonally between areas dominated by vegetation types with contrasting C stable isotope values: in spring–summer, it forages in cactus forests before commuting to dry and wet forests, where mating and births occur. We collected breath and whole blood from nonreproductive individuals in a cactus forest in spring–mid-summer, from mating individuals in an evergreen forest in mid-late summer, and from lactating females in winter in a tropical deciduous forest. We also collected hair and milk from lactating females and several tissues from naturally aborted fetus in late autumn. We tested the hypothesis that nutrient reserves accumulated in cactus forest contribute to the maintenance of adults when they commute to their reproductive grounds, to the construction of offspring tissues during pregnancy, and to the production of milk. The importance of energy stores accumulated in cactus forests to fuel oxidative metabolism was marginal for mating males but it was high for some mating females. Nutrient stores accumulated in cactus forests contributed to ~50% of synthesis of fetus tissues but their contribution for milk production was negligible. Female lesser long-nosed bats can be described as capital-income breeders in relation to the development of offspring during gestation and as incomer breeders in relation to lactation.
En contraste con las aves, la contribución de las reservas corporales para mantener las actividades reproductivas no ha sido evaluada en los murciélagos migratorios. En este estudio, usamos análisis de isótopos estables de C para reconstruir la importancia de los nutrientes almacenados en los tejidos del murciélago magueyero menor ( Leptonycteris yerbabuenae ) en el centro de México. Este murciélago migra estacionalmente entre áreas dominadas por tipos de vegetación con valores contrastantes de isótopos estables de C: la especie forrajea en bosques de cactáceas en primavera-verano antes de moverse a bosques secos y húmedos donde ocurren el apareamiento y los nacimientos. Se colectaron muestras de aliento y sangre entera de individuos no reproductivos en un bosque de cactáceas en primavera y mediados del verano, de individuos en etapa de apareamiento en un bosque húmedo a mediados y finales del verano, y de hembras lactantes en el invierno en un bosque seco tropical. Además, se colectaron muestras de pelo y leche de las hembras lactantes, y de varios tejidos de fetos a finales del otoño. Se probó la hipótesis de que las reservas de nutrientes acumuladas en el bosque de cactáceas contribuyen al mantenimiento de los adultos cuando se mueven a sus sitios de apareamiento, a la construcción de tejidos de las crías durante la preñez, y a la producción de leche. La importancia de las reservas de energía acumuladas en los bosques de cactáceas fue marginal para los machos y fue alta para algunas hembras durante el apareamiento. Los nutrientes acumulados en los bosques de cactáceas contribuyeron en hasta el 50% de la síntesis de tejidos de los fetos pero su contribución para la producción de leche fue de poca importancia. Las hembras de los murciélagos magueyeros menores siguen una estrategia reproductiva mixta de uso de reservas acumuladas y de nutrientes externos en relación al desarrollo de las crías durante la gestación, y una estrategia de uso de nutrientes externos en relación a la lactancia.
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Systematic variation in the stable hydrogen isotope (δ2H) composition of fur from summer populations of two species of temperate insectivorous bats. Mamm Biol 2015. [DOI: 10.1016/j.mambio.2015.03.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Fraser E, Longstaffe F, Fenton M. Moulting matters: the importance of understanding moulting cycles in bats when using fur for endogenous marker analysis. CAN J ZOOL 2013. [DOI: 10.1139/cjz-2013-0072] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Endogenous markers are a valuable indicator of individual animal ecology, but data interpretation requires a detailed understanding of the timing of tissue formation. Fur is commonly used in bat research using endogenous markers, but the moulting cycles of most bat species are not well documented. In this review, we (i) describe methods of investigating bat moulting; (ii) summarize the current literature on bat moulting cycles, highlighting broad trends; (iii) discuss knowledge gaps; and (iv) make recommendations for optimal fur sampling protocols. Three characteristics may indicate moulting in bats: changing skin pigmentation; visible fur growth and colour changes; and endogenous markers. Most studies reported new fur growth once annually during summer–fall, although there were exceptions. The timing of new fur growth varies among species, sexes, and age classes. Individuals commonly experience asynchronous new fur growth, with dorsal fur growth occurring before ventral. Specific moult progressions vary among species. Knowledge gaps include moulting cycles in tropical species and in subadult and yearling bats; migration during new fur growth; and the timing of fur growth compared with shedding. We recommend that fur samples taken dorsally from adult males are the most likely to be representative of the bat’s site of summer residency.
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Affiliation(s)
- E.E. Fraser
- Environmental Science (Biology), Memorial University of Newfoundland – Grenfell Campus, 20 University Drive, Corner Brook, NL A2H 5G4, Canada
| | - F.J. Longstaffe
- Department of Earth Sciences, The University of Western Ontario, London, ON N6A 5B7, Canada
| | - M.B. Fenton
- Department of Biology, The University of Western Ontario, London, ON N6A 5B7, Canada
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McGuire LP, Boyle WA. Altitudinal migration in bats: evidence, patterns, and drivers. Biol Rev Camb Philos Soc 2013; 88:767-86. [DOI: 10.1111/brv.12024] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2011] [Revised: 01/23/2013] [Accepted: 01/25/2013] [Indexed: 11/28/2022]
Affiliation(s)
- Liam P. McGuire
- Advanced Facility for Avian Research; Department of Biology; University of Western Ontario; 1151 Richmond Street North London Ontario N6A 5B7 Canada
| | - W. Alice Boyle
- Advanced Facility for Avian Research; Department of Biology; University of Western Ontario; 1151 Richmond Street North London Ontario N6A 5B7 Canada
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Gow EA, Stutchbury BJ, Done T, Kyser T. An examination of stable hydrogen isotope (δD) variation in adult and juvenile feathers from a migratory songbird. CAN J ZOOL 2012. [DOI: 10.1139/z2012-024] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Stable hydrogen isotopes (δD) can help predict geographic origin of tissue growth but within-site variation of feather δD (δDf) exists. Multiple hypotheses explain δDf variation: moult timing, physiology, and spatio-temporal differences in source deuterium, but there have been few direct tests of these factors. We assessed δDf variation within a breeding population of Wood Thrush ( Hylocichla mustelina (Gmelin, 1789)), by sampling feathers from hatch-year birds, returning adults (after migration), and to eliminate confounding variables from newly grown adult primary feathers during moult. We evaluated potential mechanisms explaining δDf variation by examining intraindividual variation (different feather types), precipitation δD, prey δD, corticosterone (CORT), and breeding productivity. In addition, we directly compared δDf of newly grown primary feathers to δD blood hematocrit (δDb). We found significant differences in δDf between years and age classes and observed no significant intraindividual variation. δDf and δDb were not significantly correlated. CORT weakly contributed to δDf, but there are other factors influencing δDf. Ten percent of all feather samples had outlying δDf values, and were likely grown away from the breeding grounds. Our results document intrapopulation and intraindividual variation of δDf at a single location and indicated that age class and year-to-year differences contributed to high δDf variance.
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Affiliation(s)
- Elizabeth A. Gow
- Department of Biology, York University, Toronto, ON M3J 1P3, Canada
| | | | - T. Done
- Department of Biology, York University, Toronto, ON M3J 1P3, Canada
| | - T.K. Kyser
- Department of Geological Sciences and Geological Engineering, Queen’s University, Kingston, ON K7L 3N6, Canada
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15
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Wunder MB. Determining geographic patterns of migration and dispersal using stable isotopes in keratins. J Mammal 2012. [DOI: 10.1644/11-mamm-s-182.1] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Fraser EE, McGuire LP, Eger JL, Longstaffe FJ, Fenton MB. Evidence of latitudinal migration in tri-colored bats, Perimyotis subflavus. PLoS One 2012; 7:e31419. [PMID: 22384019 PMCID: PMC3284490 DOI: 10.1371/journal.pone.0031419] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2011] [Accepted: 01/07/2012] [Indexed: 11/19/2022] Open
Abstract
Background Annual movements of tri-colored bats (Perimyotis subflavus) are poorly understood. While this species has been considered a regional migrant, some evidence suggests that it may undertake annual latitudinal migrations, similar to other long distance North American migratory bat species. Methodology/Principal Findings We investigated migration in P. subflavus by conducting stable hydrogen isotope analyses of 184 museum specimen fur samples and comparing these results (δDfur) to published interpolated δD values of collection site growing season precipitation (δDprecip). Results suggest that the male molt period occurred between June 23 and October 16 and 33% of males collected during the presumed non-molt period were south of their location of fur growth. For the same time period, 16% of females were south of their location of fur growth and in general, had not travelled as far as migratory males. There were strong correlations between δDfur from the presumed molt period and both growing season δDprecip (males – r2 = 0.86; p<0.01; females – r2 = 0.75; p<0.01), and latitude of collection (males – r2 = 0.85; p<0.01; females – r2 = 0.73; p<0.01). Most migrants were collected at the northern (>40°N; males and females) and southern (<35°N; males only) extents of the species' range. Conclusions/Significance These results indicate a different pattern of migration for this species than previously documented, suggesting that some P. subflavus engage in annual latitudinal migrations and that migratory tendency varies with latitude and between sexes. We suggest that this species' hibernation ecology makes it particularly susceptible to long winters, making migration from the northern extent of the species' range to more southern hibernacula preferable for some individuals. Fur δD values for some of the northern individuals may indicate an increase in the currently accepted northern range of this species. Sex-biased differences in migration may be the result of differences in reproductive pressures.
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Affiliation(s)
- Erin E Fraser
- Department of Biology, The University of Western Ontario, London, Ontario, Canada.
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A triple-isotope approach to predict the breeding origins of European bats. PLoS One 2012; 7:e30388. [PMID: 22291947 PMCID: PMC3264582 DOI: 10.1371/journal.pone.0030388] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2010] [Accepted: 12/15/2011] [Indexed: 11/30/2022] Open
Abstract
Despite a commitment by the European Union to protect its migratory bat populations, conservation efforts are hindered by a poor understanding of bat migratory strategies and connectivity between breeding and wintering grounds. Traditional methods like mark-recapture are ineffective to study broad-scale bat migratory patterns. Stable hydrogen isotopes (δD) have been proven useful in establishing spatial migratory connectivity of animal populations. Before applying this tool, the method was calibrated using bat samples of known origin. Here we established the potential of δD as a robust geographical tracer of breeding origins of European bats by measuring δD in hair of five sedentary bat species from 45 locations throughout Europe. The δD of bat hair strongly correlated with well-established spatial isotopic patterns in mean annual precipitation in Europe, and therefore was highly correlated with latitude. We calculated a linear mixed-effects model, with species as random effect, linking δD of bat hair to precipitation δD of the areas of hair growth. This model can be used to predict breeding origins of European migrating bats. We used δ13C and δ15N to discriminate among potential origins of bats, and found that these isotopes can be used as variables to further refine origin predictions. A triple-isotope approach could thereby pinpoint populations or subpopulations that have distinct origins. Our results further corroborated stable isotope analysis as a powerful method to delineate animal migrations in Europe.
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Erzberger A, Popa-Lisseanu AG, Lehmann GUC, Voigt CC. Potential and Limits in Detecting Altitudinal Movements of Bats using Stable Hydrogen Isotope Ratios of Fur Keratin. ACTA CHIROPTEROLOGICA 2011. [DOI: 10.3161/150811011x624910] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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The influence of microhabitat, moisture and diet on stable-hydrogen isotope variation in a Neotropical avian food web. JOURNAL OF TROPICAL ECOLOGY 2011. [DOI: 10.1017/s0266467411000332] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Abstract:The application of stable-hydrogen isotope (δD) measurements to the study of animal movement, resource use and physiology depends on understanding factors driving variation in δD in animal tissues. The source of micro-scale variation in δD is poorly known, yet understanding micro-scale patterns of δD could shed light on important ecological processes and improve our abilities to track animal movements. Using linear and additive models, we explored the influence of micro-scale habitat use, moisture and diet on tissue δD values of Nicaraguan cloud-forest birds. Using mist nets, we captured 211 individuals of 22 resident Neotropical species at 500–1390 m asl and collected feather and claw samples. Based on three years of data from year-round sampling, our results suggest that microhabitat, seasonal shifts in moisture δD, and diet all influence bird tissue δD values. Our model results reveal a previously undescribed microgeographical effect on δD, where foraging level (understorey versus overstorey) and foraging location (forest interior versus adjacent coffee plantation) were significant predictors of δD values in bird claws and feathers. Mean claw and feather δD values among species varied from −83‰ to −19‰. Top models for claws and feathers explained 57% and 52% of variation in δD respectively. Direct comparisons of understorey (mean ± SD of −30‰ ± 15‰) versus overstorey (−50‰ ± 15‰) claw values suggest that δD may be useful in tracking vertical, micro-scale movement. Higher δD values in forest understorey birds reveal a heavy reliance upon recycled, fog moisture. Fragmentation and climate change may result in increasingly desiccated cloud forest that may exert a more negative influence on the food webs of understorey species that seem to be supported by recycled sources of moisture in the dry season.
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