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Sagot M, Rose N, Chaverri G. Group vocal composition and decision-making during roost finding in Spix's disk-winged bats. Philos Trans R Soc Lond B Biol Sci 2024; 379:20230187. [PMID: 38768206 PMCID: PMC11391296 DOI: 10.1098/rstb.2023.0187] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 02/14/2024] [Accepted: 03/18/2024] [Indexed: 05/22/2024] Open
Abstract
Theoretical work suggests that having many informed individuals within social groups can promote efficient resource location. However, it may also give rise to group fragmentation if members fail to reach consensus on their direction of movement. In this study, we investigate whether the number of informed individuals, exemplified by bats emitting calls from different roosts, influences group cohesion in Spix's disk-winged bats (Thyroptera tricolor). Additionally, we explore the role of signal reliability, quantified through signalling rates, in group consensus on where to roost. These bats use contact calls to announce the location of a roost site and recruit conspecifics. The groups they form exhibit high levels of cohesion and consist of both vocal and non-vocal bats, with vocal behaviour being consistent over time. Our findings revealed that an increase in the number of roosts broadcasting calls is strongly associated with the likelihood of groups fragmenting among multiple roosts. Additionally, we found that a majority of group members enter the roost with higher calling rates. This phenomenon can mitigate the risk of group fragmentation, as bats emitting more calls may contribute to greater group consensus on roosting locations, thereby reducing the likelihood of individuals separating and enhancing overall group cohesion. Our results highlight the potential costs of having too many information producers for group coordination, despite their established role in finding critical resources. This article is part of the theme issue 'The power of sound: unravelling how acoustic communication shapes group dynamics'.
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Affiliation(s)
- Maria Sagot
- Department of Biological Sciences, State University of New York at Oswego , Oswego, NY 13126, USA
| | - Nicole Rose
- Department of Biological Sciences, State University of New York at Oswego , Oswego, NY 13126, USA
| | - Gloriana Chaverri
- Sede del Sur, Universidad de Costa Rica , Golfito 60701, Costa Rica
- Smithsonian Tropical Research Institute , Ancón, Panamá 0843-03092, Panama
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2
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Chaverri G, Sagot M, Stynoski JL, Araya-Salas M, Araya-Ajoy Y, Nagy M, Knörnschild M, Chaves-Ramírez S, Rose N, Sánchez-Chavarría M, Jiménez-Torres Y, Ulloa-Sanabria D, Solís-Hernández H, Carter GG. Calling to the collective: contact calling rates within groups of disc-winged bats do not vary by kinship or association. Philos Trans R Soc Lond B Biol Sci 2024; 379:20230195. [PMID: 38768198 PMCID: PMC11391311 DOI: 10.1098/rstb.2023.0195] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 12/16/2023] [Accepted: 02/23/2024] [Indexed: 05/22/2024] Open
Abstract
Many group-living animals coordinate social behaviours using contact calls, which can be produced for all group members or targeted at specific individuals. In the disc-winged bat, Thyroptera tricolor, group members use 'inquiry' and 'response' calls to coordinate daily movements into new roosts (furled leaves). Rates of both calls show consistent among-individual variation, but causes of within-individual variation remain unknown. Here, we tested whether disc-winged bats produce more contact calls towards group members with higher kinship or association. In 446 experimental trials, we recorded 139 random within-group pairs of one flying bat (producing inquiry calls for roost searching) and one roosting bat (producing response calls for roost advertising). Using generalized linear mixed-effect models (GLMM), we assessed how response and inquiry calling rates varied by sender, receiver, genetic kinship and co-roosting association rate. Calling rates varied consistently across senders but not by receiver. Response calling was influenced by inquiry calling rates, but neither calling rate was higher when the interacting pair had higher kinship or association. Rather than dyadic calling rates indicating within-group relationships, our findings are consistent with the hypothesis that bats produce contact calls to maintain contact with any or all individuals within a group while collectively searching for a new roost site. This article is part of the theme issue 'The power of sound: unravelling how acoustic communication shapes group dynamics'.
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Affiliation(s)
- Gloriana Chaverri
- Sede del Sur, Universidad de Costa Rica , 60701, Costa Rica
- Smithsonian Tropical Research Institute , 0843-03092, Panama
| | - Maria Sagot
- Department of Biological Sciences, State University of New York at Oswego , Oswego, NY 13126, USA
| | - Jennifer L Stynoski
- Instituto Clodomiro Picado, Universidad de Costa Rica , Coronado, San José 11103, Costa Rica
| | - Marcelo Araya-Salas
- Centro de Investigación en Neurociencias, Universidad de Costa Rica , San Pedro, San José 11501-2060, Costa Rica
- Escuela de Biología, Universidad de Costa Rica , , San José 11501-2060, Costa Rica
| | - Yimen Araya-Ajoy
- Department of Biology, Centre for Biodiversity Dynamics (CBD), Norwegian University of Science and Technology (NTNU) , , N-7491, Norway
| | - Martina Nagy
- Museum für Naturkunde, Leibniz-Institute for Evolution and Biodiversity Science , Berlin 10115, Germany
| | - Mirjam Knörnschild
- Museum für Naturkunde, Leibniz-Institute for Evolution and Biodiversity Science , Berlin 10115, Germany
| | - Silvia Chaves-Ramírez
- Programa de Posgrado en Biología, Universidad de Costa Rica , , San José 11501-2060, Costa Rica
| | - Nicole Rose
- Department of Biological Sciences, State University of New York at Oswego , Oswego, NY 13126, USA
| | - Mariela Sánchez-Chavarría
- Programa de Posgrado en Gestión Integrada de Áreas Costeras Tropicales, Universidad de Costa Rica , , San José 11501-2060, Costa Rica
| | | | | | | | - Gerald G Carter
- Smithsonian Tropical Research Institute , 0843-03092, Panama
- Department of Evolution, Ecology and Organismal Biology, The Ohio State University , Columbus, OH 43210, USA
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3
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Bat Use of Hollows in California’s Old-Growth Redwood Forests: From DNA to Ecology. Animals (Basel) 2022; 12:ani12212950. [DOI: 10.3390/ani12212950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 10/24/2022] [Accepted: 10/24/2022] [Indexed: 11/16/2022] Open
Abstract
The loss of roosting resources, either through disturbance or removal, negatively affects bats. Identifying sensitive species and determining roost requirements are critical components in conserving their habitat. Cavity-roosting bats on the North Coast of California are known to use hollows in large redwood trees. In this study, we examined the factors determining the use of basal tree hollows by different bat species at eight redwood forest sites in Del Norte, Humboldt, and Mendocino Counties, California. Bat guano was collected from 179 basal hollow roosts from 2017 to 2018, and guano mass was used as an index of roosting activity. Nine bat species and one species group were identified by analysis of DNA in guano. We made a total of 253 identifications from 83 hollows into the 10 species categories. The most prevalent species were Myotis californicus (California myotis; 28.5% of all identifications), the Myotis evotis-Myotis thysanodes group (17.4%), Corynorhinus townsendii (17.0%), and Myotis volans (15.0%). We evaluated the extent to which habitat variables at the scales of the hollow, vicinity, and site influenced the level of roost use. The correlations between guano mass and habitat variables were examined using generalized additive mixed models. At the hollow scale, guano mass increased with ceiling height above the opening. At the vicinity scale, guano mass increased with less cover of small trees. At the site scale, there was no association between guano mass and distance to foraging areas, elevation, or the number of nearby hollows. These tree hollow roost preferences can inform land managers when planning the management and conservation of redwood forests.
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4
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Maldonado‐Chaparro AA, Chaverri G. Why do animal groups matter for conservation and management? CONSERVATION SCIENCE AND PRACTICE 2021. [DOI: 10.1111/csp2.550] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Affiliation(s)
| | - Gloriana Chaverri
- Sede del Sur, Universidad de Costa Rica Golfito Costa Rica
- Smithsonian Tropical Research Institute Ancón Panama
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5
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Shute KE, Loeb SC, Jachowski DS. Summer Roosting Ecology of the Northern Yellow Bat and Tri-Colored Bat in Coastal South Carolina. SOUTHEAST NAT 2021. [DOI: 10.1656/058.020.0306] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Kyle E. Shute
- Department of Forestry and Environmental Conservation, Clemson University, Clemson, SC 29631
| | - Susan C. Loeb
- Southern Research Station, United States Forest Service, Clemson, SC 29631
| | - David S. Jachowski
- Department of Forestry and Environmental Conservation, Clemson University, Clemson, SC 29631
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6
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Garcés-Restrepo MF, Peery MZ, Pauli JN. The demography of a resource specialist in the tropics: Cecropia trees and the fitness of three-toed sloths. Proc Biol Sci 2020; 286:20182206. [PMID: 30963880 DOI: 10.1098/rspb.2018.2206] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Resource specialists persist in a narrow range of resources. Consequently, the abundance of key resources should drive vital rates, individual fitness, and population viability. While Neotropical forests feature both high levels of biodiversity and numbers of specialist species, no studies have directly evaluated how the variation of key resources affects the fitness of a tropical specialist. Here, we quantified the effect of key tree species density and forest cover on the fitness of three-toed sloths ( Bradypus variegatus), an arboreal folivore strongly associated with Cecropia trees in Costa Rica, using a multi-year demographic, genetic, and space-use dataset. We found that the density of Cecropia trees was strongly and positively related to both adult survival and reproductive output. A matrix model parametrized with Cecropia-demography relationships suggested positive growth of sloth populations, even at low densities of Cecropia (0.7 trees ha-1). Our study shows the first direct link between the density of a key resource to demographic consequences of a tropical specialist, underscoring the sensitivity of tropical specialists to the loss of a single key resource, but also point to targeted conservation measures to increase that resource. Finally, our study reveals that previously disturbed and regenerating environments can support viable populations of tropical specialists.
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Affiliation(s)
- Mario F Garcés-Restrepo
- Department of Forest and Wildlife Ecology, University of Wisconsin-Madison , 1630 Linden Drive, Madison, WI 53706 , USA
| | - M Zachariah Peery
- Department of Forest and Wildlife Ecology, University of Wisconsin-Madison , 1630 Linden Drive, Madison, WI 53706 , USA
| | - Jonathan N Pauli
- Department of Forest and Wildlife Ecology, University of Wisconsin-Madison , 1630 Linden Drive, Madison, WI 53706 , USA
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8
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Bondo KJ, Willis CKR, Metheny JD, Kilgour RJ, Gillam EH, Kalcounis‐Rueppell MC, Brigham RM. Bats relocate maternity colony after the natural loss of roost trees. J Wildl Manage 2019. [DOI: 10.1002/jwmg.21751] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Kristin J. Bondo
- University of Regina Department of Biology Regina SK S4S 0A2 Canada
| | | | - Jackie D. Metheny
- Department of BiologyUniversity of North Carolina at Greensboro Greensboro NC 27402‐6170 USA
| | - R. Julia Kilgour
- University of Regina Department of Biology Regina SK S4S 0A2 Canada
| | - Erin H. Gillam
- University of Regina Department of Biology Regina SK S4S 0A2 Canada
| | | | - R. M. Brigham
- University of Regina Department of Biology Regina SK S4S 0A2 Canada
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9
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Sagot M, Schöner CR, Jago AJ, Razik I, Chaverri G. The importance of group vocal behaviour in roost finding. Anim Behav 2018. [DOI: 10.1016/j.anbehav.2018.06.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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10
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Geographic variation of contact calls suggest distinct modes of vocal transmission in a leaf-roosting bat. Behav Ecol Sociobiol 2018. [DOI: 10.1007/s00265-018-2543-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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11
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Bohn K, Gillam E. In-flight social calls: a primer for biologists and managers studying echolocation. CAN J ZOOL 2018. [DOI: 10.1139/cjz-2017-0188] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Recent technological advances have permitted collection of immense data sets through automated recordings that are primarily aimed at capturing bat echolocation. Analyses of echolocation calls are used to identify species, relative abundance, and some aspects of behaviour, such as foraging or commuting. Here we propose that social calls recorded in flight are also valuable tools for understanding bat ecology and behaviour. First, we examine how and why the acoustic structure of social calls differ from echolocation. Differences in form make social calls often, but not always, easy to identify. We then use a case study on in-flight song in Brazilian free-tailed bat (Tadarida brasiliensis (I. Geoffroy, 1824)) to show that what may appear as echolocation may instead be predominantly used for social communication. Next, we review three basic functions of in-flight social calls, including examples of each, and develop a framework for testing these alternative functions using automated recordings. In a second case study, we use automated recordings of the endangered Florida bonneted bat (Eumops floridanus (G.M. Allen, 1932)) to illustrate how behavioural information can be gleaned by examining patterns of social call production. Finally, we discuss why and how social calls provide novel information that can be crucial for conservation and management efforts.
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Affiliation(s)
- K.M. Bohn
- Department of Psychological and Brain Sciences, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21211, USA
| | - E.H. Gillam
- Department of Biological Sciences, North Dakota State University, 218 Stevens Hall, Fargo, ND 58102, USA
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12
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Affiliation(s)
- Bryan D. Watts
- The Center for Conservation BiologyCollege of William and Mary and Virginia Commonwealth UniversityP.O. Box 8795WilliamsburgVA 23187USA
| | - Rodney J. Dyer
- Department of BiologyVirginia Commonwealth University1000 W Cary StreetRichmondVA 23284‐2012USA
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13
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Chaverri G, Ancillotto L, Russo D. Social communication in bats. Biol Rev Camb Philos Soc 2018; 93:1938-1954. [PMID: 29766650 DOI: 10.1111/brv.12427] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Revised: 04/19/2018] [Accepted: 04/25/2018] [Indexed: 11/30/2022]
Abstract
Bats represent one of the most diverse mammalian orders, not only in terms of species numbers, but also in their ecology and life histories. Many species are known to use ephemeral and/or unpredictable resources that require substantial investment to find and defend, and also engage in social interactions, thus requiring significant levels of social coordination. To accomplish these tasks, bats must be able to communicate; there is now substantial evidence that demonstrates the complexity of bat communication and the varied ways in which bats solve some of the problems associated with their unique life histories. However, while the study of communication in bats is rapidly growing, it still lags behind other taxa. Here we provide a comprehensive overview of communication in bats, from the reasons why they communicate to the diversity and application of different signal modalities. The most widespread form of communication is the transmission of a signaller's characteristics, such as species identity, sex, individual identity, group membership, social status and body condition, and because many species of bats can rely little on vision due to their nocturnal lifestyles, it is assumed that sound and olfaction are particularly important signalling modes. For example, research suggests that secretions from specialized glands, often in combination with urine and saliva, are responsible for species recognition in several species. These olfactory signals may also convey information about sex and colony membership. Olfaction may be used in combination with sound, particularly in species that emit constant frequency (CF) echolocation calls, to recognize conspecifics from heterospecifics, yet their simple structure and high frequency do not allow much information of individual identity to be conveyed over long distances. By contrast, social calls may encode a larger number of cues of individual identity, and their lower frequencies increase their range of detection. Social calls are also known to deter predators, repel competitors from foraging patches, attract group mates to roost sites, coordinate foraging activities, and are used during courtship. In addition to sound, visual displays such as wing flapping or hovering may be used during courtship, and swarming around roost sites may serve as a visual cue of roost location. However, visual communication in bats still remains a poorly studied signal modality. Finally, the most common form of tactile communication known in bats is social grooming, which may be used to signal reproductive condition, but also to facilitate and strengthen cooperative interactions. Overall, this review demonstrates the rapid advances made in the study of bat social communication during recent years, and also identifies topics that require further study, particularly those that may allow us to understand adaptation to rapidly changing environmental conditions.
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Affiliation(s)
- Gloriana Chaverri
- Recinto de Golfito, Universidad de Costa Rica, Golfito, 60701, Costa Rica
| | - Leonardo Ancillotto
- Wildlife Research Unit, Dipartimento di Agraria, Università degli Studi di Napoli Federico II, via Università 100, Portici NA 80055, Italy
| | - Danilo Russo
- Wildlife Research Unit, Dipartimento di Agraria, Università degli Studi di Napoli Federico II, via Università 100, Portici NA 80055, Italy.,School of Biological Sciences, University of Bristol, 24 Tyndall Avenue, Bristol BS8 1TQ, U.K
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14
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Restoration of Legacy Trees as Roosting Habitat for Myotis Bats in Eastern North American Forests. DIVERSITY 2018. [DOI: 10.3390/d10020029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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15
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Schöner MG, Schöner CR, Kerth G, Ji LL, Grafe TU. Bats Attend to Plant Structures to Identify Roosting Sites. ACTA CHIROPTEROLOGICA 2016. [DOI: 10.3161/15081109acc2016.18.2.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Michael G. Schöner
- Zoological Institute and Museum, University of Greifswald, J.-S.-Bach-Strasse 11/12, 17489 Greifswald, Germany
| | - Caroline R. Schöner
- Zoological Institute and Museum, University of Greifswald, J.-S.-Bach-Strasse 11/12, 17489 Greifswald, Germany
| | - Gerald Kerth
- Zoological Institute and Museum, University of Greifswald, J.-S.-Bach-Strasse 11/12, 17489 Greifswald, Germany
| | - Liaw Lin Ji
- Faculty of Science, University Brunei Darussalam, Tungku Link, Gadong 1410, Brunei Darussalam
| | - T. Ulmar Grafe
- Faculty of Science, University Brunei Darussalam, Tungku Link, Gadong 1410, Brunei Darussalam
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Monks JM, O'Donnell CFJ. Social implications of a colony collapse in a highly structured vertebrate species (long-tailed bat, Chalinolobus tuberculatus
). Anim Conserv 2016. [DOI: 10.1111/acv.12324] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- J. M. Monks
- Science and Policy Group; Department of Conservation; P O Box 5244 Dunedin New Zealand
| | - C. F. J. O'Donnell
- Science and Policy Group; Department of Conservation; Private Bag 4715; Christchurch Mail Centre; Christchurch New Zealand
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17
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Affiliation(s)
- Sandrine Pavoine
- Centre d'Ecologie et des Sciences de la Conservation (CESCO UMR7204); Sorbonne Universités; MNHN, CNRS, UPMC, CP51, 55-61 rue Buffon FR-75005 Paris France
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Sagot M, Chaverri G. Effects of roost specialization on extinction risk in bats. CONSERVATION BIOLOGY : THE JOURNAL OF THE SOCIETY FOR CONSERVATION BIOLOGY 2015; 29:1666-1673. [PMID: 26081600 DOI: 10.1111/cobi.12546] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Accepted: 03/21/2015] [Indexed: 06/04/2023]
Abstract
Understanding causes and consequences of ecological specialization is of major concern in conservation. Specialist species are particularly vulnerable to human activities. If their food or habitats are depleted or lost, they may not be able to exploit alternative resources, and population losses may result. We examined International Union for Conservation of Nature (IUCN) Red List bat data and the number of roosts used per species (accounting for phylogenetic independence) to determine whether roost specialization is correlated with extinction risk. We found a significant correlation between the IUCN Red List category and the number of roost types used. Species that use fewer roost types had a higher risk of extinction. We found that caves and similar structures were the most widely used roost types, particularly by species under some level of risk of extinction. Many critically endangered, endangered, or vulnerable species used natural roosts exclusively, whereas less threatened species used natural and human-made roosts. Our results suggest that roost loss, particularly in species that rely on a single roost type, may be linked to extinction risk. Our focus on a single life history trait prevented us from determining how important this variable is for extinction risk relative to other variables, but we have taken a first step toward prioritizing conservation actions. Our results also suggest that roost specialization may exacerbate population declines due to other risk factors, such as hunting pressure or habitat loss, and thus that management actions to preserve species under risk of extinction should prioritize protection of roosting sites.
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Affiliation(s)
- Maria Sagot
- Department of Biological Sciences, State University of New York at Oswego, Oswego, NY, 13126, U.S.A..
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19
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Behavioural strategies associated with using an ephemeral roosting resource in Spix's disc-winged bat. Anim Behav 2015. [DOI: 10.1016/j.anbehav.2015.07.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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20
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Silvis A, Ford WM, Britzke ER. Effects of hierarchical roost removal on northern long-eared bat (Myotis septentrionalis) maternity colonies. PLoS One 2015; 10:e0116356. [PMID: 25611060 PMCID: PMC4303276 DOI: 10.1371/journal.pone.0116356] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Accepted: 11/20/2014] [Indexed: 12/04/2022] Open
Abstract
Forest roosting bats use a variety of ephemeral roosts such as snags and declining live trees. Although conservation of summer maternity habitat is considered critical for forest-roosting bats, bat response to roost loss still is poorly understood. To address this, we monitored 3 northern long-eared bat (Myotis septentrionalis) maternity colonies on Fort Knox Military Reservation, Kentucky, USA, before and after targeted roost removal during the dormant season when bats were hibernating in caves. We used 2 treatments: removal of a single highly used (primary) roost and removal of 24% of less used (secondary) roosts, and an un-manipulated control. Neither treatment altered the number of roosts used by individual bats, but secondary roost removal doubled the distances moved between sequentially used roosts. However, overall space use by and location of colonies was similar pre- and post-treatment. Patterns of roost use before and after removal treatments also were similar but bats maintained closer social connections after our treatments. Roost height, diameter at breast height, percent canopy openness, and roost species composition were similar pre- and post-treatment. We detected differences in the distribution of roosts among decay stages and crown classes pre- and post-roost removal, but this may have been a result of temperature differences between treatment years. Our results suggest that loss of a primary roost or ≤ 20% of secondary roosts in the dormant season may not cause northern long-eared bats to abandon roosting areas or substantially alter some roosting behaviors in the following active season when tree-roosts are used. Critically, tolerance limits to roost loss may be dependent upon local forest conditions, and continued research on this topic will be necessary for conservation of the northern long-eared bat across its range.
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Affiliation(s)
- Alexander Silvis
- Department of Fish and Wildlife Conservation, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, United States of America
- * E-mail:
| | - W. Mark Ford
- Department of Fish and Wildlife Conservation, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, United States of America
- US Geological Survey, Virginia Cooperative Fish and Wildlife Research Unit, Blacksburg, Virginia, United States of America
| | - Eric R. Britzke
- US Army Engineer Research and Development Center, Environmental Laboratory, Vicksburg, Mississippi, United States of America
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Silvis A, Kniowski AB, Gehrt SD, Ford WM. Roosting and foraging social structure of the endangered Indiana bat (Myotis sodalis). PLoS One 2014; 9:e96937. [PMID: 24816811 PMCID: PMC4016147 DOI: 10.1371/journal.pone.0096937] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Accepted: 04/13/2014] [Indexed: 11/18/2022] Open
Abstract
Social dynamics are an important but poorly understood aspect of bat ecology. Herein we use a combination of graph theoretic and spatial approaches to describe the roost and social network characteristics and foraging associations of an Indiana bat (Myotis sodalis) maternity colony in an agricultural landscape in Ohio, USA. We tracked 46 bats to 50 roosts (423 total relocations) and collected 2,306 foraging locations for 40 bats during the summers of 2009 and 2010. We found the colony roosting network was highly centralized in both years and that roost and social networks differed significantly from random networks. Roost and social network structure also differed substantially between years. Social network structure appeared to be unrelated to segregation of roosts between age classes. For bats whose individual foraging ranges were calculated, many shared foraging space with at least one other bat. Compared across all possible bat dyads, 47% and 43% of the dyads showed more than expected overlap of foraging areas in 2009 and 2010 respectively. Colony roosting area differed between years, but the roosting area centroid shifted only 332 m. In contrast, whole colony foraging area use was similar between years. Random roost removal simulations suggest that Indiana bat colonies may be robust to loss of a limited number of roosts but may respond differently from year to year. Our study emphasizes the utility of graphic theoretic and spatial approaches for examining the sociality and roosting behavior of bats. Detailed knowledge of the relationships between social and spatial aspects of bat ecology could greatly increase conservation effectiveness by allowing more structured approaches to roost and habitat retention for tree-roosting, socially-aggregating bat species.
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Affiliation(s)
- Alexander Silvis
- Department of Fish and Wildlife Conservation, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, United States of America
- * E-mail:
| | - Andrew B. Kniowski
- Department of Fish and Wildlife Conservation, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, United States of America
| | - Stanley D. Gehrt
- School of Environment and Natural Resources, The Ohio State University, Columbus, Ohio, United States of America
| | - W. Mark Ford
- Department of Fish and Wildlife Conservation, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, United States of America
- U.S. Geological Survey, Virginia Cooperative Fish and Wildlife Research Unit, Department of Fish and Wildlife Conservation, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, United States of America
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Silvis A, Ford WM, Britzke ER, Johnson JB. Association, roost use and simulated disruption of Myotis septentrionalis maternity colonies. Behav Processes 2014; 103:283-90. [DOI: 10.1016/j.beproc.2014.01.016] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Revised: 12/18/2013] [Accepted: 01/04/2014] [Indexed: 11/29/2022]
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Borkin KM, Parsons S. Effects of clear-fell harvest on bat home range. PLoS One 2014; 9:e86163. [PMID: 24465938 PMCID: PMC3899175 DOI: 10.1371/journal.pone.0086163] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2013] [Accepted: 12/06/2013] [Indexed: 11/18/2022] Open
Abstract
We investigated effects of roost loss due to clear-fell harvest on bat home range. The study took place in plantation forest, inhabited by the New Zealand long-tailed bat (Chalinolobus tuberculatus), in which trees are harvested between the ages 26-32 years. We determined home ranges by radiotracking different bats in areas that had and had not been recently clear-fell harvested. Home ranges were smaller in areas that had been harvested. Adult male bats selected 20-25 year old stands within home ranges before and after harvest. Males selected edges with open unplanted areas when harvest had not occurred but no longer selected these at proportions greater than their availability post harvest, probably because they were then readily available. This is the first radiotracking study to demonstrate a change in home range size and selection concomitant with felling of large areas of plantation forest, and thus quantify negative effects of forestry operations on this speciose group. The use of smaller home ranges post-harvest may reflect smaller colony sizes and lower roost availability, both of which may increase isolation of colonies and vulnerability to local extinction.
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Affiliation(s)
- Kerry M. Borkin
- School of Biological Sciences, University of Auckland, Auckland, New Zealand
| | - Stuart Parsons
- School of Biological Sciences, University of Auckland, Auckland, New Zealand
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Velazco PM, Gregorin R, Voss RS, Simmons NB. Extraordinary Local Diversity of Disk-Winged Bats (Thyropteridae:Thyroptera) in Northeastern Peru, with the Description of a New Species and Comments on Roosting Behavior. AMERICAN MUSEUM NOVITATES 2014. [DOI: 10.1206/3795.1] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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25
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Buchalski MR, Chaverri G, Vonhof MJ. When genes move farther than offspring: gene flow by male gamete dispersal in the highly philopatric bat species Thyroptera tricolor. Mol Ecol 2013; 23:464-80. [PMID: 24237721 DOI: 10.1111/mec.12593] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2013] [Revised: 10/29/2013] [Accepted: 11/08/2013] [Indexed: 11/29/2022]
Abstract
For species characterized by philopatry of both sexes, mate selection represents an important behaviour for inbreeding avoidance, yet the implications for gene flow are rarely quantified. Here, we present evidence of male gamete-mediated gene flow resulting from extra-group mating in Spix's disc-winged bat, Thyroptera tricolor, a species which demonstrates all-offspring philopatry. We used microsatellite and capture-recapture data to characterize social group structure and the distribution of mated pairs at two sites in southwestern Costa Rica over four breeding seasons. Relatedness and genetic spatial autocorrelation analyses indicated strong kinship within groups and over short distances (<50 m), resulting from matrilineal group structure and small roosting home ranges (~0.2 ha). Despite high relatedness among-group members, observed inbreeding coefficients were low (FIS = 0.010 and 0.037). Parentage analysis indicated mothers and offspring belonged to the same social group, while fathers belonged to different groups, separated by large distances (~500 m) when compared to roosting home ranges. Simulated random mating indicated mate choice was not based on intermediate levels of relatedness, and mated pairs were less related than adults within social groups on average. Isolation-by-distance (IBD) models of genetic neighbourhood area based on father-offspring distances provided direct estimates of mean gamete dispersal distances (r^) > 10 roosting home range equivalents. Indirect estimates based on genetic distance provided even larger estimates of r^, indicating direct estimates were biased low. These results suggest extra-group mating reduces the incidence of inbreeding in T. tricolor, and male gamete dispersal facilitates gene flow in lieu of natal dispersal of young.
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Affiliation(s)
- M R Buchalski
- Department of Biological Sciences, Western Michigan University, Kalamazoo, MI, 49008, USA.,Veterinary Genetics Laboratory, University of California, Davis, Davis, CA, 95616, USA
| | - G Chaverri
- Universidad de Costa Rica, Golfito, 60701, Costa Rica
| | - M J Vonhof
- Department of Biological Sciences, Western Michigan University, Kalamazoo, MI, 49008, USA
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Chaverri G, Gillam EH. Sound amplification by means of a horn-like roosting structure in Spix's disc-winged bat. Proc Biol Sci 2013; 280:20132362. [PMID: 24132312 DOI: 10.1098/rspb.2013.2362] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
While sound is a signal modality widely used by many animals, it is very susceptible to attenuation, hampering effective long-distance communication. A strategy to minimize sound attenuation that has been historically used by humans is to use acoustic horns; to date, no other animal is known to use a similar structure to increase sound intensity. Here, we describe how the use of a roosting structure that resembles an acoustic horn (the tapered tubes that form when new leaves of plants such as Heliconia or Calathea species start to unfurl) increases sound amplification of the incoming and outgoing social calls used by Spix's disc-winged bat (Thyroptera tricolor) to locate roosts and group members. Our results indicate that incoming calls are significantly amplified as a result of sound waves being increasingly compressed as they move into the narrow end of the leaf. Outgoing calls were faintly amplified, probably as a result of increased sound directionality. Both types of call, however, experienced significant sound distortion, which might explain the patterns of signal recognition previously observed in behavioural experiments. Our study provides the first evidence of the potential role that a roost can play in facilitating acoustic communication in bats.
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Affiliation(s)
- Gloriana Chaverri
- Universidad de Costa Rica, , Alamedas, Golfito 60701, Costa Rica, Department of Biological Sciences, North Dakota State University, , Fargo, ND 58108, USA
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27
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Chaverri G, Gillam EH, Kunz TH. A call-and-response system facilitates group cohesion among disc-winged bats. Behav Ecol 2012. [DOI: 10.1093/beheco/ars188] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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