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Dytkowicz M, Hinds R, Megill WM, Buttschardt TK, Rosell F. A camera trapping method for the targeted capture of Eurasian beaver (Castor fiber) tails for individual scale pattern recognition. EUR J WILDLIFE RES 2023. [DOI: 10.1007/s10344-023-01654-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/31/2023]
Abstract
Abstract
Camera traps are commonly used to monitor and study wild animals in their natural habitat, with minimal disturbance. Several investigations have shown that the natural markings of animals for some species can be used for individual recognition. However, most commercially available cameras are unable to obtain photos of sufficient quality to highlight these features. Our study further exemplifies the use of applying an external lens to a camera, to obtain higher quality images. We tested various lenses and their ability to record the scale patterns on Eurasian beaver (Castor fiber) tails, for individual identification. We tested eleven different commercially available camera trap models, across six different beaver territories in the Districts of Kleve and Wesel (North Rhine-Westphalia, Germany). The use of an external lens, attached to the camera, produced the best quality pictures for reliable identification of individual beavers based on the scale patterns on their tales. These results further exemplify the application of external lenses for improving image quality for individual recognition which has potential applications for other species.
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Frauendorf M, Allen AM, Jongejans E, Ens BJ, Teunissen W, Kampichler C, Turnhout CAM, Bailey LD, Kroon H, Cremer J, Kleyheeg E, Nienhuis J, Pol M. Love thy neighbour?—Spatial variation in density dependence of nest survival in relation to predator community. DIVERS DISTRIB 2022. [DOI: 10.1111/ddi.13457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Affiliation(s)
- Magali Frauendorf
- Department of Animal Ecology Netherlands Institute of Ecology Wageningen The Netherlands
- Radboud Institute for Biological and Environmental Sciences Radboud University Nijmegen The Netherlands
- Centre for Avian Population Studies Wageningen The Netherlands
| | - Andrew M. Allen
- Department of Animal Ecology Netherlands Institute of Ecology Wageningen The Netherlands
- Radboud Institute for Biological and Environmental Sciences Radboud University Nijmegen The Netherlands
- Centre for Avian Population Studies Wageningen The Netherlands
| | - Eelke Jongejans
- Department of Animal Ecology Netherlands Institute of Ecology Wageningen The Netherlands
- Radboud Institute for Biological and Environmental Sciences Radboud University Nijmegen The Netherlands
- Centre for Avian Population Studies Wageningen The Netherlands
| | - Bruno J. Ens
- Centre for Avian Population Studies Wageningen The Netherlands
- Sovon – Dutch Centre for Field Ornithology Nijmegen The Netherlands
| | - Wolf Teunissen
- Centre for Avian Population Studies Wageningen The Netherlands
- Sovon – Dutch Centre for Field Ornithology Nijmegen The Netherlands
| | - Christian Kampichler
- Centre for Avian Population Studies Wageningen The Netherlands
- Sovon – Dutch Centre for Field Ornithology Nijmegen The Netherlands
| | - Chris A. M. Turnhout
- Radboud Institute for Biological and Environmental Sciences Radboud University Nijmegen The Netherlands
- Centre for Avian Population Studies Wageningen The Netherlands
- Sovon – Dutch Centre for Field Ornithology Nijmegen The Netherlands
| | - Liam D. Bailey
- Department of Evolutionary Genetics Leibniz Institute for Zoo and Wildlife Research Berlin Germany
| | - Hans Kroon
- Radboud Institute for Biological and Environmental Sciences Radboud University Nijmegen The Netherlands
- Centre for Avian Population Studies Wageningen The Netherlands
| | - Jenny Cremer
- Wageningen Marine Research Wageningen University & Research Den Helder The Netherlands
| | - Erik Kleyheeg
- Centre for Avian Population Studies Wageningen The Netherlands
- Sovon – Dutch Centre for Field Ornithology Nijmegen The Netherlands
| | - Jeroen Nienhuis
- Centre for Avian Population Studies Wageningen The Netherlands
- Sovon – Dutch Centre for Field Ornithology Nijmegen The Netherlands
| | - Martijn Pol
- Department of Animal Ecology Netherlands Institute of Ecology Wageningen The Netherlands
- Centre for Avian Population Studies Wageningen The Netherlands
- College of Science and Engineering James Cook University Townsville Qld Australia
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3
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Robstad CA, Lodberg-Holm HK, Mayer M, Rosell F. The impact of bio-logging on body weight change of the Eurasian beaver. PLoS One 2021; 16:e0261453. [PMID: 34941892 PMCID: PMC8699976 DOI: 10.1371/journal.pone.0261453] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Accepted: 12/02/2021] [Indexed: 11/23/2022] Open
Abstract
Bio-logging is a common method to collect ecological data on wild animals, but might also induce stress, reduce body condition, and alter behavior. Eurasian beavers (Castor fiber) are a semi-aquatic and nocturnal species that are challenging to observe in the wild. Bio-loggers are hence useful tools to study their behaviour and movements, but this raises concerns of potential negative impacts of tagging. To investigate the potential negative impacts of glue-on tags, we compared body weight change for tagged and untagged Eurasian beavers. We hypothesized that tagged beavers would gain less body weight compared to untagged beavers, and that weight change might be affected by tagging length, tag weight, water temperature and the season of tagging. Daily percentage body weight change in relation to initial body weight during the first capture was compared during 57 tagging periods (18±7 days) and 32 controls periods (64±47 days). Body weight change varied between the two groups, with untagged beavers on average gaining daily weight whilst tagged beavers on average lost weight daily, indicating a negative effect of tagging. The average reduction in percentage body weight change per day for tagged beavers was small (0.1 ± 0.3%), and with large individual variation. Neither tag weight, number of tagging days, nor season were important in explaining body weight change of tagged animals. In other words, we found that tagging reduced daily body weight during the tagging period but were unable to determine the mechanism(s) responsible for this decline. Detrimental effects of tagging have important implications for animal welfare and can introduce bias in data that are collected. This calls for careful consideration in the use of tags. We conclude that studies investigating the effects of tagging should consider individual variation in the effects of tagging and, where possible, compare tagged animals with a control group.
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Affiliation(s)
- Christian Andre Robstad
- Faculty of Technology, Natural Sciences and Maritime Sciences, Department of Natural Sciences and Environmental Health, University of South-Eastern Norway, Notodden, Norway
| | - Hanna Kavli Lodberg-Holm
- Faculty of Technology, Natural Sciences and Maritime Sciences, Department of Natural Sciences and Environmental Health, University of South-Eastern Norway, Notodden, Norway
| | - Martin Mayer
- Faculty of Technology, Natural Sciences and Maritime Sciences, Department of Natural Sciences and Environmental Health, University of South-Eastern Norway, Notodden, Norway
- Department of Bioscience, Aarhus University, Rønde, Denmark
| | - Frank Rosell
- Faculty of Technology, Natural Sciences and Maritime Sciences, Department of Natural Sciences and Environmental Health, University of South-Eastern Norway, Notodden, Norway
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4
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Nimje PS, Mayer M, Zedrosser A, Sæbø M, Rosell F. Territory acquisition and mate choice in a monogamous mammal, the Eurasian beaver. Anim Behav 2021. [DOI: 10.1016/j.anbehav.2021.06.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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5
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Moss JB, While GM. The thermal environment as a moderator of social evolution. Biol Rev Camb Philos Soc 2021; 96:2890-2910. [PMID: 34309173 DOI: 10.1111/brv.12784] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 07/09/2021] [Accepted: 07/16/2021] [Indexed: 11/29/2022]
Abstract
Animal sociality plays a crucial organisational role in evolution. As a result, understanding the factors that promote the emergence, maintenance, and diversification of animal societies is of great interest to biologists. Climate is among the foremost ecological factors implicated in evolutionary transitions in social organisation, but we are only beginning to unravel the possible mechanisms and specific climatic variables that underlie these associations. Ambient temperature is a key abiotic factor shaping the spatio-temporal distribution of individuals and has a particularly strong influence on behaviour. Whether such effects play a broader role in social evolution remains to be seen. In this review, we develop a conceptual framework for understanding how thermal effects integrate into pathways that mediate the opportunities, nature, and context of social interactions. We then implement this framework to discuss the capacity for temperature to initiate organisational changes across three broad categories of social evolution: group formation, group maintenance, and group elaboration. For each category, we focus on pivotal traits likely to have underpinned key social transitions and explore the potential for temperature to affect changes in these traits by leveraging empirical examples from the literature on thermal and behavioural ecology. Finally, we discuss research directions that should be prioritised to understand the potentially constructive and/or destructive effects of future warming on the origins, maintenance, and diversification of animal societies.
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Affiliation(s)
- Jeanette B Moss
- School of Natural Sciences, University of Tasmania, Sandy Bay, TAS, 7005, Australia
| | - Geoffrey M While
- School of Natural Sciences, University of Tasmania, Sandy Bay, TAS, 7005, Australia
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Horníček J, Šimůnková K, Mokrý J, Korbelová J, Vorel A. How Do the Beaver Home Ranges Vary during the Range Expansion? ANN ZOOL FENN 2021. [DOI: 10.5735/086.059.0102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Jan Horníček
- Department of Ecology, Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Kamýcká 129,, CZ-16521 Prague 6, Czech Republic
| | - Kamila Šimůnková
- Department of Ecology, Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Kamýcká 129,, CZ-16521 Prague 6, Czech Republic
| | - Jan Mokrý
- Department of Research and Nature Protection, Šumava National Park Administration, Sušická 399, CZ-34192 Kašperské Hory, Czech Republic
| | - Jana Korbelová
- Department of Ecology, Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Kamýcká 129,, CZ-16521 Prague 6, Czech Republic
| | - Aleš Vorel
- Department of Ecology, Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Kamýcká 129,, CZ-16521 Prague 6, Czech Republic
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7
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Size is not everything: differing activity and foraging patterns between the sexes in a monomorphic mammal. Behav Ecol Sociobiol 2021. [DOI: 10.1007/s00265-021-03010-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Abstract
Animals balance foraging with other activities, and activity patterns may differ between sexes due to differing physical requirements and reproductive investments. Sex-specific behavioural differences are common in sexually dimorphic mammals, but have received limited research attention in monomorphic mammals where the sexes are similar in body size. Eurasian beavers (Castor fiber) are obligate monogamous and monomorphic mammals and a good model species to study sex-specific differences. As females increase energy expenditure during reproduction, we hypothesized differing seasonal activity budgets, circadian activity rhythms and foraging patterns between male and reproducing female beavers. To test this hypothesis, we equipped adult beavers with VHF transmitters (N=41; 16 female, 25 male) and observed them throughout their active period at night from spring to late summer. Occurrence of their main activities (foraging, travelling and being in lodge) and use of food items (trees/shrubs, aquatic vegetation and herbs/grasses) were modelled to investigate sex-specific seasonal activity budgets and circadian activity rhythms. The sexes did not differ in time spent foraging across the season or night, but during spring, females resided more in the lodge and travelled less. Males and females both foraged on aquatic vegetation during spring, but females used this food source also during late summer, whereas males mostly foraged on trees/shrubs throughout the year. We conclude that seasonal activity budgets and foraging differ subtly between the sexes, which may relate to different energy budgets associated with reproduction and nutritional requirements. Such subtle seasonal behavioural adaptions may be vital for survival and reproduction of monomorphic species.
Significance statement
Activity budgets and foraging patterns of animals are key to their survival and may differ between males and females with different body sizes and physical requirements. In monomorphic species, where males and females have similar body sizes, fewer differences are expected, but may still be pronounced during certain times of the year. We modelled sex-specific seasonal activity budgets and circadian activity rhythms and use of food items in a monomorphic mammal, the Eurasian beaver. By treating season and time of day as a continuous variable rather than modelling differences within distinct predefined periods, we identified subtle sex-specific seasonal trends in activity budgets and use of food items.
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Johnson‐Bice SM, Ferguson JM, Erb JD, Gable TD, Windels SK. Ecological forecasts reveal limitations of common model selection methods: predicting changes in beaver colony densities. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2021; 31:e02198. [PMID: 32583507 PMCID: PMC7816246 DOI: 10.1002/eap.2198] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2019] [Revised: 03/13/2020] [Accepted: 03/30/2020] [Indexed: 05/20/2023]
Abstract
Over the past two decades, there have been numerous calls to make ecology a more predictive science through direct empirical assessments of ecological models and predictions. While the widespread use of model selection using information criteria has pushed ecology toward placing a higher emphasis on prediction, few attempts have been made to validate the ability of information criteria to correctly identify the most parsimonious model with the greatest predictive accuracy. Here, we used an ecological forecasting framework to test the ability of information criteria to accurately predict the relative contribution of density dependence and density-independent factors (forage availability, harvest, weather, wolf [Canis lupus] density) on inter-annual fluctuations in beaver (Castor canadensis) colony densities. We modeled changes in colony densities using a discrete-time Gompertz model, and assessed the performance of four models using information criteria values: density-independent models with (1) and without (2) environmental covariates; and density-dependent models with (3) and without (4) environmental covariates. We then evaluated the forecasting accuracy of each model by withholding the final one-third of observations from each population and compared observed vs. predicted densities. Information criteria and our forecasting accuracy metrics both provided strong evidence of compensatory density dependence in the annual dynamics of beaver colony densities. However, despite strong within-sample performance by the most complex model (density-dependent with covariates) as determined using information criteria, hindcasts of colony densities revealed that the much simpler density-dependent model without covariates performed nearly as well predicting out-of-sample colony densities. The hindcast results indicated that the complex model over-fit our data, suggesting that parameters identified by information criteria as important predictor variables are only marginally valuable for predicting landscape-scale beaver colony dynamics. Our study demonstrates the importance of evaluating ecological models and predictions with long-term data and revealed how a known limitation of information criteria (over-fitting of complex models) can affect our interpretation of ecological dynamics. While incorporating knowledge of the factors that influence animal population dynamics can improve population forecasts, we suggest that comparing forecast performance metrics can likewise improve our knowledge of the factors driving population dynamics.
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Affiliation(s)
- Sean M. Johnson‐Bice
- Department of Biological SciencesUniversity of Manitoba50 Sifton RoadWinnipegManitobaR3T 2N2Canada
- Natural Resources Research InstituteUniversity of Minnesota Duluth5013 Miller Trunk HighwayDuluthMinnesota55812USA
| | - Jake M. Ferguson
- Department of BiologyUniversity of Hawai`i at Mānoa2538 McCarthy MallHonoluluHawaii96822USA
| | - John D. Erb
- Forest Wildlife Populations and Research GroupMinnesota Department of Natural Resources1201 E. highway 2Grand RapidsMinnesota55744USA
| | - Thomas D. Gable
- Department of Fisheries, Wildlife and Conservation BiologyUniversity of Minnesota Twin Cities2003 Upper Buford CircleSt. PaulMinnesota55108USA
| | - Steve K. Windels
- Natural Resources Research InstituteUniversity of Minnesota Duluth5013 Miller Trunk HighwayDuluthMinnesota55812USA
- Department of Fisheries, Wildlife and Conservation BiologyUniversity of Minnesota Twin Cities2003 Upper Buford CircleSt. PaulMinnesota55108USA
- Voyageurs National Park360 Highway 11 E.International FallsMinnesota56649USA
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9
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Veitch JSM, Bowman J, Mastromonaco G, Schulte-Hostedde AI. Corticosterone response by Peromyscus mice to parasites, reproductive season, and age. Gen Comp Endocrinol 2021; 300:113640. [PMID: 33017585 DOI: 10.1016/j.ygcen.2020.113640] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 09/14/2020] [Accepted: 09/28/2020] [Indexed: 01/15/2023]
Abstract
A common response to parasite infestations is increased production of glucocorticoid hormones that regulate immune function. We examined relationships between ectoparasite infestations and fecal corticosterone metabolites (FCM) in deer mice (Peromyscus maniculatus). Furthermore, we experimentally removed fleas to determine if reductions in ectoparasites affected FCM production. Individuals were assigned to control (no flea removal) or treatment (anti-flea application, physical combing) groups and individuals were recaptured to assess changes in FCM concentrations. There was a significant and negative effect of number of anti-flea treatment applications on FCM concentrations of deer mice. However, models including host biology traits and environmental predictors had a better model fit compared to models containing ectoparasite predictors. In particular, there was a significant relationship of deer mouse FCM with date and host age, where glucocorticoid production decreased towards the end of the breeding season and increased with age. Overall, adverse events associated with reproduction and age class, rather than ectoparasites, may be more important to variation in glucocorticoids of deer mice.
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Affiliation(s)
- Jasmine S M Veitch
- Department of Biology, Laurentian University, 935 Ramsey Lake Road, Sudbury, ON P3E 2C6, Canada. https://www.0000-0003-0010-3475
| | - Jeff Bowman
- Ontario Ministry of Natural Resources and Forestry, Wildlife Research and Monitoring Section, 2140 East Bank Drive, DNA Building, Peterborough, ON K9L 0G2, Canada; Trent University, 1600 East Bank Drive, Peterborough, ON K9L 0G2, Canada
| | - Gabriela Mastromonaco
- Reproductive Sciences, Toronto Zoo, 361A Old Finch Avenue, Toronto, ON M1B 5K7, Canada
| | - Albrecht I Schulte-Hostedde
- Department of Biology, Laurentian University, 935 Ramsey Lake Road, Sudbury, ON P3E 2C6, Canada. https://www.0000-0001-7263-4764
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Mayer M, Aparicio Estalella C, Windels SK, Rosell FN. Landscape structure and population density affect intraspecific aggression in beavers. Ecol Evol 2020; 10:13883-13894. [PMID: 33391688 PMCID: PMC7771123 DOI: 10.1002/ece3.6980] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 09/21/2020] [Accepted: 10/13/2020] [Indexed: 12/16/2022] Open
Abstract
Intraspecific competition plays an important role for territory acquisition and occupancy, in turn affecting individual fitness. Thus, understanding the drivers of intraspecific aggression can increase our understanding of population dynamics. Here, we investigated intraspecific aggression in Eurasian (Castor fiber) and North American (Castor canadensis) beavers that are both monogamous, territorial mammals. Combined, we examined tail scars from >1,000 beavers (>2,000 capture events) as part of two long-term studies in Norway and the USA. We investigated the influence of landscape structure, population density, sex, age, and (for Eurasian beavers only) social status and group size on the number of tail scars caused by conspecifics. The number of tail scars was affected by population density in well-connected landscape types (large lakes and rivers), but not in more isolated areas (ponds), where individuals generally had fewer tail scars. Further, the relationship of population density was not linear. In the North American beaver population occurring in large lakes, intraspecific aggression increased with population density. Conversely, in the saturated Eurasian beaver population, intraspecific aggression was in a negative relationship with population density (except at the highest densities), likely due to inverse density-dependent intruder pressure via dispersers. Our findings emphasize that population density can affect intraspecific aggression depending on landscape structure, which might have important consequences for local patterns of dispersal, mate change, and territory occupancy, all of which can affect population dynamics.
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Affiliation(s)
- Martin Mayer
- Faculty of Technology, Natural Sciences, and Maritime SciencesDepartment of Natural Sciences and Environmental HealthUniversity of South‐Eastern NorwayBø i Vestfold and TelemarkNorway
- Department of BioscienceAarhus UniversityAarhusDenmark
| | - Clàudia Aparicio Estalella
- Faculty of Technology, Natural Sciences, and Maritime SciencesDepartment of Natural Sciences and Environmental HealthUniversity of South‐Eastern NorwayBø i Vestfold and TelemarkNorway
- Faculty of BiologyUniversity of BarcelonaBarcelonaSpain
| | | | - Frank N. Rosell
- Faculty of Technology, Natural Sciences, and Maritime SciencesDepartment of Natural Sciences and Environmental HealthUniversity of South‐Eastern NorwayBø i Vestfold and TelemarkNorway
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Gable TD, Johnson-Bice SM, Homkes AT, Windels SK, Bump JK. Outsized effect of predation: Wolves alter wetland creation and recolonization by killing ecosystem engineers. SCIENCE ADVANCES 2020; 6:6/46/eabc5439. [PMID: 33188026 PMCID: PMC7673763 DOI: 10.1126/sciadv.abc5439] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Accepted: 09/30/2020] [Indexed: 05/04/2023]
Abstract
Gray wolves are a premier example of how predators can transform ecosystems through trophic cascades. However, whether wolves change ecosystems as drastically as previously suggested has been increasingly questioned. We demonstrate how wolves alter wetland creation and recolonization by killing dispersing beavers. Beavers are ecosystem engineers that generate most wetland creation throughout boreal ecosystems. By studying beaver pond creation and recolonization patterns coupled with wolf predation on beavers, we determined that 84% of newly created and recolonized beaver ponds remained occupied until the fall, whereas 0% of newly created and recolonized ponds remained active after a wolf killed the dispersing beaver that colonized that pond. By affecting where and when beavers engineer ecosystems, wolves alter all of the ecological processes (e.g., water storage, nutrient cycling, and forest succession) that occur due to beaver-created impoundments. Our study demonstrates how predators have an outsized effect on ecosystems when they kill ecosystem engineers.
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Affiliation(s)
- Thomas D Gable
- Department of Fisheries, Wildlife, and Conservation Biology, University of Minnesota, 2003 Upper Buford Circle, St. Paul, MN 55801, USA.
| | - Sean M Johnson-Bice
- Department of Biological Sciences, University of Manitoba, 50 Sifton Road, Winnipeg, Manitoba R3T 2N2, Canada
| | - Austin T Homkes
- Department of Fisheries, Wildlife, and Conservation Biology, University of Minnesota, 2003 Upper Buford Circle, St. Paul, MN 55801, USA
| | - Steve K Windels
- Department of Fisheries, Wildlife, and Conservation Biology, University of Minnesota, 2003 Upper Buford Circle, St. Paul, MN 55801, USA
- Voyageurs National Park, 360 Highway 11 E, International Falls, MN 56649, USA
| | - Joseph K Bump
- Department of Fisheries, Wildlife, and Conservation Biology, University of Minnesota, 2003 Upper Buford Circle, St. Paul, MN 55801, USA
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Long-term capture and handling effects on body condition, reproduction and survival in a semi-aquatic mammal. Sci Rep 2020; 10:17886. [PMID: 33087816 PMCID: PMC7578049 DOI: 10.1038/s41598-020-74933-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 10/08/2020] [Indexed: 11/11/2022] Open
Abstract
In long-term individual-based field studies, several parameters need to be assessed repeatedly to fully understand the potential fitness effects on individuals. Often studies only evaluate capture stress that appears in the immediate weeks or breeding season and even long-term studies fail to evaluate the long-term effects of their capture procedures. We investigated effects of long-term repeated capture and handling of individuals in a large semi-aquatic rodent using more than 20 years of monitoring data from a beaver population in Norway. To investigate the effects, we corrected for ecological factors and analysed the importance of total capture and handling events, years of monitoring and deployment of telemetry devices on measures related to body condition, reproduction and survival of individual beavers. Body mass of dominant individuals decreased considerably with number of capture events (107 g per capture), but we found no statistically clear short or long-term effects of capture and handling on survival or other body condition indices. Annual litter size decreased with increasing number of captures among older individuals. Number of captures furthermore negatively affected reproduction in the beginning of the monitoring, but the effect decreased over the years, indicating habituation to repeated capture and handling. By assessing potential impacts on several fitness-related parameters at multiple times, we can secure the welfare of wild animal populations when planning and executing future conservation studies as well as ensure ecologically reliable research data.
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McClanahan K, Rosell F, Mayer M. Minding your own business: low pair cohesion in a territorial, monogamous mammal. Anim Behav 2020. [DOI: 10.1016/j.anbehav.2020.05.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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14
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Bartra Cabré L, Mayer M, Steyaert S, Rosell F. Beaver (Castor fiber) activity and spatial movement in response to light and weather conditions. Mamm Biol 2020. [DOI: 10.1007/s42991-020-00029-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
AbstractAnimal behaviour can affect individual fitness and is influenced by exogenous and endogenous factors. Here, we investigated how light (daylight length and moonlight), weather (precipitation and temperature), age, sex and social status affected activity and movement of a semiaquatic mammal, the Eurasian beaver (Castor fiber), using GPS relocation data from 47 individuals in south-eastern Norway. Independent of daylight length, beavers had a mean daily activity time of 9:42 h and reduced their activity periods when they were older, most likely due to senescence. In line with this, older individuals also spent less time in water and moved shorter distances. Furthermore, beavers reduced their activity periods in drier weather conditions and spent less time on land during brighter nights and drier conditions, indicating a predation risk avoidance strategy. Individuals spent less time in the water during the colder parts of the year and moved shorter distances with decreasing temperature, suggesting thermal constraints. Our study adds to the increasing amount of evidence that animal behaviour is modulated by various endogenous and exogenous factors, and that weather conditions can affect their behaviour. It remains to be tested, however, how climate variability together with hunting and predation pressure affect space use and demography in species such as the Eurasian beaver.
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