Woodland caribou (Rangifer tarandus caribou) are designated as Threatened or Endangered in Canada, with many populations being at risk of extirpation. Approaches for caribou conservation can be both invasive and expensive. For example, maternity penning involves the relocation of pregnant females to a predator‐free fenced enclosure where they are held for 20–22 weeks. This activity greatly reduces the risk of predation for adult females and their dependent calves, but requires the construction, maintenance, and monitoring of a penning facility as well as the risk associated with the capture and transport of adult caribou. With only four maternity pen trials within the last decade, there has been little study of the potential influence of maternity penning on the distribution and habitat use of caribou after release. We used Brownian Bridge Movement Models to examine changes in range fidelity and overall range use of the Klinse‐Za caribou herd in north‐central British Columbia, Canada, following eight years of maternity penning. We generated annual home range utilisation distributions and examined the space use of caribou among years and between penned and unpenned animals, as well as pre‐penning and post‐penning time periods. We found that following penning, caribou shifted distribution to areas near maternity pens and expanded their overall use of range. However, caribou did not shift their distribution relative to the elevation of their mountainous habitats. Our results suggest that caribou can adapt to capture and forced displacement without altering patterns of instinctual or learned habitat use.
{"title":"Go where you know: range expansion and fidelity in mountain caribou following eight years of maternity penning","authors":"D. Hoffart, C. J. Johnson, R. S. McNay","doi":"10.1111/acv.12975","DOIUrl":"https://doi.org/10.1111/acv.12975","url":null,"abstract":"Woodland caribou (<jats:italic>Rangifer tarandus caribou</jats:italic>) are designated as Threatened or Endangered in Canada, with many populations being at risk of extirpation. Approaches for caribou conservation can be both invasive and expensive. For example, maternity penning involves the relocation of pregnant females to a predator‐free fenced enclosure where they are held for 20–22 weeks. This activity greatly reduces the risk of predation for adult females and their dependent calves, but requires the construction, maintenance, and monitoring of a penning facility as well as the risk associated with the capture and transport of adult caribou. With only four maternity pen trials within the last decade, there has been little study of the potential influence of maternity penning on the distribution and habitat use of caribou after release. We used Brownian Bridge Movement Models to examine changes in range fidelity and overall range use of the Klinse‐Za caribou herd in north‐central British Columbia, Canada, following eight years of maternity penning. We generated annual home range utilisation distributions and examined the space use of caribou among years and between penned and unpenned animals, as well as pre‐penning and post‐penning time periods. We found that following penning, caribou shifted distribution to areas near maternity pens and expanded their overall use of range. However, caribou did not shift their distribution relative to the elevation of their mountainous habitats. Our results suggest that caribou can adapt to capture and forced displacement without altering patterns of instinctual or learned habitat use.","PeriodicalId":50786,"journal":{"name":"Animal Conservation","volume":"87 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142260625","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. D. G. Ranjeewa, R. J. Thomas, D. K. Weerakoon, G. H. N. A. Sandanayake, P. Fernando
Electric fences are widely used in human–elephant conflict mitigation. However, elephants constantly challenge and overcome fences, which is a growing concern. We studied how elephants crossed the perimeter electric fence around the Udawalawe National Park (UWNP), Sri Lanka. Using camera traps, we monitored 18 fence posts and an open gate in the fence over 605 days from 2016 to 2019. Photographs of 3097 fence crossings were analysed to obtain demographic data for fence crossing elephants, crossing methods, and the daily and seasonal timing of fence crossing. We identified 77 adult males and 12 adult females that crossed the fence, which represent about 17% of the adult elephants in UWNP. Most of the crossings were through the open gate at night. Elephants used a variety of crossing methods, comprised of crossing at the open gate, at previously toppled posts, by crashing through wires and stepping over wires, as well as by using the trunk or forefeet to topple posts. Fence voltage was not a determinant of fence crossing. The frequency and timing of fence crossings varied between locations with later exits and less time spent outside, at crossing points bordering human dominated areas. Our results emphasis on the importance of taking into account the problem solving abilities of elephants in fence design and location, such as energising fence posts and constructing exclosure fences at the boundaries of crop fields and settlements, in employing electric fences to mitigate human‐elephant conflict.
{"title":"How did the elephant cross the fence? Electric fence crossing by elephants in Udawalawe, Sri Lanka","authors":"A. D. G. Ranjeewa, R. J. Thomas, D. K. Weerakoon, G. H. N. A. Sandanayake, P. Fernando","doi":"10.1111/acv.12982","DOIUrl":"https://doi.org/10.1111/acv.12982","url":null,"abstract":"Electric fences are widely used in human–elephant conflict mitigation. However, elephants constantly challenge and overcome fences, which is a growing concern. We studied how elephants crossed the perimeter electric fence around the Udawalawe National Park (UWNP), Sri Lanka. Using camera traps, we monitored 18 fence posts and an open gate in the fence over 605 days from 2016 to 2019. Photographs of 3097 fence crossings were analysed to obtain demographic data for fence crossing elephants, crossing methods, and the daily and seasonal timing of fence crossing. We identified 77 adult males and 12 adult females that crossed the fence, which represent about 17% of the adult elephants in UWNP. Most of the crossings were through the open gate at night. Elephants used a variety of crossing methods, comprised of crossing at the open gate, at previously toppled posts, by crashing through wires and stepping over wires, as well as by using the trunk or forefeet to topple posts. Fence voltage was not a determinant of fence crossing. The frequency and timing of fence crossings varied between locations with later exits and less time spent outside, at crossing points bordering human dominated areas. Our results emphasis on the importance of taking into account the problem solving abilities of elephants in fence design and location, such as energising fence posts and constructing exclosure fences at the boundaries of crop fields and settlements, in employing electric fences to mitigate human‐elephant conflict.","PeriodicalId":50786,"journal":{"name":"Animal Conservation","volume":"1 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142180649","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Northern bobwhites (Colinus virginianus) have become a species of great conservation priority because of widespread and ongoing population declines. Long‐distance translocations are becoming increasingly used to access a source population with densities high enough to support translocation. Two key uncertainties exist regarding the efficacy of long‐distance translocations: choosing a source population with adaptations that will be successful in a novel environment and mitigating the stress response common during the translocation process. We translocated bobwhites from the South Texas Plains and the Floridian Coastal Plain to a recipient site in the Floridian Coastal Plain in 2021 and 2022 to compare the survival and productivity of bobwhites translocated from two different source populations. We also evaluated how varying holding times during the translocation process influenced the success of the translocated individuals. Breeding season survival, nest propensity and fecundity were greater for Florida resident and Florida translocated bobwhites relative to Texas translocated bobwhites. We observed high rates of mortality during the transport and holding processes, but holding time did not affect breeding season survival of Texas translocated bobwhites. Both nest success and fecundity of Texas translocated bobwhites were negatively affected by holding time. Bobwhites translocated long distances may have the adaptive capacity to be successful in novel environments, but the consequences of translocation stress can be detrimental. Future translocation planning should consider choosing source populations from similar ecoregions to simultaneously decrease translocation distances and potential stress from translocation.
{"title":"Source population and time spent in captivity affect survival and reproduction of long‐distance translocated northern bobwhites","authors":"A. Schmidt, G. Beane, J. A. Martin","doi":"10.1111/acv.12985","DOIUrl":"https://doi.org/10.1111/acv.12985","url":null,"abstract":"Northern bobwhites (<jats:italic>Colinus virginianus</jats:italic>) have become a species of great conservation priority because of widespread and ongoing population declines. Long‐distance translocations are becoming increasingly used to access a source population with densities high enough to support translocation. Two key uncertainties exist regarding the efficacy of long‐distance translocations: choosing a source population with adaptations that will be successful in a novel environment and mitigating the stress response common during the translocation process. We translocated bobwhites from the South Texas Plains and the Floridian Coastal Plain to a recipient site in the Floridian Coastal Plain in 2021 and 2022 to compare the survival and productivity of bobwhites translocated from two different source populations. We also evaluated how varying holding times during the translocation process influenced the success of the translocated individuals. Breeding season survival, nest propensity and fecundity were greater for Florida resident and Florida translocated bobwhites relative to Texas translocated bobwhites. We observed high rates of mortality during the transport and holding processes, but holding time did not affect breeding season survival of Texas translocated bobwhites. Both nest success and fecundity of Texas translocated bobwhites were negatively affected by holding time. Bobwhites translocated long distances may have the adaptive capacity to be successful in novel environments, but the consequences of translocation stress can be detrimental. Future translocation planning should consider choosing source populations from similar ecoregions to simultaneously decrease translocation distances and potential stress from translocation.","PeriodicalId":50786,"journal":{"name":"Animal Conservation","volume":"7 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142180651","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
<p>The disruption in socio-economic activity during the COVID-19 pandemic, commonly labeled the “anthropause,” provided an opportunity to observe the effects of a pause in human-related activities on ecological systems (e.g., Naidoo & Burton, <span>2020</span>; Gaiser <i>et al</i>., <span>2022</span>; Perkins, Shilling, & Collinson, <span>2022</span>). However, this treatment of reduced activity was not under the spatial or temporal control of researchers, and therefore, estimated effects could be confounded in time by unobserved factors that varied over the course of the study.</p><p>In British Columbia, Canada, heli-ski operators suspended or severely curtailed their activities for the 2020–2021 season in response to international border closures and public health requirements (HeliCat Canada, <span>2022</span>). Gill <i>et al</i>. (<span>2023</span>) analyzed the late winter movements of woodland caribou (<i>Rangifer tarandus caribou</i>) before, during, and after the anthropause. They reported that caribou home ranges were largest during the anthropause, and inferred that the reduction in heli-skiing activity released caribou from a “landscape of fear” (Bleicher, <span>2017</span>). However, Gill <i>et al</i>.'s (2023) analysis identified a year effect, but not evidence that heli-skiing was the cause.</p><p>Mean home range size during the late winter anthropause year of 2020–21 was indeed larger than in years before or after. But Gill <i>et al</i>. (<span>2023</span>) found that home range overlap with heli-ski tenures was not a significant covariate, meaning that ranges were larger during the anthropause regardless of their pre- or post-anthropause exposure to heli-ski activity. With nearly a third of home ranges occurring entirely outside tenures, their data are well-suited for re-analysis as a Before-After-Control-Impact design, with ranges located outside tenures serving as a quasi-control group (untreated but not randomly assigned). I conducted this analysis (Appendix S1) and found a larger increase in home range size during the anthropause among “control” caribou than among “impact” caribou that had home ranges that overlapped tenures (<i>P =</i> 0.01, <i>β</i> = −1.03). Post-anthropause, the resumption of heli-skiing was associated with a reduction in home range size that did not differ among “control” and “impact” caribou (<i>P =</i> 0.28, <i>β</i> = −0.31; Fig. 1). Thus, changes in home range size from before, during the anthropause treatment, and after, did not provide evidence of a heli-ski effect.</p><p>As Gill <i>et al</i>. (<span>2023</span>) noted, tenure overlap is only a coarse measure of exposure to heli-skiing because the distribution of flights and skiing is not uniform in space or time within tenures. But outside tenures, caribou would not have been subject to landings, take-offs, or skiing during years of normal operation, but some might have experienced some helicopter overflights. Detailed flight and skiing dat
{"title":"That woodland Caribou were released during the anthropause from a ‘landscape of fear’ caused by heli-skiing is not supported by available evidence","authors":"Steven F. Wilson","doi":"10.1111/acv.12967","DOIUrl":"https://doi.org/10.1111/acv.12967","url":null,"abstract":"<p>The disruption in socio-economic activity during the COVID-19 pandemic, commonly labeled the “anthropause,” provided an opportunity to observe the effects of a pause in human-related activities on ecological systems (e.g., Naidoo & Burton, <span>2020</span>; Gaiser <i>et al</i>., <span>2022</span>; Perkins, Shilling, & Collinson, <span>2022</span>). However, this treatment of reduced activity was not under the spatial or temporal control of researchers, and therefore, estimated effects could be confounded in time by unobserved factors that varied over the course of the study.</p><p>In British Columbia, Canada, heli-ski operators suspended or severely curtailed their activities for the 2020–2021 season in response to international border closures and public health requirements (HeliCat Canada, <span>2022</span>). Gill <i>et al</i>. (<span>2023</span>) analyzed the late winter movements of woodland caribou (<i>Rangifer tarandus caribou</i>) before, during, and after the anthropause. They reported that caribou home ranges were largest during the anthropause, and inferred that the reduction in heli-skiing activity released caribou from a “landscape of fear” (Bleicher, <span>2017</span>). However, Gill <i>et al</i>.'s (2023) analysis identified a year effect, but not evidence that heli-skiing was the cause.</p><p>Mean home range size during the late winter anthropause year of 2020–21 was indeed larger than in years before or after. But Gill <i>et al</i>. (<span>2023</span>) found that home range overlap with heli-ski tenures was not a significant covariate, meaning that ranges were larger during the anthropause regardless of their pre- or post-anthropause exposure to heli-ski activity. With nearly a third of home ranges occurring entirely outside tenures, their data are well-suited for re-analysis as a Before-After-Control-Impact design, with ranges located outside tenures serving as a quasi-control group (untreated but not randomly assigned). I conducted this analysis (Appendix S1) and found a larger increase in home range size during the anthropause among “control” caribou than among “impact” caribou that had home ranges that overlapped tenures (<i>P =</i> 0.01, <i>β</i> = −1.03). Post-anthropause, the resumption of heli-skiing was associated with a reduction in home range size that did not differ among “control” and “impact” caribou (<i>P =</i> 0.28, <i>β</i> = −0.31; Fig. 1). Thus, changes in home range size from before, during the anthropause treatment, and after, did not provide evidence of a heli-ski effect.</p><p>As Gill <i>et al</i>. (<span>2023</span>) noted, tenure overlap is only a coarse measure of exposure to heli-skiing because the distribution of flights and skiing is not uniform in space or time within tenures. But outside tenures, caribou would not have been subject to landings, take-offs, or skiing during years of normal operation, but some might have experienced some helicopter overflights. Detailed flight and skiing dat","PeriodicalId":50786,"journal":{"name":"Animal Conservation","volume":"27 4","pages":"409-411"},"PeriodicalIF":2.8,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/acv.12967","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142123360","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
R. Gill, R. Serrouya, A. M. Calvert, A. Ford, R. Steenweg, M. J. Noonan
{"title":"Movement ecology of endangered caribou during a COVID-19 mediated pause in winter recreation – response to Wilson (2024)","authors":"R. Gill, R. Serrouya, A. M. Calvert, A. Ford, R. Steenweg, M. J. Noonan","doi":"10.1111/acv.12981","DOIUrl":"https://doi.org/10.1111/acv.12981","url":null,"abstract":"","PeriodicalId":50786,"journal":{"name":"Animal Conservation","volume":"27 4","pages":"412-414"},"PeriodicalIF":2.8,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142123361","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
K. J. Macdonald, T. S. Doherty, B. A. Hradsky, D. A. Driscoll
Fire, invasive predators and low rainfall are key disturbances that interact to negatively impact wildlife. Reptiles are a highly threatened group, yet they have rarely been the focus of threat interaction research. Research assessing the impacts of disturbance on wildlife have typically focussed on changes in species richness and abundance. However, these metrics largely overlook the non‐lethal effects on individuals and populations persisting within disturbed landscapes. Body condition is an individual‐level response metric that is easily obtainable and provides insight into the cumulative behavioural and morphological changes within a population. We used a landscape‐scale natural experiment in southern Australia to investigate the impacts of prescribed fire severity, invasive red fox (Vulpes vulpes) control, low rainfall conditions and their interactive effects on reptile body condition. Low rainfall had pervasive negative effects on body condition, while prescribed fire had negative effects on the larger, viviparous species. We found a three‐way interactive effect, whereby the negative effects of fire and low rainfall were greater in areas where red foxes were controlled. These results indicate that there are complex ecological interactions at play, potentially including intra‐specific competition and interspecific interactions. Lower body condition in disturbed environments could have lasting implications for individual fitness and population persistence. For instance, species with lower body condition one‐year post‐fire could be more vulnerable to another fire event, compared to species that are able to maintain condition in post‐fire landscapes. With reptile body condition lower in a drier year, we advise minimising additional disturbance (e.g. avoid prescribed fires) during low rainfall years and drought periods. Along with research into ecological interactions, understanding how body condition indices relate to altered fitness is a priority knowledge gap. Such research could improve the ability to predict how species and populations will respond to future disturbances, a key challenge in wildlife disturbance research.
{"title":"Disturbance and ecosystem management interact to shape reptile body condition","authors":"K. J. Macdonald, T. S. Doherty, B. A. Hradsky, D. A. Driscoll","doi":"10.1111/acv.12983","DOIUrl":"https://doi.org/10.1111/acv.12983","url":null,"abstract":"Fire, invasive predators and low rainfall are key disturbances that interact to negatively impact wildlife. Reptiles are a highly threatened group, yet they have rarely been the focus of threat interaction research. Research assessing the impacts of disturbance on wildlife have typically focussed on changes in species richness and abundance. However, these metrics largely overlook the non‐lethal effects on individuals and populations persisting within disturbed landscapes. Body condition is an individual‐level response metric that is easily obtainable and provides insight into the cumulative behavioural and morphological changes within a population. We used a landscape‐scale natural experiment in southern Australia to investigate the impacts of prescribed fire severity, invasive red fox (<jats:italic>Vulpes vulpes</jats:italic>) control, low rainfall conditions and their interactive effects on reptile body condition. Low rainfall had pervasive negative effects on body condition, while prescribed fire had negative effects on the larger, viviparous species. We found a three‐way interactive effect, whereby the negative effects of fire and low rainfall were greater in areas where red foxes were controlled. These results indicate that there are complex ecological interactions at play, potentially including intra‐specific competition and interspecific interactions. Lower body condition in disturbed environments could have lasting implications for individual fitness and population persistence. For instance, species with lower body condition one‐year post‐fire could be more vulnerable to another fire event, compared to species that are able to maintain condition in post‐fire landscapes. With reptile body condition lower in a drier year, we advise minimising additional disturbance (e.g. avoid prescribed fires) during low rainfall years and drought periods. Along with research into ecological interactions, understanding how body condition indices relate to altered fitness is a priority knowledge gap. Such research could improve the ability to predict how species and populations will respond to future disturbances, a key challenge in wildlife disturbance research.","PeriodicalId":50786,"journal":{"name":"Animal Conservation","volume":"54 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142180652","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
T. Curk, J. Melzheimer, O. Aschenborn, A. Amar, H. Kolberg, R. Garbett, G. Maude, R. P. Reading, M. Selebatso, F. Berzaghi, G. P. Hempson, A. Botha, R. L. Thomson, G. Tate, O. Spiegel, A. Santangeli
Given the current biodiversity crisis, understanding how animals move across a landscape dotted with different anthropogenic threats and the consequences of those threats for animals is paramount to devising evidence-based conservation interventions. Vultures roam across large areas and are highly exposed to poisoning, which represents a particularly damaging form of wildlife crime. In this study, we introduce a framework for quantifying the exposure to threats and illustrate an example of poisoning risk as a threat in an endangered African vulture species, the Lappet-faced Vulture (Torgos tracheliotos). We combined GPS tracking data of 19 individuals collected between 2012 and 2022 with food availability and spatial threat maps of both intentional (poachers directly targeting vultures) and unintentional (farmers aiming to kill carnivores, with vultures being secondarily affected) poisoning across most of Southern Africa. We identified poisoning hotspots in northern Botswana and south-eastern Namibia. These areas were also associated with a high number of vulture mortalities, providing additional support for poisoning risk. Northern Botswana and areas at the border between Botswana and South Africa were characterized by high food availability, potentially amplifying the mortality rate by attracting vultures from surrounding areas. Our results offer valuable insights for regional vulture conservation, together with a methodological framework for quantifying and mapping the spatial exposure to threats for mobile species of conservation concern, enabling improved targeting of conservation actions.
{"title":"Integrating threat mapping and animal movement data to identify high-risk areas for endangered mobile species","authors":"T. Curk, J. Melzheimer, O. Aschenborn, A. Amar, H. Kolberg, R. Garbett, G. Maude, R. P. Reading, M. Selebatso, F. Berzaghi, G. P. Hempson, A. Botha, R. L. Thomson, G. Tate, O. Spiegel, A. Santangeli","doi":"10.1111/acv.12980","DOIUrl":"https://doi.org/10.1111/acv.12980","url":null,"abstract":"Given the current biodiversity crisis, understanding how animals move across a landscape dotted with different anthropogenic threats and the consequences of those threats for animals is paramount to devising evidence-based conservation interventions. Vultures roam across large areas and are highly exposed to poisoning, which represents a particularly damaging form of wildlife crime. In this study, we introduce a framework for quantifying the exposure to threats and illustrate an example of poisoning risk as a threat in an endangered African vulture species, the Lappet-faced Vulture (<i>Torgos tracheliotos</i>). We combined GPS tracking data of 19 individuals collected between 2012 and 2022 with food availability and spatial threat maps of both intentional (poachers directly targeting vultures) and unintentional (farmers aiming to kill carnivores, with vultures being secondarily affected) poisoning across most of Southern Africa. We identified poisoning hotspots in northern Botswana and south-eastern Namibia. These areas were also associated with a high number of vulture mortalities, providing additional support for poisoning risk. Northern Botswana and areas at the border between Botswana and South Africa were characterized by high food availability, potentially amplifying the mortality rate by attracting vultures from surrounding areas. Our results offer valuable insights for regional vulture conservation, together with a methodological framework for quantifying and mapping the spatial exposure to threats for mobile species of conservation concern, enabling improved targeting of conservation actions.","PeriodicalId":50786,"journal":{"name":"Animal Conservation","volume":"34 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142180654","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
L. E. Silvetti, G. Gavier Pizarro, J. R. Arcamone, L. M. Bellis
Land‐use change is one of the main threats to biodiversity at the global level, and subtropical dry forests are not exempt from such a threat. Recent studies suggest that species can become extinct with a considerable time lag, even if no further habitat loss occurs. Hence, there may be an extinction debt, which poses a great challenge to conservation. Here, we analyzed the response of taxonomic and functional richness of forest and understory specialist birds to 30 years (data from 1989, 2004 and 2019) of land‐cover and land‐use changes in the Chaco Serrano forest of central Argentina. Our results showed the occurrence of extinction debt in both forest and understory specialist birds, with such debt being greater in forest specialist birds. Results for species trait debt were inconclusive. We also found evidence that birds are not equally sensitive to land‐use change, indicating a species‐specific response. We conclude that the current presence of some large native forest patches and an intermediate degree of isolation in the region might be prolonging the persistence of some bird species and traits. Moreover, ecological legacies can strongly affect the current species distribution pattern and the permanence of functional traits in fragmented landscapes. These findings should be considered in conservation planning.
{"title":"Delayed responses and extinction debt: an opportunity for the conservation of Chaco Serrano forest birds","authors":"L. E. Silvetti, G. Gavier Pizarro, J. R. Arcamone, L. M. Bellis","doi":"10.1111/acv.12979","DOIUrl":"https://doi.org/10.1111/acv.12979","url":null,"abstract":"Land‐use change is one of the main threats to biodiversity at the global level, and subtropical dry forests are not exempt from such a threat. Recent studies suggest that species can become extinct with a considerable time lag, even if no further habitat loss occurs. Hence, there may be an extinction debt, which poses a great challenge to conservation. Here, we analyzed the response of taxonomic and functional richness of forest and understory specialist birds to 30 years (data from 1989, 2004 and 2019) of land‐cover and land‐use changes in the Chaco Serrano forest of central Argentina. Our results showed the occurrence of extinction debt in both forest and understory specialist birds, with such debt being greater in forest specialist birds. Results for species trait debt were inconclusive. We also found evidence that birds are not equally sensitive to land‐use change, indicating a species‐specific response. We conclude that the current presence of some large native forest patches and an intermediate degree of isolation in the region might be prolonging the persistence of some bird species and traits. Moreover, ecological legacies can strongly affect the current species distribution pattern and the permanence of functional traits in fragmented landscapes. These findings should be considered in conservation planning.","PeriodicalId":50786,"journal":{"name":"Animal Conservation","volume":"29 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142180653","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
K. J. Loope, J. N. DeSha, M. J. Aresco, K. T. Shoemaker, E. A. Hunter
Human‐mediated animal movement can expose wildlife populations to novel environments. Phenotypic plasticity can buffer against the challenges presented by novel environments, while adaptation to local ecosystems may limit resilience in novel ecosystems. Outbreeding depression during the mixing of disparate gene pools can also reduce reproductive success after long‐distance movement. Here, we use a ‘common‐garden’ population of gopher tortoises (Gopherus polyphemus), translocated from numerous sites across the state of Florida, USA, to a mitigation site in the north‐west (panhandle) region to assess whether geographic origin, outbreeding effects, and behavioral plasticity influence reproductive success in this threatened keystone species. We found that females from north‐east Florida produced clutches with lower hatching success than females from other regions. We detected regional differentiation in nest site selection behavior in the common environment of the translocation site, though these differences did not mediate the regional effect on hatching success. We also found evidence for outbreeding depression: hatching success declined with increasing parental geographic and genetic distances, dropping from 93% to 67% across the range of observed parental genetic distances. Together, these results suggest that newly admixed populations may suffer reproductive costs due to historical population differentiation, and that undetected outbreeding depression could significantly hamper conservation efforts for this species and others undergoing a variety of human‐mediated movements.
{"title":"Common‐garden experiment reveals outbreeding depression and region‐of‐origin effects on reproductive success in a frequently translocated tortoise","authors":"K. J. Loope, J. N. DeSha, M. J. Aresco, K. T. Shoemaker, E. A. Hunter","doi":"10.1111/acv.12977","DOIUrl":"https://doi.org/10.1111/acv.12977","url":null,"abstract":"Human‐mediated animal movement can expose wildlife populations to novel environments. Phenotypic plasticity can buffer against the challenges presented by novel environments, while adaptation to local ecosystems may limit resilience in novel ecosystems. Outbreeding depression during the mixing of disparate gene pools can also reduce reproductive success after long‐distance movement. Here, we use a ‘common‐garden’ population of gopher tortoises (<jats:italic>Gopherus polyphemus</jats:italic>), translocated from numerous sites across the state of Florida, USA, to a mitigation site in the north‐west (panhandle) region to assess whether geographic origin, outbreeding effects, and behavioral plasticity influence reproductive success in this threatened keystone species. We found that females from north‐east Florida produced clutches with lower hatching success than females from other regions. We detected regional differentiation in nest site selection behavior in the common environment of the translocation site, though these differences did not mediate the regional effect on hatching success. We also found evidence for outbreeding depression: hatching success declined with increasing parental geographic and genetic distances, dropping from 93% to 67% across the range of observed parental genetic distances. Together, these results suggest that newly admixed populations may suffer reproductive costs due to historical population differentiation, and that undetected outbreeding depression could significantly hamper conservation efforts for this species and others undergoing a variety of human‐mediated movements.","PeriodicalId":50786,"journal":{"name":"Animal Conservation","volume":"8 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142180682","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
F. Vivier, C. Andrés, J. Gonzalvo, K. Fertitta, M. van Aswegen, V. Foroughirad, J. Mann, M. McEntee, R. S. Wells, L. Bejder
Assessing trends in population abundance and demographics is crucial for managing long‐lived and slow‐reproducing species. Obtaining demographic data, and age‐structure information, is challenging, notably for cetaceans. To address this, we combined Unoccupied Aerial System (UAS; drone) photogrammetry data with long‐term (>20 years) photo identification data to assess the age‐structure of the critically endangered sub‐population of common bottlenose dolphins (Tursiops truncatus) of the Gulf of Ambracia, Greece. We compared our findings with two extensively studied non‐endangered bottlenose dolphin populations (T. aduncus in Shark Bay, Australia, and T. truncatus in Sarasota Bay, USA). Using a log‐linear model, we estimated the total body lengths (TL) of 160 known‐aged dolphins between 2021 and 2023 from blowhole‐to‐dorsal‐fin distance (BHDF) measurements collected during surfacing. Subsequently, we tested four growth models to establish an age‐length growth curve. We assessed the sub‐population's age‐structure using three methods: (1) UAS‐derived TL estimates, (2) age‐length growth curve and (3) long‐term monitoring data (i.e. actual age‐structure). UAS‐measured TL (247.6 ± 32.2 cm) and UAS‐estimated TL (246.0 ± 34.7 cm) of the Greek sub‐population showed no differences. The Richards Growth model suggested an asymptotic length of 258.5 cm. In Greece, resulting age‐structure estimates across the three methods revealed no significant differences (P > 0.1). The Gulf of Ambracia and Shark Bay populations shared similar age‐structures, while Sarasota had higher proportions of 2–10 year‐olds and lower proportions of 10+ year‐olds. All populations had a comparable proportion of 0–2 year‐olds (~14%), indicating a similar reproductive rate. Our findings suggest stability in the Greek sub‐population; however, additional monitoring of reproductive parameters is essential before concluding its status. We demonstrated the effectiveness of UAS‐photogrammetry in rapidly quantifying population age‐structure, including scenarios with limited or no demographic data. This technique shows promise for enhancing precision, timeliness, cost‐effectiveness and efficiency in population monitoring and informing timely conservation management decisions.
{"title":"Inferring dolphin population status: using unoccupied aerial systems to quantify age‐structure","authors":"F. Vivier, C. Andrés, J. Gonzalvo, K. Fertitta, M. van Aswegen, V. Foroughirad, J. Mann, M. McEntee, R. S. Wells, L. Bejder","doi":"10.1111/acv.12978","DOIUrl":"https://doi.org/10.1111/acv.12978","url":null,"abstract":"Assessing trends in population abundance and demographics is crucial for managing long‐lived and slow‐reproducing species. Obtaining demographic data, and age‐structure information, is challenging, notably for cetaceans. To address this, we combined Unoccupied Aerial System (UAS; drone) photogrammetry data with long‐term (>20 years) photo identification data to assess the age‐structure of the critically endangered sub‐population of common bottlenose dolphins (<jats:italic>Tursiops truncatus</jats:italic>) of the Gulf of Ambracia, Greece. We compared our findings with two extensively studied non‐endangered bottlenose dolphin populations (<jats:italic>T. aduncus</jats:italic> in Shark Bay, Australia, and <jats:italic>T. truncatus</jats:italic> in Sarasota Bay, USA). Using a log‐linear model, we estimated the total body lengths (TL) of 160 known‐aged dolphins between 2021 and 2023 from blowhole‐to‐dorsal‐fin distance (BHDF) measurements collected during surfacing. Subsequently, we tested four growth models to establish an age‐length growth curve. We assessed the sub‐population's age‐structure using three methods: (1) UAS‐derived TL estimates, (2) age‐length growth curve and (3) long‐term monitoring data (i.e. actual age‐structure). UAS‐measured TL (247.6 ± 32.2 cm) and UAS‐estimated TL (246.0 ± 34.7 cm) of the Greek sub‐population showed no differences. The Richards Growth model suggested an asymptotic length of 258.5 cm. In Greece, resulting age‐structure estimates across the three methods revealed no significant differences (<jats:italic>P</jats:italic> > 0.1). The Gulf of Ambracia and Shark Bay populations shared similar age‐structures, while Sarasota had higher proportions of 2–10 year‐olds and lower proportions of 10+ year‐olds. All populations had a comparable proportion of 0–2 year‐olds (~14%), indicating a similar reproductive rate. Our findings suggest stability in the Greek sub‐population; however, additional monitoring of reproductive parameters is essential before concluding its status. We demonstrated the effectiveness of UAS‐photogrammetry in rapidly quantifying population age‐structure, including scenarios with limited or no demographic data. This technique shows promise for enhancing precision, timeliness, cost‐effectiveness and efficiency in population monitoring and informing timely conservation management decisions.","PeriodicalId":50786,"journal":{"name":"Animal Conservation","volume":"17 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142180685","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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