Elucidating the factors affecting the foraging habitat selection of wildlife can further our understanding of the animal–habitat relationships and inform wildlife conservation and management. Canopy and understory vegetation may directly or indirectly affect the foraging habitat selection of carnivores through changes in habitat structure and prey availability, respectively; however, the relative importance of these two effects remains largely unknown. Dwarf bamboo Sasa kurilensis is a predominant understory plant that suppresses regeneration in the forests of northern Japan. The purpose of this study was to disentangle the direct and indirect effects of canopy forest type Larix kaempferi plantation versus natural mixed forest) and dwarf bamboo on foraging habitat selection of a large carnivore, the brown bear Ursus arctos. In the Shiretoko World Heritage, brown bears dig for cicada nymphs during summer. We evaluated the frequency of brown bear foraging on cicadas by investigating traces of digging for cicada nymphs. A structural equation model was used to statistically disentangle the direct and indirect effects of vegetation. Our results demonstrated that canopy and understory vegetation directly and indirectly affected foraging habitat selection of brown bears. Dwarf bamboo negatively affected cicada nymph density, which positively affected brown bear digging. This suggests that dwarf bamboo also had indirect negative effects on brown bears. Forest type had significant direct and indirect effects via change in cicada nymph density on foraging behavior in brown bears. Forestry managers in northern Japan, including the study site, try to remove dwarf bamboo for assisting natural regeneration. Removal of dwarf bamboo by scarification might not only promote natural regeneration, but also provide a beneficial foraging habitat for bears.
{"title":"Disentangling the direct and indirect effects of canopy and understory vegetation on the foraging habitat selection of the brown bear Ursus arctos","authors":"K. Tomita, T. Hiura","doi":"10.2981/wlb.00886","DOIUrl":"https://doi.org/10.2981/wlb.00886","url":null,"abstract":"Elucidating the factors affecting the foraging habitat selection of wildlife can further our understanding of the animal–habitat relationships and inform wildlife conservation and management. Canopy and understory vegetation may directly or indirectly affect the foraging habitat selection of carnivores through changes in habitat structure and prey availability, respectively; however, the relative importance of these two effects remains largely unknown. Dwarf bamboo Sasa kurilensis is a predominant understory plant that suppresses regeneration in the forests of northern Japan. The purpose of this study was to disentangle the direct and indirect effects of canopy forest type Larix kaempferi plantation versus natural mixed forest) and dwarf bamboo on foraging habitat selection of a large carnivore, the brown bear Ursus arctos. In the Shiretoko World Heritage, brown bears dig for cicada nymphs during summer. We evaluated the frequency of brown bear foraging on cicadas by investigating traces of digging for cicada nymphs. A structural equation model was used to statistically disentangle the direct and indirect effects of vegetation. Our results demonstrated that canopy and understory vegetation directly and indirectly affected foraging habitat selection of brown bears. Dwarf bamboo negatively affected cicada nymph density, which positively affected brown bear digging. This suggests that dwarf bamboo also had indirect negative effects on brown bears. Forest type had significant direct and indirect effects via change in cicada nymph density on foraging behavior in brown bears. Forestry managers in northern Japan, including the study site, try to remove dwarf bamboo for assisting natural regeneration. Removal of dwarf bamboo by scarification might not only promote natural regeneration, but also provide a beneficial foraging habitat for bears.","PeriodicalId":54405,"journal":{"name":"Wildlife Biology","volume":"2021 1","pages":"wlb.00886"},"PeriodicalIF":1.9,"publicationDate":"2021-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41514313","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Kiki, C. Astaras, R. Montgomery, P. Henschel, A. Tehou, D. Macdonald, H. Bauer
Conflict with humans and habitat fragmentation are major threats to large carnivores in Africa, and transboundary protected areas may ease some of the space requirements for individual countries. The W-Arly-Pendjari complex (WAP) in West Africa sits across Benin, Burkina Faso and Niger and is the last regional stronghold for many species, including the regionally critically endangered lion Panthera leo. However, variation in monitoring efforts, limited resources and imperfect coordination confound their conservation. We demonstrate a cost-effective and scalable design to effectively identify the landscape-level factors that limit the distribution and abundance of large carnivores and their preferred prey. We used an occupancy framework for a combination of spoor and line transect data. We found a high degree of variation in prey density, strongly related to evapotranspiration. Lion occupancy increased in areas of high riparian forest cover, far from hunting concessions and with more pastoralist activities. Hyaena occupancy was inversely related to anthropogenic pressures, and positively related to dense vegetation and overall prey density. We discuss conservation challenges such as illegal hunting and grazing in the context of transboundary management.
{"title":"Cost effective assessment of human and habitat factors essential for critically endangered lions in West Africa","authors":"M. Kiki, C. Astaras, R. Montgomery, P. Henschel, A. Tehou, D. Macdonald, H. Bauer","doi":"10.2981/wlb.00848","DOIUrl":"https://doi.org/10.2981/wlb.00848","url":null,"abstract":"Conflict with humans and habitat fragmentation are major threats to large carnivores in Africa, and transboundary protected areas may ease some of the space requirements for individual countries. The W-Arly-Pendjari complex (WAP) in West Africa sits across Benin, Burkina Faso and Niger and is the last regional stronghold for many species, including the regionally critically endangered lion Panthera leo. However, variation in monitoring efforts, limited resources and imperfect coordination confound their conservation. We demonstrate a cost-effective and scalable design to effectively identify the landscape-level factors that limit the distribution and abundance of large carnivores and their preferred prey. We used an occupancy framework for a combination of spoor and line transect data. We found a high degree of variation in prey density, strongly related to evapotranspiration. Lion occupancy increased in areas of high riparian forest cover, far from hunting concessions and with more pastoralist activities. Hyaena occupancy was inversely related to anthropogenic pressures, and positively related to dense vegetation and overall prey density. We discuss conservation challenges such as illegal hunting and grazing in the context of transboundary management.","PeriodicalId":54405,"journal":{"name":"Wildlife Biology","volume":"2021 1","pages":"wlb.00848"},"PeriodicalIF":1.9,"publicationDate":"2021-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48879263","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Several ground-nesting bird species living in European farmlands are experiencing a persistent decline. Poorer reproductive success is suspected to be the main demographic driver. We developed a model to quantify to what extent such recent change may impact the viability of their populations. We took the grey partridge Perdix perdix, a typical farmland species, as a well-documented case study, but the model can be adapted to other species. We built a model based on our in-depth demographic knowledge of this species and the large database compiled from our long-term population monitoring programme. We took into account environmental and demographic stochasticity as well as density-dependence processes. We investigated the impact of recent changes in reproductive success on the viability of (unharvested) populations. For this purpose, we considered two periods: 1979–2004 as ‘Past’ and 2005–2014 as ‘Present’ (we used data of subsequent years to test the model’s goodness of fit). During the ‘Past’ period, the simulated population was increasing with a mean stochastic growth rate λmean = 1.01 (25% of decreasing trajectories), whereas λmean = 0.89 during the ‘Present’ period (74% of decreasing trajectories). We provide detailed results and discuss the possible environmental causes, with a focus on extreme weather events. In a further step, we used our model as a tool to investigate the impact of four hunting bag management strategies on exploited populations. The hunting bag was assumed to be an additive cause of mortality. Hunting leads to a decrease in λmean but the amplitude (from minor to substantial) depends upon the strategy and the setting-up of parameters. We deliver our model as a tool to support decision-making for sustainable population management and provide the script (ULM software) as Supplementary information.
{"title":"Recent changes in the reproductive success of farmland birds: conservation and management implications. The declining grey partridge Perdix perdix as a case study","authors":"Sylvain Godin, F. Reitz, Léo Bacon, E. Bro","doi":"10.2981/wlb.00806","DOIUrl":"https://doi.org/10.2981/wlb.00806","url":null,"abstract":"Several ground-nesting bird species living in European farmlands are experiencing a persistent decline. Poorer reproductive success is suspected to be the main demographic driver. We developed a model to quantify to what extent such recent change may impact the viability of their populations. We took the grey partridge Perdix perdix, a typical farmland species, as a well-documented case study, but the model can be adapted to other species. We built a model based on our in-depth demographic knowledge of this species and the large database compiled from our long-term population monitoring programme. We took into account environmental and demographic stochasticity as well as density-dependence processes. We investigated the impact of recent changes in reproductive success on the viability of (unharvested) populations. For this purpose, we considered two periods: 1979–2004 as ‘Past’ and 2005–2014 as ‘Present’ (we used data of subsequent years to test the model’s goodness of fit). During the ‘Past’ period, the simulated population was increasing with a mean stochastic growth rate λmean = 1.01 (25% of decreasing trajectories), whereas λmean = 0.89 during the ‘Present’ period (74% of decreasing trajectories). We provide detailed results and discuss the possible environmental causes, with a focus on extreme weather events. In a further step, we used our model as a tool to investigate the impact of four hunting bag management strategies on exploited populations. The hunting bag was assumed to be an additive cause of mortality. Hunting leads to a decrease in λmean but the amplitude (from minor to substantial) depends upon the strategy and the setting-up of parameters. We deliver our model as a tool to support decision-making for sustainable population management and provide the script (ULM software) as Supplementary information.","PeriodicalId":54405,"journal":{"name":"Wildlife Biology","volume":"2021 1","pages":"wlb.00806"},"PeriodicalIF":1.9,"publicationDate":"2021-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47120188","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Solène Marion, Urška Demšar, Althea L. Davies, P. Stephens, R. Irvine, J. Long
Outdoor recreation has the potential to impact the spatial and temporal distribution of animals. We explore interactions between red deer Cervus elaphus and hikers along a popular hiking path in the Scottish Highlands. We placed camera traps in transects at different distances (25, 75 and 150 m) from the path to study whether distance from hiker activity influences the number of deer detected. We compared this with the detection of red deer in an additional, spatially isolated area (one km away from any other transects and the hiking path). We collected count data on hikers at the start of the path and explored hourly (red deer detection during daytime), daily, diurnal (day versus night) and monthly spatial distributions of red deer. Using generalized linear mixed models with forward model selection, we found that the distribution of deer changed with the hiking activity. We found that fewer red deer were detected during busy hourly hiking periods. We found that during daytime, more red deer were detected at 150 m than at 25 m. Moreover, during the day, red deer were detected at a greater rate in the isolated area than around the transects close to the path and more likely to be found close to the path at night. This suggests that avoidance of hikers by red deer, in this study area, takes place over distances greater than 75 m and that red deer are displaced into less disturbed areas when the hiking path is busy. Our results suggest that the impact of hikers is short-term, as deer return to the disturbed areas during the night.
{"title":"Red deer exhibit spatial and temporal responses to hiking activity","authors":"Solène Marion, Urška Demšar, Althea L. Davies, P. Stephens, R. Irvine, J. Long","doi":"10.2981/wlb.00853","DOIUrl":"https://doi.org/10.2981/wlb.00853","url":null,"abstract":"Outdoor recreation has the potential to impact the spatial and temporal distribution of animals. We explore interactions between red deer Cervus elaphus and hikers along a popular hiking path in the Scottish Highlands. We placed camera traps in transects at different distances (25, 75 and 150 m) from the path to study whether distance from hiker activity influences the number of deer detected. We compared this with the detection of red deer in an additional, spatially isolated area (one km away from any other transects and the hiking path). We collected count data on hikers at the start of the path and explored hourly (red deer detection during daytime), daily, diurnal (day versus night) and monthly spatial distributions of red deer. Using generalized linear mixed models with forward model selection, we found that the distribution of deer changed with the hiking activity. We found that fewer red deer were detected during busy hourly hiking periods. We found that during daytime, more red deer were detected at 150 m than at 25 m. Moreover, during the day, red deer were detected at a greater rate in the isolated area than around the transects close to the path and more likely to be found close to the path at night. This suggests that avoidance of hikers by red deer, in this study area, takes place over distances greater than 75 m and that red deer are displaced into less disturbed areas when the hiking path is busy. Our results suggest that the impact of hikers is short-term, as deer return to the disturbed areas during the night.","PeriodicalId":54405,"journal":{"name":"Wildlife Biology","volume":"2021 1","pages":"wlb.00853"},"PeriodicalIF":1.9,"publicationDate":"2021-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43636973","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Capture and handling of wildlife is an important component of wildlife studies, and hunting can be a central tool for wildlife management. However, human-caused disturbance of animals can cause various negative effects on individuals. Thus, an increased understanding of different disturbances on animals will allow improved mitigation of human stressors for wildlife, and provides the basis for data-censoring when using information obtained from captured individuals. Here, we investigated the effects of capture and handling, as well as experimental disturbance, on the movement behavior of GPS-collared European hares Lepus europaeus. Of 28 hares captured in box traps, three died during handling to fit GPS collars, likely due to acute stress. Apart from an 11% decrease in activity in both sexes the first four days after capture compared to later, capture events had no significant effects on subsequent movement behavior. Hares that were disturbed experimentally, i.e. flushed with or without a shotgun shot fired, moved on average (± SD) 422 ± 206 m directly subsequent to the disturbance, leading to a spatial displacement of their short-term home range and an increased daily home range size on the disturbance day. Home range sizes returned to their before disturbance size on the following days, but hares remained further from field edges and spent more time in short vegetation in the days after simulated hunting, though this effect was comparatively small. Overall, our findings indicate that hares only marginally changed their movement behavior in response to short-term disturbances. Therefore, capture and hunting disturbance should not have severe negative effects on the movement behavior of individuals, but future studies should aim to reduce acute capture-related stress to avoid mortalities. We recommend that researchers should censor the first four days after capture from their analyses to avoid using potentially biased data.
{"title":"Scared as a hare: effects of capture and experimental disturbance on survival and movement behavior of European hares","authors":"M. Mayer, Lars Haugaard, P. Sunde","doi":"10.2981/wlb.00840","DOIUrl":"https://doi.org/10.2981/wlb.00840","url":null,"abstract":"Capture and handling of wildlife is an important component of wildlife studies, and hunting can be a central tool for wildlife management. However, human-caused disturbance of animals can cause various negative effects on individuals. Thus, an increased understanding of different disturbances on animals will allow improved mitigation of human stressors for wildlife, and provides the basis for data-censoring when using information obtained from captured individuals. Here, we investigated the effects of capture and handling, as well as experimental disturbance, on the movement behavior of GPS-collared European hares Lepus europaeus. Of 28 hares captured in box traps, three died during handling to fit GPS collars, likely due to acute stress. Apart from an 11% decrease in activity in both sexes the first four days after capture compared to later, capture events had no significant effects on subsequent movement behavior. Hares that were disturbed experimentally, i.e. flushed with or without a shotgun shot fired, moved on average (± SD) 422 ± 206 m directly subsequent to the disturbance, leading to a spatial displacement of their short-term home range and an increased daily home range size on the disturbance day. Home range sizes returned to their before disturbance size on the following days, but hares remained further from field edges and spent more time in short vegetation in the days after simulated hunting, though this effect was comparatively small. Overall, our findings indicate that hares only marginally changed their movement behavior in response to short-term disturbances. Therefore, capture and hunting disturbance should not have severe negative effects on the movement behavior of individuals, but future studies should aim to reduce acute capture-related stress to avoid mortalities. We recommend that researchers should censor the first four days after capture from their analyses to avoid using potentially biased data.","PeriodicalId":54405,"journal":{"name":"Wildlife Biology","volume":"2021 1","pages":"wlb.00840"},"PeriodicalIF":1.9,"publicationDate":"2021-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49412774","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mapping habitat selection by threatened species provides critical information for conservation planning. For reintroduced populations, understanding habitat selection is also necessary to predict dispersal and inform selection of new reintroduction sites. Efforts to restore bison Bison bison to the boreal forest hinge on the persistence of geographically isolated populations that occupy diverse landscapes, and for many populations selected habitats are unknown. We used location data from GPS-collared bison to develop seasonal resource selection function (RSF) models and predictive maps for the reintroduced ‘Nahanni’ population. We accounted for variation in individual behaviour by calculating averaged population-level selection coefficients from individual RSFs, and we compared these results to a pooled RSF from all bison. Individual RSFs revealed variation in habitat selection that was not always captured by the pooled RSF, although there were some consistencies. Bison strongly selected forage-rich graminoid-dominated wetlands (fens) during winter, but less so in summer when there were potential tradeoffs with poor footing and biting flies. In summer, bison selected alternative sources of forage such as herbaceous, shrubby and fluvial habitats (i.e. riverine islands and gravel bars). The observed association with fluvial habitat may be an adaptation to low forage availability on this landscape. Bison also selected roads and anthropogenic clearings associated with resource development, demonstrating potential for human–wildlife conflict. Our predictive maps highlight areas of conservation interest, and should be considered in land use planning and environmental assessments. We demonstrate the value of foraging habitat for forest-dwelling bison, particularly in winter. Identifying forage-rich habitat patches, and connectivity between them, is important when considering sites for new reintroductions or expansion of existing populations. More broadly, our approach may be used to identify areas of high conservation interest, where resources do not allow extensive sample sizes of GPS-collared animals.
{"title":"Individual-based seasonal habitat selection in a forest-dwelling population of reintroduced bison Bison bison","authors":"Julie P. Thomas, N. Larter, T. Jung","doi":"10.2981/wlb.00852","DOIUrl":"https://doi.org/10.2981/wlb.00852","url":null,"abstract":"Mapping habitat selection by threatened species provides critical information for conservation planning. For reintroduced populations, understanding habitat selection is also necessary to predict dispersal and inform selection of new reintroduction sites. Efforts to restore bison Bison bison to the boreal forest hinge on the persistence of geographically isolated populations that occupy diverse landscapes, and for many populations selected habitats are unknown. We used location data from GPS-collared bison to develop seasonal resource selection function (RSF) models and predictive maps for the reintroduced ‘Nahanni’ population. We accounted for variation in individual behaviour by calculating averaged population-level selection coefficients from individual RSFs, and we compared these results to a pooled RSF from all bison. Individual RSFs revealed variation in habitat selection that was not always captured by the pooled RSF, although there were some consistencies. Bison strongly selected forage-rich graminoid-dominated wetlands (fens) during winter, but less so in summer when there were potential tradeoffs with poor footing and biting flies. In summer, bison selected alternative sources of forage such as herbaceous, shrubby and fluvial habitats (i.e. riverine islands and gravel bars). The observed association with fluvial habitat may be an adaptation to low forage availability on this landscape. Bison also selected roads and anthropogenic clearings associated with resource development, demonstrating potential for human–wildlife conflict. Our predictive maps highlight areas of conservation interest, and should be considered in land use planning and environmental assessments. We demonstrate the value of foraging habitat for forest-dwelling bison, particularly in winter. Identifying forage-rich habitat patches, and connectivity between them, is important when considering sites for new reintroductions or expansion of existing populations. More broadly, our approach may be used to identify areas of high conservation interest, where resources do not allow extensive sample sizes of GPS-collared animals.","PeriodicalId":54405,"journal":{"name":"Wildlife Biology","volume":"2021 1","pages":"wlb.00852"},"PeriodicalIF":1.9,"publicationDate":"2021-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44800759","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Guillemain, David Vallecillo, Emilienne Grzegorczyk, J. Mouronval, M. Gauthier‐Clerc, A. Tamisier, J. Champagnon
The European Birds Directive (EBD) prevents hunting during spring migration, primarily to facilitate birds' use of habitats before and during the prenuptial journey. In line with the EBD requirements, the hunting season for waterfowl in southern France was shortened by two months during February–March since the mid-1950s. However, consequences of such hunting bans for late winter habitat use have not been evaluated. We investigated a 55-years dataset from a major international wintering ground to assess whether the EBD-related changes in hunting legislation have led to increased regional teal Anas crecca numbers during late winter. Teal abundance in the Camargue during late winter increased over the last decades: the ban on hunting in February was the best predictor of teal numbers during that month, leading to a sudden 50% increase in relative abundance. In March a more gradual temporal increase since the mid-1960 was instead recorded. Whether the increase in teal during late winter resulted from locally wintering birds or those from elsewhere stopping in the Camargue cannot be discerned. Nonetheless, the increase in teal numbers supports the basis for the EBD, in that a ban on hunting during late winter is associated with a greater use of habitats during this crucial part of the annual cycle, especially in February.
{"title":"Consequences of shortened hunting seasons by the Birds Directive on late winter teal Anas crecca abundance in France","authors":"M. Guillemain, David Vallecillo, Emilienne Grzegorczyk, J. Mouronval, M. Gauthier‐Clerc, A. Tamisier, J. Champagnon","doi":"10.2981/wlb.00845","DOIUrl":"https://doi.org/10.2981/wlb.00845","url":null,"abstract":"The European Birds Directive (EBD) prevents hunting during spring migration, primarily to facilitate birds' use of habitats before and during the prenuptial journey. In line with the EBD requirements, the hunting season for waterfowl in southern France was shortened by two months during February–March since the mid-1950s. However, consequences of such hunting bans for late winter habitat use have not been evaluated. We investigated a 55-years dataset from a major international wintering ground to assess whether the EBD-related changes in hunting legislation have led to increased regional teal Anas crecca numbers during late winter. Teal abundance in the Camargue during late winter increased over the last decades: the ban on hunting in February was the best predictor of teal numbers during that month, leading to a sudden 50% increase in relative abundance. In March a more gradual temporal increase since the mid-1960 was instead recorded. Whether the increase in teal during late winter resulted from locally wintering birds or those from elsewhere stopping in the Camargue cannot be discerned. Nonetheless, the increase in teal numbers supports the basis for the EBD, in that a ban on hunting during late winter is associated with a greater use of habitats during this crucial part of the annual cycle, especially in February.","PeriodicalId":54405,"journal":{"name":"Wildlife Biology","volume":"2021 1","pages":"wlb.00845"},"PeriodicalIF":1.9,"publicationDate":"2021-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49547191","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
For the ability to control an invasive species and to protect an ecologically similar native species it is essential to map the exact distributions of both species. This is difficult if the species are so morphologically similar that their identification in the field is almost impossible. In Finland, the invasive North American beaver Castor canadensis is spreading towards the range of the native Eurasian beaver Castor fiber and at present, these species are partly sympatric. Effective management of these morphologically similar species requires an efficient method for species identification, ideally one that is non-invasive. Non-invasive genetic methods are used in a wide variety of wildlife species, for example in the research of large carnivores. Feces are a good source of DNA for terrestrial animals, but for the semi-aquatic animals like beavers, feces are not the best option. However, environmental DNA (eDNA) has been successfully used to detect species non-invasively in aquatic and terrestrial environments. We developed a non-invasive, eDNA-based method to map the distribution of the beaver species in Finland and to investigate within-species genetic diversity. The eDNA was obtained from the feed remains (wood chips) from beaver forage sites. With the help of Citizen science, wood chip samples were collected from different parts of Finland. We used our eDNA method to identify the ranges of both beaver species. Additionally, the presence of Eurasian beavers in south-east Finland was proven for the first time. Our non-invasive eDNA method is an effective way to accurately identify the ranges of both beaver species and will allow for the control of the invasive North American beaver and conservation of the native Eurasian beaver in Finland.
{"title":"A non-invasive, DNA-based method for beaver species identification in Finland","authors":"T. Iso-Touru, J. Tabell, A. Virta, K. Kauhala","doi":"10.2981/wlb.00808","DOIUrl":"https://doi.org/10.2981/wlb.00808","url":null,"abstract":"For the ability to control an invasive species and to protect an ecologically similar native species it is essential to map the exact distributions of both species. This is difficult if the species are so morphologically similar that their identification in the field is almost impossible. In Finland, the invasive North American beaver Castor canadensis is spreading towards the range of the native Eurasian beaver Castor fiber and at present, these species are partly sympatric. Effective management of these morphologically similar species requires an efficient method for species identification, ideally one that is non-invasive. Non-invasive genetic methods are used in a wide variety of wildlife species, for example in the research of large carnivores. Feces are a good source of DNA for terrestrial animals, but for the semi-aquatic animals like beavers, feces are not the best option. However, environmental DNA (eDNA) has been successfully used to detect species non-invasively in aquatic and terrestrial environments. We developed a non-invasive, eDNA-based method to map the distribution of the beaver species in Finland and to investigate within-species genetic diversity. The eDNA was obtained from the feed remains (wood chips) from beaver forage sites. With the help of Citizen science, wood chip samples were collected from different parts of Finland. We used our eDNA method to identify the ranges of both beaver species. Additionally, the presence of Eurasian beavers in south-east Finland was proven for the first time. Our non-invasive eDNA method is an effective way to accurately identify the ranges of both beaver species and will allow for the control of the invasive North American beaver and conservation of the native Eurasian beaver in Finland.","PeriodicalId":54405,"journal":{"name":"Wildlife Biology","volume":"2021 1","pages":"wlb.00808"},"PeriodicalIF":1.9,"publicationDate":"2021-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47059629","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
P. Söderquist, L. Dessborn, Henric Djerf, J. Elmberg, G. Gunnarsson, S. Holopainen
Common practices in current game management are wetland restoration and creation, as well as releases of quarry species. We studied the impact of releases of mallard ducklings on species richness of wild waterbirds and amphibians on three types of wetlands: natural, constructed and restored. Data on species richness, macrophyte cover and water characteristics (total phosphorous and pH) were collected at 32 sites in an agricultural landscape in southern Sweden. In total, 14 species of waterbirds were recorded, ranging from zero to seven per wetland and survey. Amphibians were present in 24 of the 32 wetlands; in total five species were found, ranging from zero to three per wetland. By using generalized linear modelling we found that wetland type best predicted waterbird species richness. Constructed wetlands had significantly more waterbird species, regardless of whether they were used for mallard releases or not. There were breeding amphibians in 62% of natural, 100% of restored and 77% of constructed wetlands. Breeding amphibians were present in 84% of wetlands without, and in 62% of wetlands with releases. However, included variables did not explain amphibian species richness in the wetlands. Releasing large numbers of mallards on a wetland and providing food ad libitum is likely to affect water quality, nutrient availability and predation pressure. Indeed, phosphorous levels were significantly higher in release wetlands, but no differences were found between wetland types.This means that mallard releases may increase nutrient loads in environments that are already eutrophied. However, in our study system releases did not influence species richness of waterbirds and amphibians locally. Constructing wetlands for mallard releases can thus have positive local effects on species richness.
{"title":"Effects of released farmed mallards on species richness of breeding waterbirds and amphibians in natural, restored and constructed wetlands","authors":"P. Söderquist, L. Dessborn, Henric Djerf, J. Elmberg, G. Gunnarsson, S. Holopainen","doi":"10.2981/wlb.00846","DOIUrl":"https://doi.org/10.2981/wlb.00846","url":null,"abstract":"Common practices in current game management are wetland restoration and creation, as well as releases of quarry species. We studied the impact of releases of mallard ducklings on species richness of wild waterbirds and amphibians on three types of wetlands: natural, constructed and restored. Data on species richness, macrophyte cover and water characteristics (total phosphorous and pH) were collected at 32 sites in an agricultural landscape in southern Sweden. In total, 14 species of waterbirds were recorded, ranging from zero to seven per wetland and survey. Amphibians were present in 24 of the 32 wetlands; in total five species were found, ranging from zero to three per wetland. By using generalized linear modelling we found that wetland type best predicted waterbird species richness. Constructed wetlands had significantly more waterbird species, regardless of whether they were used for mallard releases or not. There were breeding amphibians in 62% of natural, 100% of restored and 77% of constructed wetlands. Breeding amphibians were present in 84% of wetlands without, and in 62% of wetlands with releases. However, included variables did not explain amphibian species richness in the wetlands. Releasing large numbers of mallards on a wetland and providing food ad libitum is likely to affect water quality, nutrient availability and predation pressure. Indeed, phosphorous levels were significantly higher in release wetlands, but no differences were found between wetland types.This means that mallard releases may increase nutrient loads in environments that are already eutrophied. However, in our study system releases did not influence species richness of waterbirds and amphibians locally. Constructing wetlands for mallard releases can thus have positive local effects on species richness.","PeriodicalId":54405,"journal":{"name":"Wildlife Biology","volume":"2021 1","pages":"wlb.00846"},"PeriodicalIF":1.9,"publicationDate":"2021-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41830735","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Carlos P. E. Bedson, Lowri Thomas, P. Wheeler, N. Reid, W. E. Harris, H. Lloyd, D. Mallon, R. Preziosi
Surveying cryptic, nocturnal animals is logistically challenging. Consequently, density estimates may be imprecise and uncertain. Survey innovations mitigate ecological and observational difficulties contributing to estimation variance. Thus, comparisons of survey techniques are critical to evaluate estimates of abundance. We simultaneously compared three methods for observing mountain hare Lepus timidus using Distance sampling to estimate abundance. Daylight visual surveys achieved 41 detections, estimating density at 14.3 hares km–2 (95%CI 6.3–32.5) resulting in the lowest estimate and widest confidence interval. Night-time thermal imaging achieved 206 detections, estimating density at 12.1 hares km–2 (95%CI 7.6–19.4). Thermal imaging captured more observations at furthest distances, and detected larger group sizes. Camera traps achieved 3705 night-time detections, estimating density at 22.6 hares km–2 (95%CI 17.1–29.9). Between the methods, detections were spatially correlated, although the estimates of density varied. Our results suggest that daylight visual surveys tended to underestimate density, failing to reflect nocturnal activity. Thermal imaging captured nocturnal activity, providing a higher detection rate, but required fine weather. Camera traps captured nocturnal activity, and operated 24/7 throughout harsh weather, but needed careful consideration of empirical assumptions. We discuss the merits and limitations of each method with respect to the estimation of population density in the field.
{"title":"Estimating density of mountain hares using distance sampling: a comparison of daylight visual surveys, night-time thermal imaging and camera traps","authors":"Carlos P. E. Bedson, Lowri Thomas, P. Wheeler, N. Reid, W. E. Harris, H. Lloyd, D. Mallon, R. Preziosi","doi":"10.2981/wlb.00802","DOIUrl":"https://doi.org/10.2981/wlb.00802","url":null,"abstract":"Surveying cryptic, nocturnal animals is logistically challenging. Consequently, density estimates may be imprecise and uncertain. Survey innovations mitigate ecological and observational difficulties contributing to estimation variance. Thus, comparisons of survey techniques are critical to evaluate estimates of abundance. We simultaneously compared three methods for observing mountain hare Lepus timidus using Distance sampling to estimate abundance. Daylight visual surveys achieved 41 detections, estimating density at 14.3 hares km–2 (95%CI 6.3–32.5) resulting in the lowest estimate and widest confidence interval. Night-time thermal imaging achieved 206 detections, estimating density at 12.1 hares km–2 (95%CI 7.6–19.4). Thermal imaging captured more observations at furthest distances, and detected larger group sizes. Camera traps achieved 3705 night-time detections, estimating density at 22.6 hares km–2 (95%CI 17.1–29.9). Between the methods, detections were spatially correlated, although the estimates of density varied. Our results suggest that daylight visual surveys tended to underestimate density, failing to reflect nocturnal activity. Thermal imaging captured nocturnal activity, providing a higher detection rate, but required fine weather. Camera traps captured nocturnal activity, and operated 24/7 throughout harsh weather, but needed careful consideration of empirical assumptions. We discuss the merits and limitations of each method with respect to the estimation of population density in the field.","PeriodicalId":54405,"journal":{"name":"Wildlife Biology","volume":"2021 1","pages":"wlb.00802"},"PeriodicalIF":1.9,"publicationDate":"2021-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43326028","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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