Context: The common pigeon (Columba livia var. domestica) is a synurbic species widely distributed around the world. High local densities of pigeons have negative impacts on animal and public health. Urban pigeon fouling also damages buildings and infrastructures, resulting in increased maintenance costs. Although the reduction of food and shelter would be the most effective control method, it does not apply in most cases where the amount of shelter and food can be unlimited and control very difficult achieve. However, a reduction and control of the population by fertility control using nicarbazin (NCZ, Ovistop®) could be achieved without the need to capture and remove any specimens.
Aim and methods: The aims of this study were (1) to describe the experience of up to 8 years of use of fertility control by NCZ on pigeon numbers in 24 towns and cities in Catalonia (Spain), (2) to assess the potential for non-target species to be affected by NCZ, and (3) to quantify the costs of implementing local population control of urban pigeons via NCZ. Local number of pigeons was estimated via population censuses.
Key results: From the beginning of the treatment, a significant steady decreasing trend (average of −12% per year) in the pigeon abundance was registered. In very few instances, non-target birds species were observed to feed on NCZ.
Conclusions and implications: NZC was an effective and selective method of animal welfare to reduce the total number of pigeons in the municipalities included in this study, while not affecting other non-target species. The estimated cost of the annual treatment was €33.6 per pigeon; in 68% of the municipalities, the total annual cost was halved after 3 years of treatment. The findings of this study are in agreement with previous experiences controlling pigeon colonies by using NCZ in other countries.
背景:普通鸽子(Columba livia var. domestica)是一种广泛分布在世界各地的共尿种。当地鸽子密度高对动物和公众健康有负面影响。城市鸽子污染还会破坏建筑物和基础设施，导致维护成本增加。虽然减少食物和住所是最有效的控制方法，但它并不适用于大多数情况，因为住房和食物的数量是无限的，而且很难实现控制。然而，通过使用尼卡巴嗪(NCZ, Ovistop®)的生育控制可以实现种群的减少和控制，而无需捕获和移除任何标本。目的和方法:本研究的目的是:(1)描述在加泰罗尼亚(西班牙)的24个城镇中，NCZ对鸽子数量进行长达8年的生育控制的经验，(2)评估NCZ对非目标物种的潜在影响，(3)量化通过NCZ实施当地城市鸽子种群控制的成本。通过人口普查估计了当地鸽子的数量。关键结果:从处理开始，鸽子数量呈显著稳定下降趋势(平均每年- 12%)。在极少数情况下，观察到非目标鸟类以NCZ为食。结论和意义:NZC是一种有效的、选择性的动物福利方法，在不影响其他非目标物种的情况下，减少了所研究城市的鸽子总数。每年的治疗费用估计为每只鸽子33.6欧元;在68%的市镇，经过3年的治疗，年总费用减少了一半。本研究结果与其他国家利用NCZ控制鸽群的经验一致。
{"title":"Evaluation of 8 years of fertility control (nicarbazin) to manage urban pigeon populations","authors":"Carlos González-Crespo","doi":"10.1071/wr22166","DOIUrl":"https://doi.org/10.1071/wr22166","url":null,"abstract":"<p><b>Context: </b>The common pigeon (<i>Columba livia var. domestica</i>) is a synurbic species widely distributed around the world. High local densities of pigeons have negative impacts on animal and public health. Urban pigeon fouling also damages buildings and infrastructures, resulting in increased maintenance costs. Although the reduction of food and shelter would be the most effective control method, it does not apply in most cases where the amount of shelter and food can be unlimited and control very difficult achieve. However, a reduction and control of the population by fertility control using nicarbazin (NCZ, Ovistop®) could be achieved without the need to capture and remove any specimens.</p><p><b>Aim and methods: </b>The aims of this study were (1) to describe the experience of up to 8 years of use of fertility control by NCZ on pigeon numbers in 24 towns and cities in Catalonia (Spain), (2) to assess the potential for non-target species to be affected by NCZ, and (3) to quantify the costs of implementing local population control of urban pigeons via NCZ. Local number of pigeons was estimated via population censuses.</p><p><b>Key results: </b>From the beginning of the treatment, a significant steady decreasing trend (average of −12% per year) in the pigeon abundance was registered. In very few instances, non-target birds species were observed to feed on NCZ.</p><p><b>Conclusions and implications: </b>NZC was an effective and selective method of animal welfare to reduce the total number of pigeons in the municipalities included in this study, while not affecting other non-target species. The estimated cost of the annual treatment was €33.6 per pigeon; in 68% of the municipalities, the total annual cost was halved after 3 years of treatment. The findings of this study are in agreement with previous experiences controlling pigeon colonies by using NCZ in other countries.</p>","PeriodicalId":23971,"journal":{"name":"Wildlife Research","volume":"27 1","pages":""},"PeriodicalIF":1.9,"publicationDate":"2023-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138540469","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}
E. Hill, N. Murphy, A. Linacre, Simon D. Toop, J. Strugnell
ABSTRACT Context A wild population of non-native hog deer has established in the Gippsland region of Victoria, Australia, and there is particular concern about its impact on native vegetation in Wilsons Promontory National Park (WPNP). Since 2015, there has been annual culling of hog deer at WPNP to reduce deer abundances and impacts. Aim The aims of this study were to use a kinship approach based on genotyping to assess contemporary dispersal of hog deer across WPNP, by identifying close kin, to determine whether dispersal of deer into culled sites from unculled sites may affect the long-term success of management there. Differences in the dispersal of male and female hog deer were also investigated. Methods In total, 91 hog deer tissue samples were collected across WPNP and surrounding sites. Single nucleotide polymorphism (SNP) markers were sequenced, and a final dataset comprising 8275 SNPs was used for analysis. First-order, second-order, and intermediate relative pairs were identified, and the geographic distance between these pairs was assessed to determine inter-pair distances to infer dispersal. Spatial autocorrelation between male and female samples was evaluated to measure the effects of sex-biased dispersal. Key results Only seven second-order relative pairs were found across different sites, with a 30 km distance between the furthest pair observed. However, most inter-pair distances across sites were ~5–10 km. Analyses of sex-biased dispersal showed that movement by deer was not strongly influenced by one sex. Conclusions Although hog deer in WPNP are genetically similar, most relatives that were sampled were not widely dispersed. This suggests that there is limited dispersal of hog deer across this park. Implications Recolonisation of hog deer at culled sites via dispersal is likely to be infrequent in WPNP. Kinship analysis provides an effective method of assessing contemporary dispersal and could be applied to other species to assess fine-scale movement across landscapes.
{"title":"Kinship analysis reveals low dispersal in a hog deer (Axis porcinus) population in Wilsons Promontory National Park, Australia","authors":"E. Hill, N. Murphy, A. Linacre, Simon D. Toop, J. Strugnell","doi":"10.1071/WR22098","DOIUrl":"https://doi.org/10.1071/WR22098","url":null,"abstract":"ABSTRACT Context A wild population of non-native hog deer has established in the Gippsland region of Victoria, Australia, and there is particular concern about its impact on native vegetation in Wilsons Promontory National Park (WPNP). Since 2015, there has been annual culling of hog deer at WPNP to reduce deer abundances and impacts. Aim The aims of this study were to use a kinship approach based on genotyping to assess contemporary dispersal of hog deer across WPNP, by identifying close kin, to determine whether dispersal of deer into culled sites from unculled sites may affect the long-term success of management there. Differences in the dispersal of male and female hog deer were also investigated. Methods In total, 91 hog deer tissue samples were collected across WPNP and surrounding sites. Single nucleotide polymorphism (SNP) markers were sequenced, and a final dataset comprising 8275 SNPs was used for analysis. First-order, second-order, and intermediate relative pairs were identified, and the geographic distance between these pairs was assessed to determine inter-pair distances to infer dispersal. Spatial autocorrelation between male and female samples was evaluated to measure the effects of sex-biased dispersal. Key results Only seven second-order relative pairs were found across different sites, with a 30 km distance between the furthest pair observed. However, most inter-pair distances across sites were ~5–10 km. Analyses of sex-biased dispersal showed that movement by deer was not strongly influenced by one sex. Conclusions Although hog deer in WPNP are genetically similar, most relatives that were sampled were not widely dispersed. This suggests that there is limited dispersal of hog deer across this park. Implications Recolonisation of hog deer at culled sites via dispersal is likely to be infrequent in WPNP. Kinship analysis provides an effective method of assessing contemporary dispersal and could be applied to other species to assess fine-scale movement across landscapes.","PeriodicalId":23971,"journal":{"name":"Wildlife Research","volume":"25 1","pages":"746 - 756"},"PeriodicalIF":1.9,"publicationDate":"2023-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72754400","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}
ABSTRACT Context Chital deer (Axis axis) are long established in the northern Queensland dry tropics, and at high densities are considered pests by cattle graziers. Cost-effective management is difficult for widespread, fluctuating populations of vertebrate pests such as these deer. Historically, control of chital deer has been limited to recreational and some commercial ground-shooting and trapping. Concerns over chital deer impacts were heightened during drought in 2015 and funding became available for aerial culling. Aim This study set out to determine (1) distribution and abundance, (2) seasonal reproductive output, (3) potential and actual rates of increase and their determinants, and (4) efficient management strategies for chital deer in the northern Queensland dry tropics. Methods In 2014, ~13 000 km2 of the main distribution was surveyed by helicopter. Multiple vehicle ground surveys per year monitored chital deer density on two properties during 2013–2022. Seasonal shot samples of deer on both properties assessed reproductive output during 2014–2016. Aerial surveys during 2016–2020 determined chital deer densities on seven properties, prior to aerial culling on four properties. Finally, the maximum rate of increase of chital deer was calculated from life-history data. Key results Regionally, chital deer are patchily distributed and so are best monitored locally where densities can be >50 deer km−2. Vehicle ground surveys recorded an ~80% decline in chital deer populations on two properties over 7–10 months during drought in early 2015, with a similar rate being recorded by aerial survey at a third site. There was little recruitment during the drought, but the decline was seemingly driven by adult mortality. Aerial shooting further reduced populations by 39–88% to <3 deer km−2 on four properties. Where there was no continuing control, culled populations recovered to pre-cull densities or higher after 2.4 years. One unculled property recovered to its pre-drought density after 6 years. Rates of recovery were at or higher than the maximum annual rate of increase for chital deer estimated here as 26–41%. Conclusions Drought has a lasting effect on this chital deer population, because of the resulting large population decline and the modest rate of any recovery in the absence of culling. Culling can reduce populations to low density, but the removal rate needs to be sustained to suppress future growth. Implications Drought provides a strategic opportunity to further reduce chital deer populations for enduring control. Large reductions are feasible given the clumped dispersion of populations within properties and in the region.
{"title":"Population dynamics of chital deer (Axis axis) in northern Queensland: effects of drought and culling","authors":"A. Pople, Matt Amos, M. Brennan","doi":"10.1071/WR22130","DOIUrl":"https://doi.org/10.1071/WR22130","url":null,"abstract":"ABSTRACT Context Chital deer (Axis axis) are long established in the northern Queensland dry tropics, and at high densities are considered pests by cattle graziers. Cost-effective management is difficult for widespread, fluctuating populations of vertebrate pests such as these deer. Historically, control of chital deer has been limited to recreational and some commercial ground-shooting and trapping. Concerns over chital deer impacts were heightened during drought in 2015 and funding became available for aerial culling. Aim This study set out to determine (1) distribution and abundance, (2) seasonal reproductive output, (3) potential and actual rates of increase and their determinants, and (4) efficient management strategies for chital deer in the northern Queensland dry tropics. Methods In 2014, ~13 000 km2 of the main distribution was surveyed by helicopter. Multiple vehicle ground surveys per year monitored chital deer density on two properties during 2013–2022. Seasonal shot samples of deer on both properties assessed reproductive output during 2014–2016. Aerial surveys during 2016–2020 determined chital deer densities on seven properties, prior to aerial culling on four properties. Finally, the maximum rate of increase of chital deer was calculated from life-history data. Key results Regionally, chital deer are patchily distributed and so are best monitored locally where densities can be >50 deer km−2. Vehicle ground surveys recorded an ~80% decline in chital deer populations on two properties over 7–10 months during drought in early 2015, with a similar rate being recorded by aerial survey at a third site. There was little recruitment during the drought, but the decline was seemingly driven by adult mortality. Aerial shooting further reduced populations by 39–88% to <3 deer km−2 on four properties. Where there was no continuing control, culled populations recovered to pre-cull densities or higher after 2.4 years. One unculled property recovered to its pre-drought density after 6 years. Rates of recovery were at or higher than the maximum annual rate of increase for chital deer estimated here as 26–41%. Conclusions Drought has a lasting effect on this chital deer population, because of the resulting large population decline and the modest rate of any recovery in the absence of culling. Culling can reduce populations to low density, but the removal rate needs to be sustained to suppress future growth. Implications Drought provides a strategic opportunity to further reduce chital deer populations for enduring control. Large reductions are feasible given the clumped dispersion of populations within properties and in the region.","PeriodicalId":23971,"journal":{"name":"Wildlife Research","volume":"31 1","pages":"728 - 745"},"PeriodicalIF":1.9,"publicationDate":"2023-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83742138","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}
ABSTRACT Context Aerial shooting from a helicopter targeting introduced sambar deer (Cervus unicolor) is a key activity being undertaken on public land in the North East and East Gippsland regions of Victoria. However, there is currently little published information on the efficacy of aerial shooting for reducing sambar deer populations in Australia. Aim The aims of this study were to analyse the operational data collected during an aerial shooting program in eastern Victoria, to assess the efficacy of aerial shooting at reducing sambar deer density and to inform management decisions on the required intensity of aerial shooting to achieve target densities. Methods Operational data (locations of all shot animals as well as aerial search effort) were analysed from 10 sites using a Bayesian generalised catch–effort model, which allowed for population changes between five periods of intensive control. The model allowed estimates of initial and residual abundance for each site to be made from the catch–effort data, which were used to estimate the efficacy of aerial shooting. Estimates of the detection rate of deer, which were allowed to vary with removal occasion and site, were then used to estimate the amount of aerial search effort required to reduce population densities by various proportional amounts. Key results Aerial shooting resulted in population reductions of 50–70% of sambar deer at four sites where aerial search intensities per unit area were highest. However, results at the remaining sites suggest that sambar deer densities have either remained static or increased over the five periods of aerial control. Recruitment of sambar deer between control periods, which was strongly influenced by study site elevation and season, was largely responsible for eroding reductions achieved by aerial shooting. Conclusions Catch–effort models applied to operational data collected during aerial shooting programs can be used to estimate control efficacy without the need for additional monitoring. Our analysis suggests that sufficiently high search intensities, around 1.4 km of search effort per km2 of habitat in each of five removal occasions, would need to be applied to achieve at least a 50% reduction in sambar deer densities.
{"title":"The application of catch–effort models to estimate the efficacy of aerial shooting operations on sambar deer (Cervus unicolor)","authors":"D. Ramsey, D. McMaster, E. Thomas","doi":"10.1071/WR22123","DOIUrl":"https://doi.org/10.1071/WR22123","url":null,"abstract":"ABSTRACT Context Aerial shooting from a helicopter targeting introduced sambar deer (Cervus unicolor) is a key activity being undertaken on public land in the North East and East Gippsland regions of Victoria. However, there is currently little published information on the efficacy of aerial shooting for reducing sambar deer populations in Australia. Aim The aims of this study were to analyse the operational data collected during an aerial shooting program in eastern Victoria, to assess the efficacy of aerial shooting at reducing sambar deer density and to inform management decisions on the required intensity of aerial shooting to achieve target densities. Methods Operational data (locations of all shot animals as well as aerial search effort) were analysed from 10 sites using a Bayesian generalised catch–effort model, which allowed for population changes between five periods of intensive control. The model allowed estimates of initial and residual abundance for each site to be made from the catch–effort data, which were used to estimate the efficacy of aerial shooting. Estimates of the detection rate of deer, which were allowed to vary with removal occasion and site, were then used to estimate the amount of aerial search effort required to reduce population densities by various proportional amounts. Key results Aerial shooting resulted in population reductions of 50–70% of sambar deer at four sites where aerial search intensities per unit area were highest. However, results at the remaining sites suggest that sambar deer densities have either remained static or increased over the five periods of aerial control. Recruitment of sambar deer between control periods, which was strongly influenced by study site elevation and season, was largely responsible for eroding reductions achieved by aerial shooting. Conclusions Catch–effort models applied to operational data collected during aerial shooting programs can be used to estimate control efficacy without the need for additional monitoring. Our analysis suggests that sufficiently high search intensities, around 1.4 km of search effort per km2 of habitat in each of five removal occasions, would need to be applied to achieve at least a 50% reduction in sambar deer densities.","PeriodicalId":23971,"journal":{"name":"Wildlife Research","volume":"12 1","pages":"688 - 700"},"PeriodicalIF":1.9,"publicationDate":"2023-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84263288","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}
D. Michael, D. Nimmo, E. Stevens, T. Schlen, S. Wassens
ABSTRACT Context. River regulation, coupled with climate change, has caused significant declines in global freshwater biodiversity. In Australia, water extraction within the Murray–Darling Basin (MDB) has reduced the frequency, extent and duration with which floodplains are inundated, resulting in widespread declines in wetland-dependent biodiversity, including reptiles. The endangered Ngabi (Hemiaspis damelii) is associated with floodplain systems in the MDB, yet its distribution and ecological requirements are poorly understood, hampering conservation actions. Aims. We sought to validate an assumption that Ngabi is associated with wetland vegetation communities before investigating factors affecting its probability of detection in the lower Murrumbidgee catchment in southern New South Wales. We predicted Ngabi occurrence patterns would relate to frog abundance, wetland hydrology, microhabitat attributes and meteorological variables. Methods. We compared Ngabi observations from 16 paired wetland and dryland vegetation transects to evaluate associations with vegetation type. We then used generalised linear mixed models to relate snake presence and absence to prey (frog abundance), microhabitat (logs and ground cover), wetland hydrology (water depth and inundation frequency) and meteorological conditions, using 12 repeat surveys between September 2018 and March 2021. Key results. Fifty-eight snakes were observed at five of eight wetlands during the study. Ngabi was exclusively recorded in river red gum/spike rush or lignum vegetation communities, and was absent from sandhill woodland or chenopod communities. The probability of detecting Ngabi increased with ambient temperature and weakly with wetland inundation frequency, but not frog abundance, microhabitat attributes or year. Conclusions. Ngabi is strongly associated with floodplain vegetation communities and, to some extent, frequently inundated wetlands in southern NSW, suggesting water management agencies should incorporate threatened floodplain snake species into future wetland management plans. The use of environmental water to restore aspects of flow regimes, improve wetland health and aquatic diversity is likely to benefit other wetland-dependent snake populations across the MDB. Implications. The positive relationship between Ngabi detections and ambient temperature will be important for designing an effective monitoring program for the species across the MDB. Furthermore, our findings provide insight into the benefits of using environmental water to create wetland refuges to maintain floodplain snake populations during droughts.
{"title":"Finding Ngabi (Hemiaspis damelii): factors affecting the use of modified floodplain wetlands by an endangered snake","authors":"D. Michael, D. Nimmo, E. Stevens, T. Schlen, S. Wassens","doi":"10.1071/wr22147","DOIUrl":"https://doi.org/10.1071/wr22147","url":null,"abstract":"ABSTRACT Context. River regulation, coupled with climate change, has caused significant declines in global freshwater biodiversity. In Australia, water extraction within the Murray–Darling Basin (MDB) has reduced the frequency, extent and duration with which floodplains are inundated, resulting in widespread declines in wetland-dependent biodiversity, including reptiles. The endangered Ngabi (Hemiaspis damelii) is associated with floodplain systems in the MDB, yet its distribution and ecological requirements are poorly understood, hampering conservation actions. Aims. We sought to validate an assumption that Ngabi is associated with wetland vegetation communities before investigating factors affecting its probability of detection in the lower Murrumbidgee catchment in southern New South Wales. We predicted Ngabi occurrence patterns would relate to frog abundance, wetland hydrology, microhabitat attributes and meteorological variables. Methods. We compared Ngabi observations from 16 paired wetland and dryland vegetation transects to evaluate associations with vegetation type. We then used generalised linear mixed models to relate snake presence and absence to prey (frog abundance), microhabitat (logs and ground cover), wetland hydrology (water depth and inundation frequency) and meteorological conditions, using 12 repeat surveys between September 2018 and March 2021. Key results. Fifty-eight snakes were observed at five of eight wetlands during the study. Ngabi was exclusively recorded in river red gum/spike rush or lignum vegetation communities, and was absent from sandhill woodland or chenopod communities. The probability of detecting Ngabi increased with ambient temperature and weakly with wetland inundation frequency, but not frog abundance, microhabitat attributes or year. Conclusions. Ngabi is strongly associated with floodplain vegetation communities and, to some extent, frequently inundated wetlands in southern NSW, suggesting water management agencies should incorporate threatened floodplain snake species into future wetland management plans. The use of environmental water to restore aspects of flow regimes, improve wetland health and aquatic diversity is likely to benefit other wetland-dependent snake populations across the MDB. Implications. The positive relationship between Ngabi detections and ambient temperature will be important for designing an effective monitoring program for the species across the MDB. Furthermore, our findings provide insight into the benefits of using environmental water to create wetland refuges to maintain floodplain snake populations during droughts.","PeriodicalId":23971,"journal":{"name":"Wildlife Research","volume":"9 1","pages":"1131 - 1140"},"PeriodicalIF":1.9,"publicationDate":"2023-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81980978","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}
ABSTRACT Context. Bennett’s wallaby (Notamacropus rufogriseus) was introduced into New Zealand in the late-1800s, and has subsequently become a significant pest to agriculture, silviculture, and native vegetation. Effective management of wallabies requires robust spatial and temporal ecological information, which can be used operationally to increase detection and kill rates. Aims. To determine home range size and shape, resource (i.e. habitat and topography) selection, and daily movement patterns of three populations of Bennett’s wallaby in the South Island. Methods. We attached GPS-collars to 38 adult wallabies (17 females, 21 males) between May 2018 and May 2019, and obtained usable location data from 30 individuals. We used kernel density estimators and resource selection functions to quantify seasonal home ranges and resource selection, respectively. Key results. The mean seasonal home range sizes of males and females were similar (26.8 ha and 24.8 ha, respectively; combined range = 1.2–101.9 ha), although the largest home ranges belonged to large males. Resource selection was strongly influenced by distance to concealment cover, ridgelines and streams, i.e. wallabies selected to be closer to these features, though not necessarily at them. Wallabies selected areas close to concealment cover throughout 24-h periods, but most strongly during the day, which is when they bed in dense cover. Wallabies sampled outside of peak breeding moved most during dusk and dawn (median = ~50 m/h), whereas those sampled during peak breeding moved widely during day, dusk, and night (110–280 m/h), but not dawn (median = ~50 m/h). Conclusions. The home range sizes of wallabies in New Zealand were highly variable, but on average were similar for males and females. Wallabies selected pasture close to areas with some cover, suggesting a trade-off between access to high-quality forage and concealment cover. Implications. Our results provide robust data for modelling management strategies for wallabies, and contribute directly to operational planning by identifying habitats where wallabies are most likely to be found temporally. This information can be used to determine the appropriate survey methods and control tools to maximise detection rates and kill rates of wallabies, based on habitat.
{"title":"Spatial ecology of invasive Bennett’s wallaby in South Island, New Zealand","authors":"A. Latham, M. Latham, B. Warburton","doi":"10.1071/wr22127","DOIUrl":"https://doi.org/10.1071/wr22127","url":null,"abstract":"ABSTRACT Context. Bennett’s wallaby (Notamacropus rufogriseus) was introduced into New Zealand in the late-1800s, and has subsequently become a significant pest to agriculture, silviculture, and native vegetation. Effective management of wallabies requires robust spatial and temporal ecological information, which can be used operationally to increase detection and kill rates. Aims. To determine home range size and shape, resource (i.e. habitat and topography) selection, and daily movement patterns of three populations of Bennett’s wallaby in the South Island. Methods. We attached GPS-collars to 38 adult wallabies (17 females, 21 males) between May 2018 and May 2019, and obtained usable location data from 30 individuals. We used kernel density estimators and resource selection functions to quantify seasonal home ranges and resource selection, respectively. Key results. The mean seasonal home range sizes of males and females were similar (26.8 ha and 24.8 ha, respectively; combined range = 1.2–101.9 ha), although the largest home ranges belonged to large males. Resource selection was strongly influenced by distance to concealment cover, ridgelines and streams, i.e. wallabies selected to be closer to these features, though not necessarily at them. Wallabies selected areas close to concealment cover throughout 24-h periods, but most strongly during the day, which is when they bed in dense cover. Wallabies sampled outside of peak breeding moved most during dusk and dawn (median = ~50 m/h), whereas those sampled during peak breeding moved widely during day, dusk, and night (110–280 m/h), but not dawn (median = ~50 m/h). Conclusions. The home range sizes of wallabies in New Zealand were highly variable, but on average were similar for males and females. Wallabies selected pasture close to areas with some cover, suggesting a trade-off between access to high-quality forage and concealment cover. Implications. Our results provide robust data for modelling management strategies for wallabies, and contribute directly to operational planning by identifying habitats where wallabies are most likely to be found temporally. This information can be used to determine the appropriate survey methods and control tools to maximise detection rates and kill rates of wallabies, based on habitat.","PeriodicalId":23971,"journal":{"name":"Wildlife Research","volume":"66 1","pages":"1109 - 1122"},"PeriodicalIF":1.9,"publicationDate":"2023-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75263944","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}
ABSTRACT Context. Wildlife rescue and rehabilitation centres aid millions of species worldwide. The clinical databases from these wildlife rehabilitation centres are increasingly being recognised as valuable scientific resources that have the potential to yield information on animal biology and inform conservation efforts. Although orphaned koala joeys constitute a substantial proportion of wildlife rescues in Australia, the causes of morbidity and mortality, specifically in rescued young koalas, remain largely unexplored. Aims. The primary aim of this study is to analyse the trends in causes and outcomes of koala joeys admitted for rehabilitation at the Adelaide Koala Wildlife Centre (AKWC). Methods. We analysed the hospital records of koala joeys admitted to the AKWC over an 8-year period (2014–2021) to identify the major causes of morbidity and mortality, and analysed the trends in arrivals in terms of season, sex and release rate. Key results. Our examination indicates that the top five major reasons for admission and mortality in koala joeys are as follows – renal disease, heat stress, chlamydiosis, animal attack and vehicle collision. A significant increase in the proportion of heat stress, renal disease and chlamydiosis cases can be observed over the study period. Of the major causes of mortality, the most distinctive feature is the exceptionally high mortality rate of koala joeys with renal disease. Over the study period, the overall positive outcome for all joeys increased up to two-fold, and the mortality rate also declined slightly. Conclusion Despite the significant increase in positive outcome, it is evident that renal disease, chlamydiosis and heat stress are increasing at a rapid rate. Renal disease poses a major threat to rehabilitating koala joeys due to its severely high mortality rate. Implication This is the first study identifying the key drivers of morbidity and mortality of rescued koala joeys, and the rapid increase of renal disease, chlamydiosis and heat stress warrant the attention of future conservation policy developers. Furthermore, the severely high mortality rate of koala joeys due to renal disease warrants improving treatment protocols and any measures that can help reduce the mortality rate of this disease in koala joeys.
{"title":"An 8-year long retrospective analysis identifies the major causes of morbidity and mortality in rescued koala joeys","authors":"H. K. Pahuja, E. Narayan","doi":"10.1071/wr22179","DOIUrl":"https://doi.org/10.1071/wr22179","url":null,"abstract":"ABSTRACT Context. Wildlife rescue and rehabilitation centres aid millions of species worldwide. The clinical databases from these wildlife rehabilitation centres are increasingly being recognised as valuable scientific resources that have the potential to yield information on animal biology and inform conservation efforts. Although orphaned koala joeys constitute a substantial proportion of wildlife rescues in Australia, the causes of morbidity and mortality, specifically in rescued young koalas, remain largely unexplored. Aims. The primary aim of this study is to analyse the trends in causes and outcomes of koala joeys admitted for rehabilitation at the Adelaide Koala Wildlife Centre (AKWC). Methods. We analysed the hospital records of koala joeys admitted to the AKWC over an 8-year period (2014–2021) to identify the major causes of morbidity and mortality, and analysed the trends in arrivals in terms of season, sex and release rate. Key results. Our examination indicates that the top five major reasons for admission and mortality in koala joeys are as follows – renal disease, heat stress, chlamydiosis, animal attack and vehicle collision. A significant increase in the proportion of heat stress, renal disease and chlamydiosis cases can be observed over the study period. Of the major causes of mortality, the most distinctive feature is the exceptionally high mortality rate of koala joeys with renal disease. Over the study period, the overall positive outcome for all joeys increased up to two-fold, and the mortality rate also declined slightly. Conclusion Despite the significant increase in positive outcome, it is evident that renal disease, chlamydiosis and heat stress are increasing at a rapid rate. Renal disease poses a major threat to rehabilitating koala joeys due to its severely high mortality rate. Implication This is the first study identifying the key drivers of morbidity and mortality of rescued koala joeys, and the rapid increase of renal disease, chlamydiosis and heat stress warrant the attention of future conservation policy developers. Furthermore, the severely high mortality rate of koala joeys due to renal disease warrants improving treatment protocols and any measures that can help reduce the mortality rate of this disease in koala joeys.","PeriodicalId":23971,"journal":{"name":"Wildlife Research","volume":"73 1","pages":"1141 - 1153"},"PeriodicalIF":1.9,"publicationDate":"2023-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83290293","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}
Sascha Rösner, Dana G. Schabo, R. Palme, T. Lorenc, Emily Mussard-Forster, R. Brandl, J. Müller
ABSTRACT Context. The assessment of suitable habitat for a species is often evaluated based merely on where the species is most abundant. However, a variety of environmental factors such as temperature, resources and human disturbances might force animals to avoid otherwise high-quality habitats. Additionally, individuals’ capacities to cope with such factors – as reflected in physiological stress responses – may also contribute to avoidance. Combining measures of stress response of individual animals with habitat suitability models may contribute essential insights to the development of species conservation plans. Aims. We used a landscape-level approach to assess whether habitat quality, abiotic factors and human disturbance affect the physiological stress response of a forest specialist, the capercaillie (Tetrao urogallus), and to what extent these relationships are determined by variation between individuals. Methods. We applied a non-invasive approach by collecting 1096 droppings across the entire species range in two adjacent national parks spanning the border between the Czech Republic and Germany. We measured faecal corticosterone metabolites (FCMs) to evaluate the physiological stress response. To test the influences of temperature, habitat quality, season and sex, as well as forest management and tourism intensity on FCM levels, we used generalised additive mixed effect models (GAMMs). The same models were applied for a reduced subset of randomly selected samples that were attributed to individuals via DNA profiling using 10 microsatellite loci. This approach allowed us to control for possible individual differences (through repeated measures within individual genotypes). Key results. Both models revealed decreasing FCM levels with increasing habitat quality and showed no relationship between increasing forestry intensity and FCMs. When accounting for individual identity, we found a significant positive effect from increasing tourism intensity, although this relationship was not significant in the full dataset. Conclusions. Our results highlight three conclusions for the conservation of capercaillie: (1) high-quality habitats reduce stress levels; (2) tourism-free refuge areas are important, and (3) individuality appears to be a strong determinant of response to environmental factors. Implications. Generalising management recommendations from observations for single individuals to an entire population may be inappropriate.
{"title":"High-quality habitats and refuges from tourism reduce individual stress responses in a forest specialist","authors":"Sascha Rösner, Dana G. Schabo, R. Palme, T. Lorenc, Emily Mussard-Forster, R. Brandl, J. Müller","doi":"10.1071/wr21162","DOIUrl":"https://doi.org/10.1071/wr21162","url":null,"abstract":"ABSTRACT Context. The assessment of suitable habitat for a species is often evaluated based merely on where the species is most abundant. However, a variety of environmental factors such as temperature, resources and human disturbances might force animals to avoid otherwise high-quality habitats. Additionally, individuals’ capacities to cope with such factors – as reflected in physiological stress responses – may also contribute to avoidance. Combining measures of stress response of individual animals with habitat suitability models may contribute essential insights to the development of species conservation plans. Aims. We used a landscape-level approach to assess whether habitat quality, abiotic factors and human disturbance affect the physiological stress response of a forest specialist, the capercaillie (Tetrao urogallus), and to what extent these relationships are determined by variation between individuals. Methods. We applied a non-invasive approach by collecting 1096 droppings across the entire species range in two adjacent national parks spanning the border between the Czech Republic and Germany. We measured faecal corticosterone metabolites (FCMs) to evaluate the physiological stress response. To test the influences of temperature, habitat quality, season and sex, as well as forest management and tourism intensity on FCM levels, we used generalised additive mixed effect models (GAMMs). The same models were applied for a reduced subset of randomly selected samples that were attributed to individuals via DNA profiling using 10 microsatellite loci. This approach allowed us to control for possible individual differences (through repeated measures within individual genotypes). Key results. Both models revealed decreasing FCM levels with increasing habitat quality and showed no relationship between increasing forestry intensity and FCMs. When accounting for individual identity, we found a significant positive effect from increasing tourism intensity, although this relationship was not significant in the full dataset. Conclusions. Our results highlight three conclusions for the conservation of capercaillie: (1) high-quality habitats reduce stress levels; (2) tourism-free refuge areas are important, and (3) individuality appears to be a strong determinant of response to environmental factors. Implications. Generalising management recommendations from observations for single individuals to an entire population may be inappropriate.","PeriodicalId":23971,"journal":{"name":"Wildlife Research","volume":"52 1","pages":"1071 - 1084"},"PeriodicalIF":1.9,"publicationDate":"2023-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90082271","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}
Suraj Baral, A. Kunwar, D. Adhikari, Kanti Kandel, Dev Narayan Mandal, A. Thapa, Dinesh Neupane, T. Thapa
ABSTRACT Context. Human-induced changes in climate and land cover have altered the distribution of fauna around the globe. Some reptiles have been found to be vulnerable to these changes; therefore, studies to identify the impact of the changes on other groups of reptiles are necessary. Aims. We aimed to study the impact of climate and land cover change on the yellow monitor (Varanus flavescens) in Nepal. We also aimed to identify the current distribution range and predict the potential distribution under multiple climate change, corresponding land cover change, and dispersion scenarios in the near- and mid-future. Methods. We used available presence locations with a candidate set of the least-correlated environmental variables and an Ensemble of Small Models (ESM), a Species Distribution Model (SDM) approach suitable for species with small sample size. Additionally, dispersal scenarios of 1 km, 5 km, and 10 km were added to the model to determine the future distribution under the dispersal scenarios. Key results. We found soil particle size, distance to forest, precipitation of wettest quarter, bulk density, and elevation were the five most important variables contributing to the distribution of the species. The Terai lowland and wide valleys in Outer Himalayas are currently suitable but are expected to experience a substantial decrease under most future climate projections and dispersal scenarios. Conclusions. The distribution is mostly dependent on soil-related variables; however, climatic variables might have a greater impact on future suitability. Implications. Limiting emissions contributing to climatic changes, conserving the soil outside the protected areas, and the potential areas where the species will not experience habitat loss might contribute to the conservation of the species.
{"title":"The potential distribution of the yellow monitor, Varanus flavescens (Hardwick & Gray) under multiple climate, land cover and dispersal scenarios in Nepal","authors":"Suraj Baral, A. Kunwar, D. Adhikari, Kanti Kandel, Dev Narayan Mandal, A. Thapa, Dinesh Neupane, T. Thapa","doi":"10.1071/wr22176","DOIUrl":"https://doi.org/10.1071/wr22176","url":null,"abstract":"ABSTRACT Context. Human-induced changes in climate and land cover have altered the distribution of fauna around the globe. Some reptiles have been found to be vulnerable to these changes; therefore, studies to identify the impact of the changes on other groups of reptiles are necessary. Aims. We aimed to study the impact of climate and land cover change on the yellow monitor (Varanus flavescens) in Nepal. We also aimed to identify the current distribution range and predict the potential distribution under multiple climate change, corresponding land cover change, and dispersion scenarios in the near- and mid-future. Methods. We used available presence locations with a candidate set of the least-correlated environmental variables and an Ensemble of Small Models (ESM), a Species Distribution Model (SDM) approach suitable for species with small sample size. Additionally, dispersal scenarios of 1 km, 5 km, and 10 km were added to the model to determine the future distribution under the dispersal scenarios. Key results. We found soil particle size, distance to forest, precipitation of wettest quarter, bulk density, and elevation were the five most important variables contributing to the distribution of the species. The Terai lowland and wide valleys in Outer Himalayas are currently suitable but are expected to experience a substantial decrease under most future climate projections and dispersal scenarios. Conclusions. The distribution is mostly dependent on soil-related variables; however, climatic variables might have a greater impact on future suitability. Implications. Limiting emissions contributing to climatic changes, conserving the soil outside the protected areas, and the potential areas where the species will not experience habitat loss might contribute to the conservation of the species.","PeriodicalId":23971,"journal":{"name":"Wildlife Research","volume":"9 1","pages":"1097 - 1108"},"PeriodicalIF":1.9,"publicationDate":"2023-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79042609","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}
Naomi L. Indigo, Ella Kelly, James Smith, J. Webb, Ben L. Phillips
ABSTRACT Context. Animals can be taught new behaviours to mitigate threatening processes. However, it is yet to be confirmed if such teaching can be deployed in the field. Here we test this possibility using the invasion of cane toads because they are highly toxic novel prey items to many predators across northern Australia. Aims. Research has shown that training predators to avoid toads, using conditioned taste aversion (CTA), significantly improves the survival rates of individuals. We sought to determine if deployment of CTA baits, in situ, could reduce cane toad impacts on a mammalian predator, the northern quoll (Dasyurus hallucatus). Methods. The work was conducted in the Kimberley, Western Australia, where we treated three quoll populations with training baits from November 2015–November 2017, and kept four populations as controls. We used camera traps and Bayesian hierarchal modelling to estimate the population size of quolls on up to four occasions before, and two occasions after, cane toad arrival. Key results. We observed a 65% reduction in quoll population size at control sites and a 94% reduction at treatment sites: a significant effect of aversion training, but in the direction opposite to that expected. Conclusions. Two complexities – decay of aversion, and individual variation – together, may explain our result. Our trials indicate that most animals are no longer averse within 120 days post-training. Earlier studies indicating that aversion training lasts longer may have inadvertently observed innate (i.e. genetically based) aversion to cane toads. Another possibility is that our dose rate of thiabendazole within the CTA baits was, in fact, too low; or the result may be an artefact of the non-random assignment of treatment and control groups. Ultimately, there is no way of determining exactly why our outcome occurred without further laboratory/captive trails. Regardless, our study demonstrates a failure of CTA training to mitigate the impact of cane toads on northern quolls in this system. Implications. Our result calls into question the value of this approach for conserving quoll populations, at least in its current form. More generally, our results point to the often-unexpected complexities encountered as ideas progress from captive trials to field deployment.
{"title":"Can conditioned taste aversion be deployed at a landscape level to mitigate the impact of invasive cane toads on northern quolls?","authors":"Naomi L. Indigo, Ella Kelly, James Smith, J. Webb, Ben L. Phillips","doi":"10.1071/wr21151","DOIUrl":"https://doi.org/10.1071/wr21151","url":null,"abstract":"ABSTRACT Context. Animals can be taught new behaviours to mitigate threatening processes. However, it is yet to be confirmed if such teaching can be deployed in the field. Here we test this possibility using the invasion of cane toads because they are highly toxic novel prey items to many predators across northern Australia. Aims. Research has shown that training predators to avoid toads, using conditioned taste aversion (CTA), significantly improves the survival rates of individuals. We sought to determine if deployment of CTA baits, in situ, could reduce cane toad impacts on a mammalian predator, the northern quoll (Dasyurus hallucatus). Methods. The work was conducted in the Kimberley, Western Australia, where we treated three quoll populations with training baits from November 2015–November 2017, and kept four populations as controls. We used camera traps and Bayesian hierarchal modelling to estimate the population size of quolls on up to four occasions before, and two occasions after, cane toad arrival. Key results. We observed a 65% reduction in quoll population size at control sites and a 94% reduction at treatment sites: a significant effect of aversion training, but in the direction opposite to that expected. Conclusions. Two complexities – decay of aversion, and individual variation – together, may explain our result. Our trials indicate that most animals are no longer averse within 120 days post-training. Earlier studies indicating that aversion training lasts longer may have inadvertently observed innate (i.e. genetically based) aversion to cane toads. Another possibility is that our dose rate of thiabendazole within the CTA baits was, in fact, too low; or the result may be an artefact of the non-random assignment of treatment and control groups. Ultimately, there is no way of determining exactly why our outcome occurred without further laboratory/captive trails. Regardless, our study demonstrates a failure of CTA training to mitigate the impact of cane toads on northern quolls in this system. Implications. Our result calls into question the value of this approach for conserving quoll populations, at least in its current form. More generally, our results point to the often-unexpected complexities encountered as ideas progress from captive trials to field deployment.","PeriodicalId":23971,"journal":{"name":"Wildlife Research","volume":"14 1","pages":"1046 - 1057"},"PeriodicalIF":1.9,"publicationDate":"2023-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75119252","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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