Suchergebnisse

Context In Nepal, naur are usually the staple wild prey for the snow leopard, a solitary stalker hunter, and in some cases, for the wolf who hunts in a pack. We assumed that naur would adapt their anti-predatory responses to the presence of chasing and ambushing predators in the Manang Valley, where there are snow leopards and wolves, and in the Nar Phu valley, an area where there is only the snow leopard. Aims The aim of this study was to determine if there were differences in anti-predator strategies (vigilance, habitat selection and escape terrain) of naur in two valleys over two seasons, spring and autumn. Methods In spring 2019, we conducted a reconnaissance survey on the status of the naur and its habitat in the Manang and Nar Phu valleys of the Annapurna Conservation Area, Nepal. In spring and autumn 2020 and 2021, we observed 360 focal naur individuals (180 individuals in each valley), using the vigilance behaviour methodology to examine the behaviour of the naur. Key results There was little difference in the size of the naur groups between the Manang and Nar Phu valleys. The naur were twice as vigilant in Manang (15%), where there are snow leopards and wolves, as they were in Nar Phu (9%), with only snow leopards. The distance from the naur to escape cover was significantly shorter in Manang than in Nar Phu valley. Naur used significantly more rolling terrain in Nar Phu than in Manang. Conclusions The return of wolves to the Manang valley may have resulted in an increase in the level of naur vigilance. Most likely, the wolves in Manang have already had an effect on the female-to-young-ratio, and this effect will possibly have important consequences for the naur population, as well as at the ecosystem level in the future. Other key determining factors, such as the climate crisis and changes in local resources, could have a significant impact on the naur population, indicating the need for more research. Implications The findings of this study would provide valuable baseline information for the design of a science-based conservation strategy for conservation managers and scientists on naur, snow leopards and wolves.

Context Small mammals may traverse the urban fringe and use both natural and anthropogenic resources. In Australia, human commensal black rats (Rattus rattus) and native long-nosed bandicoots (Perameles nasuta) are important tick hosts, which can be found persisting at the urban fringe, leading to human–wildlife conflict. Aims We aimed to (1) determine the relative activity of small mammals in yards and associations with yard attributes, (2) compare activity of black rats and long-nosed bandicoots in bushland with activity in yards and (3) determine the proportion of black rats and long-nosed bandicoots that crossed the urban fringe. We predicted that native bandicoots would be more active in bushland habitats and that black rats would be more active in yards. Methods We used camera trapping in 56 residential yards, 18 of which were paired with adjacent bushland to measure small mammal activity in the two habitats. We recorded yard attributes and examined these associations using generalised linear models. We used isodar analysis to investigate black rat preferences of bushland habitat compared with yards, and we used Rhodamine B baiting to investigate movement at the urban fringe. Key results We found that black rats were the most active small mammal in residential yards and were detected in more yards than other small mammals, followed by bandicoots. Black rat activity was greater in yards adjacent to bushland, but no other yard attributes were associated with black rat and bandicoot activity. Overall, activity tended to be higher in bushland than in yards at paired locations. Conclusions Our findings suggest residential yards likely provide high-quality resources for long-nosed bandicoots. Low rates of movement at the urban fringe (6%), and a preference for bushland at low densities suggests that black rats may be synanthropic rather than commensal, occupying an urban niche but not depending on anthropogenic resources as expected. Implications Residential properties located adjacent to bushland may be exposed to increased black rat activity in yards. Future work should consider how introduced rats may be controlled in bushland to assist urban rat control efforts and avoid non-target impacts. Residential yards are likely to be important habitat for the persistence of long-nosed bandicoots in urban environments.

AbstractWith urban encroachment on wild landscapes accelerating globally, there is an urgent need to understand how wildlife is adapting to anthropogenic change. We compared the behaviour of the invasive red fox (Vulpes vulpes) at eight urban and eight peri-urban areas of Sydney, Australia. We observed fox behaviour around a lure and compared fox activity patterns to those of potential prey and to two domestic predators (dogs—Canis lupus familiaris and cats—Felis catus). We assessed the influence of site type, vegetation cover, and distance from habitation on fox behaviour, and compared the temporal activity patterns of urban and peri-urban red foxes. Urban red foxes were marginally more nocturnal than those in peri-urban areas (88% activity overlap). There was greater overlap of red fox activity patterns with introduced mammalian prey in urban areas compared with peri-urban areas (90% urban vs 84% peri-urban). Red fox temporal activity overlapped 78% with cats, but only 20% with dogs, across both site types. The high degree of overlap with cats and introduced mammalian prey is most likely explained by the nocturnal behaviour of these species, while pet dogs are generally kept in yards or indoors at night. The behavioural differences we documented by urban red foxes suggest they may adapt to human modifications and presence, by being more nocturnal and/or more confident in urban areas.

Context In the vicinity of the western Rajaji Tiger Reserve, a significant rise in conflicts between humans and leopards has occurred. These conflicts have resulted in a substantial number of human deaths, with 60% attacks resulting in deaths over a 4-year period. Aims This study aims to examine any potential connection among the non-breeding tigers, leopards, prey, humans and the increased occurrence of conflicts. Methods To address this objective, we conducted an analysis to evaluate the density of leopards, as well as their spatial and temporal behaviour with respect to tigers, prey and humans through on-site habitat use, circular statistics, diel-overlap as well spatial niche breadth and spatial-niche overlap. Key results Our findings showed one of the highest leopard-density estimates (excluding cubs) (mean ± s.e.) of 23.7 ± 4.8 per 100 km2. When examining on-site habitat use by leopards, we found three variables that had a negative influence, namely, human presence, slope, and the presence of tigers. The presence of a large prey (sambar) had a positive influence. Leopards, exhibiting the highest spatial-niche breadth, demonstrated a small overlap with both tigers and humans, while displaying a significant diel overlap with sambar. The niche overlap was notably high with sambar, but very low with humans and tigers. Conclusions Although tigers locally created a zone of spatial and temporal avoidance, at the population level the leopards experienced a surge in numbers in response to the reduced tiger numbers, indicated by their high density. This could be a cause of high leopard movement into nearby human settlements. This unique scenario could have contributed to conflict. Implications Understanding the coexistence among different species and the impact of transient animals is crucial to develop effective management strategies to mitigate conflict. This approach would facilitate and ensure the long-term survival of diverse large carnivores in the tropical forests of southern Asia through sustained support for conservation from local communities.

Context Freshwater ecosystems rank among the most threatened environments on Earth. Monitoring aquatic and semi-aquatic species is vital to informing conservation of freshwater ecosystems. However, many semi-aquatic mammals can be difficult to detect with conventional survey methods. Aims We aimed to identify the most effective survey method for detecting an Australian semi-aquatic mammal, the rakali (Hydromys chrysogaster). Methods We compared rakali detection rates among camera-trapping, live-trapping and visual surveys, and tested the influence of camera angle, trap proximity to water and time of survey, across the Yanco Creek system in southern New South Wales. Key results Nocturnal spotlight surveys were the most effective method for detecting rakali, with most observations occurring while individuals were foraging or swimming in the water. Camera traps facing a floating platform and cage traps mounted on floating platforms performed better than those deployed on land. Downward-facing camera traps detected rakali three times more often than did forward-facing cameras. Trapping rakali was unreliable, with the species detected at fewer than half of the sites where presence was confirmed via visual observation and camera traps. For species absence to be determined with 95% confidence, 2–4 weeks of nightly trapping is required, compared with six nights of visual surveys or 12 nights for a platform-facing camera. Morning visual surveys were largely ineffective because of predominantly nocturnal rakali activity and difficulty in detecting signs in creek environments. Conclusions The likelihood of detecting rakali can be maximised through the use of nightly spotlighting and deployment of baited camera traps focussed on platforms or natural resting areas within a water body. Implications Understanding the effectiveness of each method is essential for developing species-appropriate protocols for population monitoring. Our findings present suitable options to be further explored among the 100-plus small (<1 kg) semi-aquatic mammals worldwide that share similar behaviours and characteristics to the rakali, many of which are threatened or data deficient.

Context Quantifying marine turtle-nest depredation by daily observer monitoring requires substantial labour. Aims To quantify nest depredation of the Vulnerable flatback turtle (Natator depressus) at one of its largest rookeries and to compare effectiveness of different monitoring methods. Methods We used daily observer monitoring and passive infrared-camera traps separately or in combination to record nest depredation, and identified impacts on remaining eggs and hatchlings in depredated nests. Key results More than a quarter (28%) of the 69 monitored nests were confirmed as depredated, although this figure is an underestimate of total losses because camera traps detected twice as many depredation events (39%) as did direct observation (17%) (P = 0.012). Cameras also provided important behavioural data and identified predators. Although reptile and bird predators were also recorded, the introduced red fox (Vulpes vulpes) was the primary predator identified, digging into 26% of the monitored nests. More than half of the depredation events by foxes (58% or 11/19 nests) occurred late term, between turtles hatching and emerging from the nest, which therefore means that losses calculated through counts of eggshell left in the nest are underestimates because predation of hatchlings is not included by the eggshell count method. Furthermore, almost half (42%) of all depredated nests were depredated more than once, with some nests opened up to five times, potentially exacerbating clutch losses due to environmental exposure. Conclusions Egg losses for confirmed depredated nests (27 ± 37%, range 0–100%) were three times the background levels (i.e. 9.3% of eggs that failed to hatch as a result of embryo death during development). Implications The results of this study strongly warrant the implementation of ongoing fox predator monitoring and mitigation strategies to protect nests at this nationally, and internationally, conservation-significant population of flatback turtles.

Context A comprehensive understanding of movements and space use can underpin the effective management of threatened species. GPS dataloggers can collect large amounts of high-quality movement data, and recent advances in statistical approaches allow for robust estimates of home range size to be generated. Until recently, technological and practical constraints have generally restricted the collection of movement data via GPS dataloggers to larger species. However, reductions in the size and weight of GPS dataloggers now allow for this technology to be applied to smaller species. Aims The aim of this study was to describe the home range and movement patterns of a nationally vulnerable, native Australian ground-dwelling mammal, the long-nosed potoroo (Potorous tridactylus), in south-west Victoria, mainland Australia. Methods We attached GPS dataloggers to 40 long-nosed potoroos between 2020 and 2022 and estimated home range size using dynamic Brownian Bridge movement models. We evaluated the influence of physiological factors such as body mass and sex on home range size and described patterns of home range overlap between and within sexes. Key results Mean home range sizes were estimated to be 13.73 ha (95% CI: 10.9–16.6) and 6.67 ha (95% CI: 5.49–7.85) for males and females respectively. Home range size scaled with body mass in males but not females, and ranges were largely overlapping – although there was some evidence of intrasexual spatial partitioning of core range areas in females. Conclusions Ours is the first application of GPS dataloggers to this species, and our home range estimates are over twice as large as other reported estimates for mainland Australia. Long-nosed potoroos may range across larger areas than previously predicted on mainland Australia. Implications This knowledge may be used to optimise the management of long-nosed potoroo populations before and after fire – a key threatening process for this species. Our study highlights the value of integrating GPS dataloggers and robust home range estimators when describing the movement ecology of a population.

Abstract Context It is widely recognised that red foxes (Vulpes vulpes) are abundant within urban areas; however, it is difficult to apply lethal control measures using poison baits in cities because of concerns about the safety of domestic pets, particularly dogs (Canis familiaris). Aims We tested canid pest ejectors (CPEs) as a potential method of fox control by measuring visitation and activation behaviour of foxes and other wildlife while assessing non-target risk to domestic dogs. Methods We compared eight urban and eight peri-urban sites in Sydney, with half of the sites having restricted access for domestic dogs. We allocated five camera traps and ejectors per site. Through generalised linear mixed models, we compared the probability of ejector activation between foxes and dogs. We also assessed the relationship between dog visitation and distance to habitation and dog restrictions as measures of dog safety. Key results Both species of canids were equally likely to pull the ejector (P = 0.26). As expected, dog visitation was significantly lower in sites with dog restrictions (P < 0.001). However, it was not related to distance from habitation. Only two non-canid species were recorded pulling the ejector, suggesting high target-specificity for canids. Conclusions In sites with dog restrictions, the risk of dog casualties from CPEs is minimal. However, distance from habitation does not increase dog safety, at least within 250 m. The ejector is highly specific for canids. Implications We provide specific recommendations for the design of a potential fox control program using CPEs in urban and peri-urban areas. The ejector may be a safe method for fox control in cities when deployed at places without domestic dogs.

Synthesizing trait observations and knowledge across the Tree of Life remains a grand challenge for biodiversity science. Species traits are widely used in ecological and evolutionary science, and new data and methods have proliferated rapidly. Yet accessing and integrating disparate data sources remains a considerable challenge, slowing progress toward a global synthesis to integrate trait data across organisms. Trait science needs a vision for achieving global integration across all organisms. Here, we outline how the adoption of key Open Science principles—open data, open source and open methods—is transforming trait science, increasing transparency, democratizing access and accelerating global synthesis. To enhance widespread adoption of these principles, we introduce the Open Traits Network (OTN), a global, decentralized community welcoming all researchers and institutions pursuing the collaborative goal of standardizing and integrating trait data across organisms. We demonstrate how adherence to Open Science principles is key to the OTN community and outline five activities that can accelerate the synthesis of trait data across the Tree of Life, thereby facilitating rapid advances to address scientific inquiries and environmental issues. Lessons learned along the path to a global synthesis of trait data will provide a framework for addressing similarly complex data science and informatics challenges.

Synthesizing trait observations and knowledge across the Tree of Life remains a grand challenge for biodiversity science. Species traits are widely used in ecological and evolutionary science, and new data and methods have proliferated rapidly. Yet accessing and integrating disparate data sources remains a considerable challenge, slowing progress toward a global synthesis to integrate trait data across organisms. Trait science needs a vision for achieving global integration across all organisms. Here, we outline how the adoption of key Open Science principles-open data, open source and open methods-is transforming trait science, increasing transparency, democratizing access and accelerating global synthesis. To enhance widespread adoption of these principles, we introduce the Open Traits Network (OTN), a global, decentralized community welcoming all researchers and institutions pursuing the collaborative goal of standardizing and integrating trait data across organisms. We demonstrate how adherence to Open Science principles is key to the OTN community and outline five activities that can accelerate the synthesis of trait data across the Tree of Life, thereby facilitating rapid advances to address scientific inquiries and environmental issues. Lessons learned along the path to a global synthesis of trait data will provide a framework for addressing similarly complex data science and informatics challenges.

Synthesizing trait observations and knowledge across the Tree of Life remains a grand challenge for biodiversity science. Species traits are widely used in ecological and evolutionary science, and new data and methods have proliferated rapidly. Yet accessing and integrating disparate data sources remains a considerable challenge, slowing progress toward a global synthesis to integrate trait data across organisms. Trait science needs a vision for achieving global integration across all organisms. Here, we outline how the adoption of key Open Science principles—open data, open source and open methods—is transforming trait science, increasing transparency, democratizing access and accelerating global synthesis. To enhance widespread adoption of these principles, we introduce the Open Traits Network (OTN), a global, decentralized community welcoming all researchers and institutions pursuing the collaborative goal of standardizing and integrating trait data across organisms. We demonstrate how adherence to Open Science principles is key to the OTN community and outline five activities that can accelerate the synthesis of trait data across the Tree of Life, thereby facilitating rapid advances to address scientific inquiries and environmental issues. Lessons learned along the path to a global synthesis of trait data will provide a framework for addressing similarly complex data science and informatics challenges.