Cassandra M. Arkinstall, Sean I. FitzGibbon, Kevin J. Bradley, Katherine E. Moseby, Peter J. Murray
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引用次数: 0
Abstract
Context
The distribution of the threatened greater bilby (Macrotis lagotis) has significantly contracted since the introduction of feral cats and foxes. To counteract these threats, bilbies have been reintroduced to multiple feral predator exclosures and offshore islands across Australia.
Aims
The aims of this study were to monitor the reintroduction of bilbies to the feral predator exclosure at Currawinya National Park and assess three hypotheses: (1) captive-born founders would establish stable home ranges and utilise habitats similar to those of wild-born bilbies in the exclosure; (2) founders would maintain adequate body condition and weight, enabling the survival of >50% of founders at 12 months post-release; and (3) the population would rapidly increase in the absence of feral predators, due to the high reproductive potential of bilbies.
Methods
We used VHF/GPS telemetry to compare home range size and habitat use of 12 founders and 11 wild-born bilbies. Founders were monitored intensively to assess reproductive success, weight, body condition and survival. Pouch activity was monitored to examine reproductive output. Spatially explicit capture–recapture modelling was used to estimate population density/size.
Key results
The population rapidly increased to >450 bilbies after 3 years, and founder survivorship was high (70% at 12 months post-release). Male founder home ranges (248.46 ha ± 97.22) were comparable in size to wild-born males (216.74 ha ± 54.19), but female founder home ranges (51.23 ha ± 12.22) were significantly larger than wild-born females (20.80 ha ± 2.94) (P = 0.04). The doubling of the population between 2021 and 2022 may have resulted in the contraction of female home ranges. Reproductive output decreased significantly in 2022, indicating that reproduction may be density-dependent at high densities. There was a significant relationship between track counts and population estimates, indicating that track counts are a reliable method for estimating population size inside the exclosure.
Conclusions
This reintroduction has been highly successful to date, demonstrating that bilbies are an adaptable species capable of rapid population growth in the absence of feral predators.
Implications
Bilbies are a model species for reintroductions to feral predator exclosures due to high survival rates, reproductive output, dietary flexibility and the ability to utilise a broad range of environments.
期刊介绍：
Wildlife Research represents an international forum for the publication of research and debate on the ecology, management and conservation of wild animals in natural and modified habitats. The journal combines basic research in wildlife ecology with advances in science-based management practice. Subject areas include: applied ecology; conservation biology; ecosystem management; management of over-abundant, pest and invasive species; global change and wildlife management; diseases and their impacts on wildlife populations; human dimensions of management and conservation; assessing management outcomes; and the implications of wildlife research for policy development. Readers can expect a range of papers covering well-structured field studies, manipulative experiments, and analytical and modelling studies. All articles aim to improve the practice of wildlife management and contribute conceptual advances to our knowledge and understanding of wildlife ecology.
Wildlife Research is a vital resource for wildlife scientists, students and managers, applied ecologists, conservation biologists, environmental consultants and NGOs and government policy advisors.
Wildlife Research is published with the endorsement of the Commonwealth Scientific and Industrial Research Organisation (CSIRO) and the Australian Academy of Science.
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