Dingo Density Estimates and Movements in Equatorial Australia: Spatially Explicit Mark–Resight Models

SIMPLE SUMMARY: Australia is historically canine rabies-free but faces the threat of a rabies incursion due to the current spread of rabies through eastern Indonesia. To address this genuine concern, it is necessary to acquire further ecological knowledge on dingo populations in northern Australia to improve our predictions on the potential spread of rabies within dingoes, should an incursion occur. A one-year camera trap study was conducted in northern Australia, where the risk of the introduction of rabies is highest. Our resulting estimates of population density and home range sizes of dingoes in the study area varied according to seasons. Additionally, based on an analysis of spatial use and daily activity patterns from the camera trap pictures, a large spatial correlation and temporal overlap between dingoes and free-roaming community dogs was observed, suggesting a potential risk of disease transmission at the wild–domestic interface. This information will help improve preparedness planning for a rabies incursion in Australia. ABSTRACT: Australia is currently free of canine rabies. Spatio-ecological knowledge about dingoes in northern Australia is currently a gap that impedes the application of disease spread models and our understanding of the potential transmission of rabies, in the event of an incursion. We therefore conducted a one-year camera trap survey to monitor a dingo population in equatorial northern Australia. The population is contiguous with remote Indigenous communities containing free-roaming dogs, which potentially interact with dingoes. Based on the camera trap data, we derived dingo density and home range size estimates using maximum-likelihood, spatially explicit, mark–resight models, described dingo movements and evaluated spatial correlation and temporal overlap in activities between dingoes and community dogs. Dingo density estimates varied from 0.135 animals/km(2) (95% CI = 0.127–0.144) during the dry season to 0.147 animals/km(2) (95% CI = 0.135–0.159) during the wet season. The 95% bivariate Normal home range sizes were highly variable throughout the year (7.95–29.40 km(2)). Spatial use and daily activity patterns of dingoes and free-roaming community dogs, grouped over ~3 month periods, showed substantial temporal activity overlap and spatial correlation, highlighting the potential risk of disease transmission at the wild–domestic interface in an area of biosecurity risk in equatorial northern Australia. Our results have utility for improving preparedness against a potential rabies incursion.