3.3. Contact structure: wild dogs
Wild dogs in Australia might act as a reservoir of rabies if an
incursion of this exotic disease occurred. The presence of a wildlife
reservoir would make rabies eradication difficult and have far reaching
economic and social implications (Sparkes et al., 2015).
Existing data to inform rabies spread modelling in wild dog populations
are scarce. In a scoping review of wild-living dog ecology and biology
in Australia to inform parameterisation for disease spread
(Gabriele-Rivet et al., 2019b), lack of data on density and contacts are
major research gaps in the literature: only a small number of recent
studies on these topics (14 and 12, respectively) was found, with few
quantitative estimates. Even for home range, only 24 studies were
identified that provided usable evidence. Information from equatorial
and tropical climate zones of northern Australia – a high-risk area for
a rabies incursion – to inform disease spread is even more limited.
Within these zones, no studies reporting information on contact rates
were found, and only one study reporting wild dog home range was
identified.
In the case of wild dogs, measuring home ranges and inferring contact
rates is challenging, particularly in the context of the equatorial and
tropical climate zones of northern Australia. Gabriele-Rivet et al
(2020) used a camera trap survey to monitor the wild dog population in
the NPA. Wild dog density and home range size estimates were derived via
maximum-likelihood, spatially explicit, mark–resight models. Densities
varied from 0.135 animals/km2 (95% CI = 0.127–0.144)
during the dry season to 0.147 animals/km2 (95% CI =
0.135–0.159) during the wet season. Although densities were relatively
uniform during the year, suggesting a stable population, estimated home
range sizes were highly variable (7.95–29.40 km2). Of
note, these home ranges are comparable to some of the estimated HRs of
roaming domestic dogs in the NPA (Dürr and Ward, 2014; Hudson et al.,
2017; Bombara et al., 2017a).