3.6. Summary of findings
Insights from this case study suggest that interactions between domestic dogs and dingoes, and hence risk for disease transmission at the wild−domestic interface, are more likely to occur around the communities during the dry season, whereas the risk seems to be increased in bush areas away from the communities during the wet season. The former is likely driven by the availability of freely accessible food sources which attracts wild dogs and the presence of roaming domestic dogs, and the latter is apparently driven by an intensification of hunting activities with domestic dogs coupled with a higher level of wild dog activity in these same areas. These two potential disease pathways need to be incorporated into any model of disease spread within this ecosystem.
Monitoring of roaming domestic dogs at the study site demonstrates that most dogs will “stay at home” and only explore their immediate surroundings. However, there is a proportion of the population (estimated to be 29% by Hudson et al. (2017)) which will explore their surroundings, including areas of bushland where contact with wild dogs is possible. Dog factors such as age, sex, and neuter status do not appear to be strong predictors of this roaming behaviour. However, recognition of the heterogeneity of roaming behaviour in populations of roaming dogs in Indigenous communities presents an opportunity to reduce disease spread at the wild−domestic interface (Hudson et al., 2016).
Wild dogs often reside near human settlements (Allen et al. 2013; Sparkes et al. 2016) and their home range can be configured around supplementary food sources, such as mine sites and refuse facilities (Allen et al. 2013; Newsome et al. 2013; McNeill et al., 2016). It is likely that sites are more frequented when wild dogs have unrestricted access to resources such as food, water and vegetation coverage (Sparkes et al. 2015). Therefore, locations such as waste disposal sites pose a risk because higher wild dog activity around human-provided resources could increase contact opportunities with free-roaming domestic-type dogs (Fleming et al. 2001; Newsome et al. 2013; Bombara et al. 2017b; Hudson et al., 2016; Hudson et al., 2017), and provide opportunity for disease transmission between the two dog populations. The findings of hybridisation studies also support the existence of this wild−domestic interface (Bombara et al., 2017a; Gabriel-Rivet et al., 2021c). In addition, greater activity in wild dog populations between dusk and dawn have been observed, due to aversion to human activity and more profitable foraging opportunities following dusk (Allen et al.2013; Newsome et al. 2013; Ward et al., 2021). Thus contacts are more likely during these times of the day. The presence of community-associated food resources which attract wild dogs – particularly during the dry season − need to be incorporated into disease spread models. Monitoring of these sites to estimate contact rates is a priority for such research.
The role that hunting might play at the study site, and more broadly across northern Australia, needs more investigation. During hunting trips, dogs can travel in the bush for long distances (up to 4 km) and for a considerable amount of time (up to 9 h), whilst being remotely monitored by hunters using GPS technology. This hunting behaviour can increase the chances of encountering wild dogs (Gabriel-Rivet et al., 2019a). Studies in the NPA (Gabriel-Rivet et al., 2021b) indicate that opportunities for encounters are likely, which is consistent with the results of a previous survey of Australian hunters (Sparkes et al., 2016), in which 50% of the hunters interviewed witnessed at least one encounter with wild dogs throughout their hunting experience. However, the probability or rate of effective contact needs quantification for the purpose of disease spread modelling to determine the relative risk posed by this interface compared to others such as the wild−domestic peri-community interface.