4. Conclusions and Recommendations
The wildlife−domestic interface defines if and how infectious diseases
will spread between wildlife and domestic populations. Understanding of
this interface involves detailed field studies on the context and nature
of interactions between populations. Such knowledge can be incorporated
into disease spread models to understand how diseases might behave at
the wildlife−domestic interface. Specifically, quantitative estimation
of contact rates permits such disease spread models to be developed and
used confidently.
Over a period of 10 years, free-roaming domestic dogs and wild dogs in
the Northern Peninsula Area (NPA) were studied with the objective of
understanding the potential consequences of an incursion of rabies in
this area, and more broadly in northern Australia. Key epidemiological
findings included identification of a small but important group of
domestic dogs which regularly roam in bushland areas; peri-urban wild
dog activity, particularly in the dry season, likely driven by the
availability of food sources; and the potential for interaction between
hunting dogs and wild dogs in remote areas, particularly during the wet
season. Such disease spread pathways must be incorporated into models to
realistically represent the potential outcomes of a disease incursion
within this ecosystem. Furthermore, these studies have generated
quantitative information on home ranges, utilisation distributions, and
the overlap in activity of domestic and wild dogs. This information can
be used to infer contacts between these two populations and thus model
disease spread at the wild−domestic interface.
The roaming behaviour of domestic dogs in northern Australian Indigenous
communities is a recognised feature of these communities, and this
characteristic is determined by cultural norms as well as structural
disadvantage (Brookes et al., 2020; Degeling et al., 2018). Studies on
the roaming behaviour of domestic dogs are therefore important as input
to disease spread models. Recognition of the heterogeneity in roaming
behaviour in these populations presents an opportunity to control
disease spread at the wild−domestic interface (Hudson et al., 2016).
Strategies to mitigate transmission could focus on restricting movement
of domestic dogs to limit potential interactions with wild dogs during
risk periods (Ward et al., 2021). However, whether the behavioural
characteristic of exploring is specific to certain dogs, and methods to
reliably identify “explorer” dogs, are research questions which need
to be resolved via low-term monitoring of these populations.
Another strategy would be to reduce the activity of wild dogs around
communities. This could be done by restricting access to food sources –
for example better fencing of waste disposal sites (Ward et al., 2021).
This would have maximum benefit during the dry season. Ongoing
monitoring of such sites would generate information on which wild dogs
are part of this interface, the relationship between dog activity and
resource availability, and whether breeding season is a driver of these
contacts, with implications for potential disease spread. This requires
more than ad hoc research studies. In addition, studies that
employ genetic analysis can provide useful information to develop an
understanding of the wild−domestic interface (Bombara et al., 2017a;
Gabriele-Rivet et al., 2021c).
Whilst hunting might contribute to the wild−domestic interface,
characterising and measuring contacts is problematic. Hunting trips
often occur during nocturnal hours, and hunting dogs travel out of sight
during hunting activities (Gabriel-Rivet et al., 2019a; Sparkes et al.,
2016). Hunters can also sometimes lose their dogs. Therefore, contacts
between hunting and wild dogs are difficult to observe, record and
measure. To contribute to more realistic disease spread models, more
field research is needed to estimate contact rates, and identify when,
where and under what circumstances these occur as a result of hunting.
For example, roads within otherwise densely vegetated areas might act as
potential contact hotspots (Gabriele-Rivet et al., 2021b; Vernes et al.,
2001). Additional field methods and study designs are needed to
understand such characteristics of the wild−domestic interface.
Disease spread models are valuable to help us understand the
wildlife−domestic interface. However, to produce insights that can be
used to mitigate the effects of disease spread such models require
parameterisation of effective contact, which is defined using
fundamental knowledge of the underlying system and field data. We have
summarised a decade of research conducted to understand one such
interface, the wild−domestic dog interface at one site in northern
Australia, for the purposes of exploring the impact of one specific
disease, rabies. Further development of disease spread models that focus
on this interface is the catalyst needed to generate field data to
inform these models and provide a deeper understanding of the
wildlife−domestic interface.