Impact of infectious diseases on wild bovidae populations in Thailand: Insights from population modelling and disease dynamics

The wildlife and livestock interface is vital for wildlife conservation
and habitat management. Infectious diseases maintained by domestic species
may impact threatened species such as Asian bovids, as they share natural
resources and habitats. To predict the population impact of infectious
diseases with different traits, we used stochastic mathematical models to
simulate the population dynamics over 100 years for 100 times a model gaur
(Bos gaurus) population with and without disease. We simulated repeated
introductions from a reservoir, such as domestic cattle. We selected six
bovine infectious diseases; anthrax, bovine tuberculosis, hemorrhagic
septicaemia, lumpy skin disease, foot and mouth disease and brucellosis,
all of which have caused outbreaks in wildlife populations. From a
starting population of 300, the disease-free population increased by an
average of 228% over 100 years. Brucellosis with frequency-dependent
transmission showed the highest average population declines (-97%), with
population extinction occurring 16% of the time. Foot and mouth disease
with frequency-dependent transmission showed the lowest impact, with an
average population increase of 200%. Overall, acute infections with very
high or low fatality had the lowest impact, whereas chronic infections
produced the greatest population decline. These results may help disease
management and surveillance strategies support wildlife conservation.