African swine fever effects on the northernmost Amur tiger (Panthera tigris altaica) subpopulation

The wild boar (Sus scrofa) population in the southern Russian Far East declined by 90-95% because of an African swine fever (ASF) epizootic that began in 2019. The loss of this primary prey species for Amur tigers (Panthera tigris altaica), at a time when other main prey species were low in abundance and intensive habitat degradation and poaching were occurring, could affect population dynamics of tigers at the northern edge of their range. We assessed the impact of the ASF epizootic on the northernmost Amur tiger subpopulation by comparing population parameters before and after the ASF event. We assessed the number, types, and spatial distribution of conflicts between tigers and humans, timing of births, cub survival rates, tiger physical condition, behavior, and mortality. The average annual number of human–tiger conflicts increased more than 11-fold after the arrival of ASF, with attacks on domestic animals being the predominant conflict. Tiger mortality and human-mediated removal of tigers due to conflicts increased 3.3-fold after ASF, and the total area in which conflicts occurred also increased. There was an increase in the proportion of emaciated individuals within the tiger population, particularly among young animals and males, and the proportion of individuals that preyed upon domestic animals also increased, a behavioral shift that expanded food resources for tigers but also heightened risks for both tigers and humans. To mitigate effects of the ASF outbreak and support the recovery of this Amur tiger population, we recommend a temporary ban on hunting of their primary prey species, additional protections for the wildlife sanctuaries within their range, and a large-scale population survey.