Mortality factors of the Ussuri sika deer Cervus nippon hortulorum Swinhoe, 1864 in the Lazovsky District of Primorsky Krai

An analysis of mortality in the native population of the subspecies of sika deer, Cervus nippon hortulorum Swinhoe, 1864, was conducted in the Lazovsky District of Primorsky Krai, Russian Federation, covering the period from 1958 to 2023, including the Lazovsky Nature Reserve. Causes of death were determined for 2702 individuals based on the study of their remains. The primary mortality factors in the study area were poaching, predation by wild carnivores, and starvation during severe, snowy winters. Overall, anthropogenic factors accounted for 58.58% of sika deer deaths, including attacks by feral domestic dogs. Wild predators were responsible for 26.09% of deaths, while natural mortality (starvation and other causes) accounted for 13.54% of the total. Between 1958 and 1975, sika deer mortality was predominantly due to wild predators; however, since the 1990s, poaching has become the leading cause of death, with its intensity increasing in the Lazovsky Nature Reserve since the 2000s. Given the identifi ed trend of escalating poaching pressure, additional conservation measures are urgently needed to protect the Ussuri sika deer subspecies in the southeastern Sikhote- Alin region.