Survival rates and causes of mortality of Amur tigers on and near the Sikhote‐Alin Biosphere Zapovednik

Abstract

Abstract We examined causes of mortality and survival rates for Amur tigers on and near the Sikhote‐Alin Biosphere Zapovednik. Our objectives were to estimate and compare survival rates among sex and age classes, estimate cause‐specific mortality, identify conservation issues related to tiger mortality and provide recommendations for reducing human‐caused mortality. We used two separate datasets; one based on radio‐tracking tigers from 1992 to 2005 and one based on reports of dead tigers from 1976 to 2000. We examined causes of mortality for both datasets and used a Cox proportional hazards models to estimate survival rates using data from 42 radio‐collared tigers. Mortality was predominantly human‐caused for both datasets (83% for the telemetry dataset and 78% for the other, n =24 and 53 mortalities, respectively), and 75% of collared animals were poached. All collared subadult tigers that dispersed were poached ( n =6). Annual survival of adult females (0.81±0.10) was greater than that of adult males (0.63±0.20) ( z =1.52, P =0.13) and subadult males (0.41±0.46) ( z =2.07, P =0.04). Survival rates were precariously low on our study area, which included the largest protected area within Amur tiger range. Efforts to reduce human‐caused mortality should focus on poaching and reducing deaths from tiger–human conflicts.