Inbreeding depression and population viability analysis of the South China tigers (Panthera tigris amoyensis) in captivity

The South China tiger (SCT) is close to extinction in the wild and the captive population may be the only hope of saving this species. Based on the international studbook of the SCT from 1956 to 2019, the life history and population parameters were summarized, and lethal equivalents (B) were estimated. Population viability analysis (PVA) was carried out to simulate the population dynamics and the effects of key factors influencing population dynamics were assessed on the basis of sensitivity analysis, including lethal equivalent, sex ratio, percentage of females breeding and percentage of males breeding. The average B value for the captive SCT population was estimated to be 4.24 at the population level. The captive population of SCT is currently growing up, with a positive growth rate of 0.093 (SD = 0.088) and a probability of extinction of 1% within the next 100 years. The current SCT population is sensitive to lethal equivalents (S = 2.30) and the percentage of females breeding (S = 1.94). We suggest a feasible breeding plan that can practically reduce the effect of inbreeding, and better husbandry practices to improve the percentage of females breeding.