Analysis of population viability analysis of Yangtze finless porpoise in different simulated scenarios

Abstract:

To study the population dynamics and conservation strategies of the Yangtze finless porpoise (Neophocaena asiaeorientalis asiaeorientalis), Vortex (v.10.3.7.0) was used to analyze the population viability. Taking 1999 as the starting point, a retrospective analysis revealed that the extinction probability of finless porpoise was most likely to be 0.0754 and was not higher than 0.5629. The mean extinction time was most likely to be 93.5 years and not less than 87.9 years. Taking 2017 as the starting point, through the analysis of the current situation, it was found that the extinction probability of the Yangtze finless porpoise population was 0.3551~0.6985, and the average extinction time was 83.5~88.0 years. In certain situations, the proportion of newborn male Yangtze finless porpoise was 0.55, 0.50, and 0.45, respectively. The results showed that masculinization increased the probability of extinction from 0.6985 to 0.9157, and feminization brought it down to 0.3664. At the same time, comparison of the data found that a 10% decrease in the proportion of newborn males and a 10% increase in the breeding rate of adult females had the same effect. The above results suggested that the extinction risk of the finless porpoise population in the Yangtze River was relatively high. Focusing on the protection and restoration of high-quality habitats, especially those related to parents–children, is important for the protection of the Yangtze finless porpoise.