The impact of climate change and human activities over the past 2000 years has increased the spatial-temporal extinction rate of gibbons

Climate change and human activities can drive extinction risk by limiting and fragmenting species distributions, and reducing effective population size. However, it is difficult to quantify the degree to which species decline is due to climate change, human activities, or a combination of both factors. Here, we present data on changes in gibbon distribution over the past 2000 years, along with expected patterns of climate change to predict future changes in gibbon distribution and population survival. We found that local gibbon extinction rates and range contraction in China increased significantly over the past 2000 years, from 0 % between 0 and 800 CE to 5 % from 801 to 1700 CE, to 30 % from 1701 to 1950 CE, and 71 % from 1951 to 2020 CE. Based on genetic evidence, the effective population size of the northern white-cheeked gibbon (Nomascus leucogenys) in China decreased by 8 % between 0 and 800 CE, 15 % between 801 and 1700 CE, 48 % between 1701 and 1950 CE, and 100 % between 1951 and 2020 CE. In addition, over the past 2000 years, China's human population density increased from 17.56 individuals/km2 to 60.68 individuals/km2. Human population increase was positively correlated with the conversion of forested habitats into anthropogenic landscapes, and this was found to be a more significant factor than climate change in driving gibbon range decline and population extinction. Climate models predict that by the year 2050, the availability of suitable habitat for three gibbon species in China is expected to decrease by 23 %-91 %. Our results indicate that unless immediate and effective action is taken to protect gibbons and their habitats from the deleterious effects of climate change and a large human population, all species of gibbons in China will likely go extinction by the end of the century.