Dietary diversity and niche partitioning of carnivores across the Qinghai–Tibetan Plateau of China using DNA metabarcoding

Abstract

Abstract Understanding predator guild resource use is vital for carnivore species preservation and ecosystem function in high-altitude landscapes. We describe the dietary composition, similarity, and niche overlap for seven carnivore species across three regions of the Qinghai–Tibetan Plateau (Qilian Shan, East Burhanbuda Mountain, Yushu) using DNA metabarcoding of 760 scat samples. Analyses found 33 unique prey items representative of the classes Mammalia, Aves, and Actinopterygii. Blue sheep (Pseudois nayaur) and pika (Ochotona sp.) were most frequently detected. Livestock in carnivore diets ranged from 4% to 7% depending on site, but accounted for 21.7% of Tibetan wolf (Canis lupus) diet. Eurasian lynx (Lynx lynx), Tibetan fox (Vulpes ferrilata), Pallas’s cat (Otocolobus manul), and snow leopard (Panthera uncia) had highly uneven diets. Intraguild predation of mesocarnivores by apex carnivores was found. Analysis of dietary niche overlap using Pianka’s index showed that overlap was significantly greater than expected among all carnivores examined and between apex and mesocarnivores, though significant correlations between carnivore body mass and prey body mass suggested broad separation in consumed prey. Snow leopard and Tibetan wolf diets were consistently the most similar of any two given species pairs. This study provides evidence of high dietary overlap. Protection for species consumed by a wide variety of carnivores will benefit predator guilds in the area and assist in maintaining the relatively low frequency of livestock predation. This work provides insight into the dynamics of carnivore guilds living in an area that has worldwide impacts, and methods herein could be applied on global scales for conservation efforts.