Habitat use and diel activity pattern of the Tibetan Snowcock (Tetraogallus tibetanus): a case study using camera traps for surveying high-elevation bird species

Background Global climate change has had significant effects on animal distribution and population dynamics in mid-latitude alpine areas, but we know little about the basic ecology of high-altitude species due to the difficulties of conducting field research in the harsh climate and habitat present at high elevations. The Tibetan Snowcock (Tetraogallus tibetanus) is a little-known phasianid distributing in alpine areas at extremely high elevations in the mountains surrounding the Tibetan Plateau. Estimating the species occupancy rate and discussing the factors affecting its distribution based on infrared-triggered camera techniques would provide both a baseline to measure the influence of global warming and valuable information on its conservation and ecology.

Methods We used infrared-triggered cameras to investigate the Tibetan Snowcock on the western slope of Mt. Gongga from June to November 2016. We used the R package "overlap" to visualize its activity pattern, and used an occupancy model to both examine its habitat use as well as to determine the most influential variables affecting its habitat use.

Results Using 103 camera traps over 9213 camera-days, we recorded 428 instances of Tibetan Snowcock. The diel activity peaks of Tibetan Snowcock occurred during the periods of 8:00-10:00 am and 18:00-20:00 pm. The model estimate of occupancy for Tibetan Snowcock (0.830) was slightly higher than the na?ve site occupancy based on camera detections (0.663), indicating a wider use of habitat than the camera traps recorded. Elevation, slope, settlement density, road density, and EVI (enhanced vegetation index) were the most influential variables for its habitat use.

Conclusions The Tibetan Snowcock is confirmed to be diurnal. This species prefers an environment with a high elevation, gentle slope, and low EVI, apparently facing a trade-off between predator risk, foraging efficiency, and food availability. When human impact was low, there was a positive correlation between the habitat use of the Tibetan Snowcock and both its road and settlement densities. Infrared cameras and proper survey design are valuable for investigating extreme alpine phasianids.