Breeding ecology of the Snow Partridge (Lerwa lerwa) in high-altitude regions, Tibet

To explore the environmental adaptation strategies of high-altitude breeding birds to alpine regions, we studied the breeding ecology of the Snow Partridge (Lerwa lerwa) in the Qinghai-Tibet Plateau. Incubation behavior was determined using data loggers in Basu County (2018) and Cuona County (2019), in the Tibet Autonomous Region, China. We monitored seven Snow Partridge nests; clutch sizes ranged from 4-5 eggs per nest (mean = 4.71 +/- 0.45 eggs, N=7), egg mass ranged from 28.1-37.7 g (mean=31.1 +/- 2.5 g, N=28), and the hatching success rate was 87.9% (N=33 eggs, six nests hatched successfully, and one nest suffered a predator attack). Nesting females typically took 1-4 recesses each day (mean=1.8 +/- 0.7, N=39 days). In five females, the first daily recess occurred at 0601 to 0709 (mean=0626 +/- 16 min, N=39 days) and the duration ranged from 60 min to 615 min (mean=179 +/- 102 min, N=39 days). The average nest attendance was 85.6 +/- 5.9% (75.9-92.8%, N=6 nests). Compared with other Galliformes, Snow Partridges lay larger eggs and smaller clutches, leave their nests fewer times per day but with a lower nest attendance, and a bimodal pattern of recess timing. Additionally, Snow Partridges build cave nest structures. These characteristics are highly adapted to the alpine region of the Tibetan Plateau and balance the thermal needs of the developing embryos and the self-maintenance needs of the incubating females.