Willow (Lagopus lagopus, L., 1758) and rock ptarmigans (L. mutus, Montin, 1776) on the areas of joint habitat (on example of Central Verkhoyanie)

The region of joint distribution of Willow and Rock ptarmigans occupies a vast area in Central Verkhoyanie. During the breeding period, a reduction in Willow ptarmigan number is above the level of 700-800 m above sea level. The lower boundary of Rock ptarmigan distribution is at an altitude of 650 - 750 m, and upper 1100-1200 m above sea level. In normal years, breeding territories of Willow and Rock ptarmigans are divided with biotopes and Rock ptarmigans inhabit the mountain slopes while Willow ptarmigans use the lower valley complex. This scheme is complicated in years of increasing abundance when both species were seen in absolutely identical, at first glance, the habitats. A comparison of the food of these species shows some similarities and at the same time there are remarkable differences. Compared with Willow ptarmigan, Rock ptarmigan male mating activities have at a later time.