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Nesting bird communities of individual habitat types in the Arkaim reserve are formed every year under the influence of nonrandom factors. Their qualitative and quantitative composition may gradually shift in a certain direction, but more often it remains relatively stable over several years and then makes an abrupt transition into a different state. The strongest effect on the dynamics of these communities has been exerted by progressive succession following the assignment of special protection status to the Arkaim area. The effects of fires and other elemental factors are also significant.

In male willow ptarmigans, the relationship between qualitative differences between birds belonging to different intrapopulation groups and some individual features of male nuptial plumage has been revealed by studying banded birds. Thus, males that have changed their nesting site differ from those returning to the former site and bigamous males differ from monogamous in the number and size of dark spots amid the white plumage. The influence of the time of the onset of spring on the development of nuptial plumage is considered.

The return of willow ptarmigans to the sites in which they nested the previous year has been studied using color banding. No factors influencing the return index have been revealed, except for its dependence in males on the time when spring begins in a given year. In northernYamal, in contrast to the temperate zone, some surviving birds fail to return to their former nesting sites. Polymorphism of individuals with respect to territorial behavioral strategy is proposed for L. lagopus populations at the northern boundary of the species range.