Penetrating of northern dendrophilous bird species into the depth of Kazakhstan
deserts. - V.P. Belik. - Berkut. 6 (1-2). 1997. P. 19-22.
In Guryev region of Kazakhstan the distribution of 9 bird species was specified in the valley of the Lower Ural river in 1987-1991. During 20th Century 7 species penetrated along the Ural river to the South on the distance in 100-400 km with an average speed of 2-6 km per year. Now some species increase the speed of expansion that is connected with the climate damping. Analysis of this process show that the current expansions are a gradual filling of the postpleistocene faunistic vacuum within palearctic ecosystems. [Russian].
Key words: Ural, Kazakhstan, fauna, breeding range, distribution, expansion.