At present, all the basic habitats of G. japonensis
(left tributariers of Zeya River, Bureinsko-Arkharinskaya lowland, a basin of Bolon Lake and Khanka Lake) as well as a number of small colonies and separate pairs were evidently found out. Additional information on Grus japonensis
inhabiting the South Kuriles was obtained. Numbers of birds nesting annually in Priamurye ranges approximately from 5-7 to 15 pairs (Smirensky & Roslyakov 1982). In 1980 16 pairs were registered in Primorye and in 1981 there were 18-19 successfully nesting pairs. Some pairs of this bird can be assumed to nest on the South Kuriles.
Basins of the Amur and Ussuri Rivers are the real limit of G. vipio
distribution on north and east. The nesting grounds of this species established recently are small colonies at the margin of the area. Due to approximate estimates a total number of the reproductive part of population hardly exeeds 20 pairs.
The total number of G. japonensis
and G. vipio
stopping in the lower reaches of Tumannaya River every spring, ranges from several dozens to 150-200 birds of each species.
Further studies on distribution and numbers of both species are needed (searches of unknown nesting grounds, verification of questionable places for nesting, refinement of limits of known nesting grounds, carrying out the regular censuses and marking).