ИСТИНА

Although 4/5 of passerine species inhabited tropics, the vast majority of avian studies (> 99%) were conducted in the temperate zone. The Old World Suboscines (Eurylaimides) is a peculiar group of passerines, long ago diverged from Oscines. They have a number of morphological features which are the cause for some researchers to regard them as the most primitive group in the order Passeriformes. In contrast to the New World Suboscines (which number more than 1100 species), there are only about 50 species of the Old World Suboscines. Biology of the most of them, including broadbills (Eurylaimidae) is still almost unknown. In this work I have studied the nest-building of two species of broadbills from monospecific genera (Dusky Broadbill Corydon sumatranus and Black-and-red Broadbill Cymbirhynchus macrorhynchos). On the basis of almost 200 nests found in three field seasons, I described the location and surroundings of nests in both species. The behavioral data set was based on visual observations during the nest-building for about 50 hours and over 25 hours of video recordings. 12 nests were untwined in detail. The nest-building behaviour of both species and structural features of their nests were described. Some methods of nest-building were found to be unique in birds. The material used by broadbills and the ways of its application were also studied.