ИСТИНА

Acrocephalid reed warblers are among the most complex and variable singers in songbirds. They are also the most monomorphic passerines which make them difficult to identify and the most reliable marker for their field identification is the song. Using the comparison of molecular and acoustical data we might have a glimpse of how this structurally complex songs have evolved. We analyzed time-and-frequency parameters of songs of 5 species from subgenus Notiocichla that includes species with richest repertoires. It appears to be that basal species of the group, the Blyth's reed warbler (Acrocephalus dumetorum), tend to have longer elements and pauses between them and less variability of elements. Discriminant analysis showed that two species of the basal group are distinguished quite clearly while the division of the rest is not that clear. Still, there are also some interesting trends there as well. For example, two subspecies of Paddyfield warbler (A. agricola) are divided quite clearly while the sister species Blunt-winged warbler (A. concinens) is not clearly distinguished from A. agricola septima.