Scientific publications

We studied the territorial behaviour of typical warblers, namely Blackcaps Sylvia atricapilla, Garden Warblers S. borin, Whitethroats S. communis, and Lesser Whitethroats S. curruca, in the habitats occupied by them with the high local population density (to 67 pairs/sq.km at the Courish spit of the Baltic Sea, Russia) and low population density (1 pair/sq.km and even lower at the Republic of Karelia, Russia). We supposed that specifics of the territorial behaviour may be one of the adaptation mechanisms to the different social conditions, first of all, related to population density, and we aimed at investigation of this hypothesis. We found that Sylvia warblers’ territorial behaviour has a high degree of plasticity and depends on population density. Particularly, sizes of conspecific males’ territories and distances between them were getting lesser with increasing of population density. Also under the high population densities, we observed the most variety of behavioural patterns, including ones nonspecific for these birds. At very high and very low population densities, bird territoriality was partially reduced. The differences in the territorial behaviour presumably direct to the maximum realization of the reproductive potential in different environmental conditions. This study was supported by RFBR, research project NN. 12-04-31872 and 15-05-03493_а.