Ways and regularities of the social evolution in pied woodpeckers (Genera Dendrocopos
et Picoides; Picidae; Aves). - W.S. Friedmann. - Berkut. 6 (1-2). 1997. - P. 52-66;
7 (1-2). 1998. - P. 82-93.
The unique detail of pied woodpeckers' social organization, which help to understanding
an adaptive nature all other parts their social system, is described. In social
life of Picus- and Dryocopus-species during the year cycle all the
forms of territoriality arise only after the beginning of courtship activity.
They are induced from whole courtship behaviour, but social life by pied woodpeckers
is organized the wrong way round. Their courtship behaviour arises only after
strengthening the autumn territorial structure. It is successfully only, if the
territory defense and supporting it's internal functional participation is successfully.
For normal courtship only successfully defense of non-nesting territory is necessary
and a defense of nesting pair territory have not causal connections with mating
success. Because these all the pied woodpeckers mate in autumn; in spring the
pair, appeared in autumn, only re-established. During the progressive social evolution
in pied woodpeckers group we see the progressive emancipation the courtship behaviour
from their inductor - a territorial behaviour - and the establishing an own mechanisms
for work and stability the courtship behaviour in woodpeckers social system. We
can interpret these data in the phylogenetic scenario consisted in 4 stages progressive
evolution of sociality, which are described in the article. [Russian].
Key Words: pied woodpeckers, evolution, phylogeny, social behaviour, territoriality, courtship.