Sunday, October 2, 2011

The Alpine Accentor Prunella collaris

Family: Prunellidae Accentors
English: Accentors
Spanish: Acentores

The Alpine Accentor, Prunella collaris, is a small passerine bird found throughout the mountains of southern temperate Europe and Asia at heights above 2000 m (breeding). It is mainly resident, wintering more widely at lower latitudes, but some birds wander during winter months as rare vagrants even as far as Great Britain. This is a small-sized bird at 15-17.5 cm in length, slightly larger than its relative, the Dunnock Prunella modulari. It has a streaked brown back, adults have a grey head and red-brown spotting on the underparts. It has an insectivore's fine pointed bill, but as with all accentors it will also feed on seeds. Sexes are similar, although the male may be more brightly coloured (especially in the spring) in appearance. Young birds have browner heads and underparts.

Outside of the related Dunnock, P.modulari, this species has the most widespread, if somewhat fragmented, distribution of the accentors, although much more limited by available habitat and altitudinal range. These birds are found in mountainous areas, from the Iberian Peninsula and northwest Africa, through France and Italy and Slovenia and into the Balkans, Bulgaria and Greece. They are also found in northern and eastern Turkey, through the Caucasus and Iran and east to Turkmenistan, China, Korea and Japan. They are also found in Taiwan.

During the breeding season it is a bird of bare mountain areas with some low vegetation. It builds a neat nest low in a bush or rock crevice, laying 3-5 unspotted sky-blue eggs. It is Polygyandrous in its relationships and has a very interesting strategy. Home ranges are occupied by breeding groups of 3 or 4 males with 3 or 4 females. These are unrelated birds which have a socially polygynandrous mating system. Males have a dominance hierarchy, with the alpha males being generally older than subordinates. Females seek matings with all the males, although the alpha male may defend her against matings from lower ranking males. In turn, males seek matings with all the females. DNA fingerprinting has been used to show that, within broods, there is often mixed paternity, although the female is always the true mother of the nestlings raised within her nest. Males will provide food to chicks at several nests within the group, depending on whether they have mated with the female or not - males only provide care when they are likely to be the true fathers of the chicks.

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