Nestlings leave the nest after 30-32 days. Once the chicks have hatched, all group members participate in providing food. The incubation period is 11 days and both male and female breeders incubate. Eggs are laid at approximately 24 hour intervals. The average clutch size for a singleton female is four eggs. Average clutch size for a group with more than one female is five white, elliptical eggs. The inside of the nest cavity is lined with fresh wood chips, and nest holes may be used repeatedly for several seasons. Nest cavities are drilled into large dead or living limbs in trees or snags, which may contain granaries. Courtship and pair-bonding displays are absent. Reproduction competition between males is displayed by attempts by a male to disrupt copulation between another pair. After females have established a normal laying sequence, egg destruction stops. There is often extreme reproductive competition between joint-nesting females, who regularly destroy eggs laid by their cobreeders. In groups that contain more than one female breeder, the female cobreeders lay their eggs in the same nest cavity. Generally, Acorn Woodpecker groups contain 1-7 male breeders that compete for matings with 1-3 egg-laying females. Mating systems of Acorn Woodpeckers range from monogamy in some populations to cooperative polygyny.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |