Should I stay or should I go? Natal dispersal in the Seychelles warbler
|Date:||March 14, 2008|
The dispersal from the place of birth to the place of first reproduction is one of the most important steps in the life of an individual. In his thesis Cas Eikenaar studied the patterns of dispersal of young Seychelles warblers and attempts to explain the individual differences in the distance and timing of dispersal.
Agreeing with the general trend in birds, female Seychelles warblers settle further from their natal territory than males. For males, dispersal distance decreases with increasing local breeding density, whereas females avoid settling in adjacent territories, no matter what density. Theory predicts that this sex-difference result from inbreeding avoidance. However, the distribution of relatives in the population reveals that the female-bias in dispersal distance does not contribute to inbreeding avoidance.
The identity of the dominant breeders in the natal territory appears to be an important determinant of the timing of dispersal. When a parent dies and is replaced by a stepparent, the young usually disperse immediately. Parental tolerance of their young thus seems to have contributed to the evolution the family. Moreover, young that have the opportunity to delay their dispersal have a higher chance of acquiring their own territory later in life. Also the age of young that compete over territories influences the settlement success, however only in males. In this species competition over territories is stronger in males, because territory ownership is a prerequisite for males only.
PhD ceremony: C. Eikenaar, 16.15 uur Academiegebouw, Broerstraat 5, Groningen
Promotor(es): prof.dr. J. Komdeur
|Last modified:||September 04, 2012 16:27|