The Despotic Distribution and Deferred Maturity: Two Sides of the Same Coin

For an individual, the decision on when to settle (i.e., at what age) cannot be separated from the decision on where to settle (i.e., in which habitat). We tackle both problems simultaneously by treating territory settlement in the long-lived oystercatcher Haematopus ostralegus (in which territories differ strikingly in quality and many individuals delay settlement) as a career decision with long-term fitness consequences through its effect on social status. We reject the hypothesis that oystercatchers are not able to judge territory quality or that short-term advantages of a high-quality territory are offset by long-term costs. We estimate the expected future reproductive success (EFRS) of birds of different social status on the basis of a Markov model. A simple contest model shows that owners of high-quality territories must have a considerable advantage that allows them to despotically exclude other birds. We find no evidence for a phenotypic superiority of owners of high-quality territories. Also, the act of breeding, even in a poor territory, does not enhance the probability of subsequently settling in a good territory. The available data support the queue hypothesis that unsettled individuals must develop site dominance in order to overcome the owner advantage. By queuing for a specific territory, an individual reduces its chances of becoming established elsewhere. At evolutionary equilibrium, the local queues for high-quality territories are longer, which implies longer waiting times and a higher probability of premature death. This trade-off between territory quality and waiting time links the despotic distribution to deferred maturity and provides a partial explanation for both.