Distributing eggs among multiple nests may have a selective advantage over laying eggs in one nest when stochastic events, such as predation, affect individuals of the same phenotype differently. However, an earlier analysis revealed that the mean fitness of such an egg-spreading strategy is equal to putting all eggs in one nest when predation destroys entire clutches. However, if predation typically results in partial clutch loss, distributing eggs among multiple nests may provide a selective advantage. We investigated the possibility that partial clutch loss could favor egg-spreading strategies by modeling mean fitness under a variety of egg-distribution strategies with partial nest predation. We found that higher fitness resulted from distributing eggs among multiple nests that contained at least as many eggs as a single nest containing the eggs of one female. The highest fitness resulted when eggs were in large clutches, because of predator-dilution effects. The fitness differences among egg-distribution strategies increased as predation rates, frequency of partial clutch loss, and the number of eggs destroyed in each partial predation event increased. We also examined the invasibility of pure and mixed parasitic and nesting strategies. Nest parasites may increase their fitness by spreading eggs among multiple nests that contain more eggs than would be present if they were nesting alone, but only a pure parasitic strategy can invade a population of nonparasites when the number of eggs laid is constrained.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.
Vol. 125 • No. 3