Selection for the Timing of Great Tit Breeding in Relation to Caterpillar Growth and Temperature

Abstract

JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org.. British Ecological Society is collaborating with JSTOR to digitize, preserve and extend access to Journal of Animal Ecology. Summary 1. We investigated the relation between the timing of great tit breeding, measured as the mean date of laying the first egg in each clutch, the timing of caterpillar availability, measured as median pupation dates of winter moth, selection for laying dates, measured from the recruitment into the local breeding population in subsequent years, and temperature in the period after egg laying. 2. There was a significant positive correlation between the timing of the great tit's laying and the timing of the caterpillars. 3. In most years there was selection for earlier laying in this great tit population. The selection differentials were usually the same for male and female recruits. 4. The selection differential for laying date was strongly correlated (r = 0-84, n = 21, P < 0-0001) with the difference in timing between birds and caterpillars. This difference in timing was in turn strongly correlated with temperatures in the period after egg laying. 5. When the period after the laying date was subdivided, the selection differential was strongly correlated with the mean temperature during the period when most birds were incubating. 6. We discuss six alternative hypotheses explaining a consistent selection differential for earlier laying. One of these is new and is based on the fact that the birds can delay their breeding more succesfully than they can speed it up, once they have started laying.

Non–random fitness variation in two populations of Darwin's finches

“…Temperatures and food supply vary in both non-breeding seasons and at the beginning of breeding. This causes marked variation in survival and local recruitment, mediated by variation in food supply, the timing of breeding and local density (Hochachka et al 1989;Van Noordwijk et al 1995;Visser et al 1998;Both et al 1999;. Such details illustrate the general importance ascribed to environmental variation in determining low (or zero) heritabilities of life-history traits and ¢tness itself (Charlesworth 1987;Price & Schluter 1991).…”

Climate change and the risks associated with delayed breeding in a tropical wild bird population

“…The mechanisms through which climate change impacts on biodiversity are varied, but one potentially important mechanism concerns changes in phenology [4]. There is an increasing number of examples now showing changes in the timing of important ecological events, such as flowering in plants and reproduction in animals, in response to climate change [4][5][6][7][8][9].…”

Foraging mode shifts of four insectivorous bird species under temporally varying resource distribution in a Japanese deciduous forest

“…It is, therefore, expected that temporal changes in foraging behavior among birds in response to the abundance and distribution of arthropods should affect the fitness of individual birds, and hence the structure of the avian community. Although van Noordwijk et al (1995) suggested a relationship between the timing of Great Tit breeding and the availability of Lepidoptera larvae as food for their fledglings, the responses of birds to temporal changes in resource abundance and distribution have been little studied. Further understanding of species-specific responses of birds to temporal changes in resource abundance and distribution in deciduous forests in spring will help to explain the composition of local bird communities (cf.…”