AVIS-IBIS

Birds of Indian Subcontinent

Survival benefits of post-fledging care: experimental approach to a critical part of avian reproductive strategies

Publication Type:Journal Article
Year of Publication:2010
Authors:Grüebler, MU, Naef-Daenzer, B
Journal:Journal of Animal Ecology
Volume:79
Issue:2
Date Published:2010
ISBN Number:1365-2656
Keywords:avian life history, Hirundinidae, Hirundo, Hirundo rustica, juvenile survival, parental care, post-fledging period, reproductive effort
Abstract:1. Caring for offspring beyond leaving the nest is an important but under-studied part of avian life histories. Theory predicts that prolonged post-fledging parental care should yield fitness benefits such as increased fledgling survival. Post-fledging care is also costly in terms of time and energy available for subsequent reproduction, moult or migration. So far, direct measurements of the fitness effects of the duration of post-fledging parental care are lacking. 2. In a partial cross-fostering experiment, barn swallow (Hirundo rustica) chicks were exchanged among broods close to fledging. Thereby, we separated the effects of post-fledging care from those of pre-fledging origin on juvenile survival. 3. Prolonging post-fledging care substantially increased juvenile survival up to 3 weeks post-fledging. Juvenile mortality was maximal in the days following the termination of parental care, and prolonging care delayed and reduced this peak mortality. Survival of fledglings experiencing 6 days of care was Φ = 0·227, whereas fledglings experiencing 14 days of care showed a survival of Φ = 0·571. 4. Offspring from pairs providing short care showed lower post-fledging survival than did offspring from pairs providing long care, irrespective of the actual duration of care experienced. This gives evidence for an additional survival effect of pre-fledging factors associated with the parental duration of care. 5. The results suggest that differential survival in relation to post-fledging parental care is a major fitness component. This relationship has profound effects on the reproductive trade-offs underlying the evolution of avian life histories.
URL:http://dx.doi.org/10.1111/j.1365-2656.2009.01650.x
Short Title:Journal of Animal Ecology
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith