AVIS-IBIS

Birds of Indian Subcontinent

Stress Responsiveness Decreases With Age in Precocial, Juvenile Chukar

Publication Type:Journal Article
Year of Publication:2010
Authors:Dickens, MJ, L. Romero, M
Journal:The Wilson Journal of Ornithology
Volume:122
Issue:4
Date Published:2010
ISBN Number:1559-4491
Keywords:Alectoris, Alectoris chukar, Alectoris kakelik, Phasianidae
Abstract:Abstract Development of the hypothalamic-pituitary-adrenal (HPA) axis and subsequent corticosterone (CORT) release in newly hatched birds is a balance between limiting exposure to the detrimental effects of CORT on growth and development, and the necessity of mounting an acute stress response. We measured the stress responsiveness of juvenile Chukar (Alectoris chukar) 20 to 60 days post-hatch prior to molting into full adult plumage. The integrated CORT response during 60 min of restraint in these individuals decreased with age. Comparisons to mean adult integrated CORT values imply the youngest juveniles have greater responses than adults while the oldest juveniles have reduced CORT responses. This pattern is currently an anomaly within the altricial-precocial range and suggests specific tradeoffs, such as molting into adult plumage, may affect timing of HPA suppression during development.Abstract Development of the hypothalamic-pituitary-adrenal (HPA) axis and subsequent corticosterone (CORT) release in newly hatched birds is a balance between limiting exposure to the detrimental effects of CORT on growth and development, and the necessity of mounting an acute stress response. We measured the stress responsiveness of juvenile Chukar (Alectoris chukar) 20 to 60 days post-hatch prior to molting into full adult plumage. The integrated CORT response during 60 min of restraint in these individuals decreased with age. Comparisons to mean adult integrated CORT values imply the youngest juveniles have greater responses than adults while the oldest juveniles have reduced CORT responses. This pattern is currently an anomaly within the altricial-precocial range and suggests specific tradeoffs, such as molting into adult plumage, may affect timing of HPA suppression during development.
URL:http://dx.doi.org/10.1676/09-185.1
Short Title:The Wilson Journal of Ornithology
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith