Birds of Indian Subcontinent

Territorial Behavior, Hormonal Changes, and Body Condition in an Arctic-Breeding Song Bird, the Redpoll (Carduelis flammea)

Publication Type:Journal Article
Year of Publication:1997
Authors:L. Romero, M, Soma, KK, O'Reilly, KM, Suydam, R, Wingfield, JC
Date Published:1997
ISBN Number:00057959
Keywords:Acanthis, Acanthis flammea, Carduelis, Carduelis flammea, Fringillidae
Abstract:The redpoll is a small, wide-spread arctic-breeding song bird. Despite previous publications suggesting that breeding redpolls are not territorial, simulated intrusions (placing a decoy male near the nest) elicited aggressive territorial-like behavior from many male and female redpolls, and often simultaneous territorial responses from multiple males. Thus, even though redpolls are gregarious throughout the breeding season, they will respond vigorously to a territorial intrusion and may cooperate in territorial defense. In males, testosterone and luteinizing hormone (LH) levels peaked as they reached the breeding grounds and gradually decreased throughout the breeding season, consistent with hormonal patterns shown in males of other arctic-breeding passerines. Fat stores also decreased soon after arrival and recovered as males began feeding young. In females, neither testosterone nor estradiol were detectable, nor did LH titers vary, at any time during the season. Fat stores and body weight of both sexes gradually increased from 09:00 to 24:00 despite constant sunlight, whereas hormonal titers did not show this rhythm. Finally, a wide range of male plumage variations (red color of the throat and breast), possibly affecting mate choice, did not correlate with physiological measures such as testosterone and body condition.
Short Title:Behaviour
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith