ZUGUNRUHE ACTIVITY IN CASTRATED BRAMBLINGS FRINGILLA MONTIFRINGILLA

Publication Type:	Journal Article
Year of Publication:	1961
Authors:	Lofts, B, Marshall, AJ
Journal:	Ibis
Volume:	103a
Issue:	2
Date Published:	1961
ISBN Number:	1474-919X
Keywords:	Fringilla, Fringilla montifringilla, Fringillidae, Montifringilla
Abstract:	Summary 1. Zugunruhe, a condition of nocturnal activity in caged migratory birds that is generally held to be identical to premigratory restlessness in the wild, developed in the spring in captive castrated male Bramblings Fringilla montifringilla. 2. Zugunruhe occurred in intact control birds about a week before it was recorded in castrates. Intact birds became restless each evening earlier than did the castrates. 3. Nevertheless, the peaks of intensity in both castrate and intact birds occurred at the same time and coincided with the period during which the bulk of the wild population migrated to their northern breeding grounds. 4. In intact birds Zugunruhe occurred during the initial period of seasonal gonad modification. It waned by the time of sperm-production when, under wild conditions, the birds would have completed their journey to their distant breeding grounds. 5. The data suggest that the seasonal phenomena of migratory unrest and gonad development occur independently of each other. The remote possibility that migration is influenced by extra-testicular androgens is mentioned.
URL:	http://dx.doi.org/10.1111/j.1474-919X.1961.tb02432.x
Short Title:	Ibis

Taxonomic name:

AVIS-IBIS