Redpoll (Carduelis flammea) Science Article 3
This paper is a sequel to an earlier paper on the Lesser Redpoll (Evans 1966a), in which I discussed the timing of its annual (post-nuptial) molt in relation to the timing of breeding and autumn migration and described variations in the total weights of birds during late summer and autumn. This paper extends two facets of the previous work: (1) movements of Redpolls in relation to food, particularly the seed crop of birch (Be&&z), and (2) weight changes, which are re-assessed in the light of analyses of body composition and fat content during molt, prior to and during migration, and on the wintering grounds. First half of the present paper describes the effects of variations in food availability on the habits of Redpolls during the parts of their annual cycle from the end of breeding until the following spring, and is based on fieldwork carried out in three areas: Roughtinglinn (near Ford) and Craster, both in Northumberland (fig. 1) in northern England (55?4’N), and Wytham, Berkshire, about three miles from Oxford in southern England (51%’N). Roughtinglinn is an area of damp birch woodland, surrounded by young conifer plantations, in the foothills of the Cheviot Hills.
P. R. Evans, The Condor, 71:316-330, 1969