The use of primary abrasion in ageing Siskins carduelis spinus

Abstract

This paper presents information regarding the use of primary abrasion for ageing Siskins. 96% of the Siskins examined could be aged from the degree of primary wear, juvenile outer primaries usually being more abraded than adults. A four point scale was used to classify the degree of abrasion. This ageing technique may be useful for other species of passerines that undergo a partial post-juvenile moult and the adults a complete post-breeding moult. © 1996 Taylor and Francis Group, LLC.