Nest-Related Activities of Black-Billed Magpies

Abstract

American corvids, the crows and jays. Their predation on eggs of gamebirds and their habit of feeding on grain and other livestock forage in feedlots have led to the classification of magpies as pests over much of their range. In spite of the species' abundance and economic importance, many basic aspects of its breeding ecology and behavior are poorly or only superficially known. Linsdale (1937) reviewed the available literature on magpies and reported some personal observations, primarily on the Yellow-billed Magpie (Pica nuttalli), regarding ecology and behavior. Evenden (1947) commented on nest heights and location, clutch size, incubation periods, and nestling periods for several nests in Idaho. Breeding ecology of Idaho magpies was studied by Jones (1960). Available information regarding activities of magpies in relation to their prominent nests, however, remains largely speculative or anecdotal. This report concerns nest ecology and nest-associated behavior of magpies near Laramie, Wyoming.