Age structure and movement of the common raven Corvus corax principalis Ridgway captured at Gaspereau, Kings County, Nova Scotia, in winter

To determine the age structure and movement of the Common Raven (Corvus corax principalis Ridgway), 171 ravens were trapped, aged and individually color-marked at Gaspereau, Kings Co., Nova Scotia, and observed at Gaspereau and other locations from November 27, 1977 to March 3, 1978. Of those captured, 70, 21 and 9% were juveniles, subadults and adults, respectively. The change in proportion from the juvenile to the subadult age-class may be due to high mortality of juveniles before November of their second year. One hundred and twenty-five or 73% of the ravens color-marked in this study and 51 or 34% of the 150 birds color-marked during the previous winter were sighted, retrapped or both sighted and retrapped. Much movement of ravens away from the study area was evident as the same color-marked birds were not present every day. Observations of color-marked birds in three counties of central Nova Scotia verified this. With respect to the proportion comprising each age-class in 1977-'78, fewer juveniles were seen than subadults or adults. Adults were observed more often at just one location than ravens of other ages. It is thought that movement may be related to breeding status. Non-breeding birds may wander more extensively and frequently than breeding ravens.