Environmental Influences on Roost Selection in Wintering Ravens at Churchill, Manitoba, Canada^*

* A version of this paper was presented at the Circumpolar Ecosystems in Winter Symposium, 16-21 February 1990, Churchill, Manitoba, Canada.

Abstract

A large raven (Corvus corax) population was studied over two winters at Churchill, Manitoba, to determine the relationship between roost selection, wind speed, and air temperature. A preferred roost was located in the eaves of an abandoned building which provided protection from prevailing winds. Raven abundance at the preferred roost site had a positive correlation with wind speed and a negative correlation with air temperature. Overall, the number of birds roosting increased with windchill. The preferred roost site may be a critical component in the overwinter survival rate of ravens on the southwestern coast of Hudson Bay.