Farm fields sown with corn and grains are favoured after the harvest. Garbage landfills have been particularly important in providing a winter food source. This close association with humans and the attendant ease of acquiring food, particularly through the winter months, has likely contributed to the increase in the populations of the Northwestern Crow in urban areas. An analysis of Christmas Bird Counts for the period 1975 to 1994 in select areas of southwestern coastal British Columbia indicates that the larger cities attract more crows in winter than do smaller cities and rural sites, and that agricultural areas are also important foraging sites, where this crow uses seasonally available food sources such as fruit and grain. The Northwestern Crow is not normally considered migratory in British Columbia, but local movements appear to be widespread.
Birds move from exposed coasts to more protected areas in autumn.
With the coming of spring, winter flocks disperse, and areas of coastline that were almost without crows during the winter receive their courting pairs. Total numbers of crows reported from the Georgia Depression illustrate this point. They average about 30,000 birds from September through March, then drop to an average of about 7,000 birds from April through August. This difference can be only partly attributed to flocking behaviour during the non-breeding season. Behaviour important to the Northwestern Crow during the non-breeding season is its congregation into large flocks that move between feeding areas and roosting sites.