Katherine

How far do crows range (for food, roosting sites, whatever) each day?  I have not seen it, but there are credible reports of roosts of 250,000 birds in nearby Minneapolis in the winter, and this class mentions roosts of up to 2 million birds.  How can they find enough food, especially if/when there is heavy snow cover (making it harder to find seeds and grain on the ground) and bitterly cold temperatures (increasing the calories needed to maintain body temperature)?  Even if they share information (or follow one another to food sources), that many birds must require a lot of food!  Is there any research that sheds light on how they find enough food when they gather in such large numbers? In my yard, about 20 miles NE of Minneapolis, I have never had a large crow roost, although I do get small numbers of crows regularly throughout the year.  I have a variety of foods available for all the birds; year-round, the crows only seem interested in suet.