Historically restricted to the western half of this continent, Evening Grosbeaks have expanded eastward thanks to the food they found here. Evening Grosbeaks are large finches, and like other finches will often have irruptions in winter, meaning they’ll leave their typical range when food is scarce. Thanks to the abundance of (unfortunately non-native) Box Elder and cyclically abundant Spruce Budworm, these grosbeaks have established themselves in the east and have become a colorful visitor to our yards and feeders in the winter. Despite the damage that Spruce Budworms do to trees, they are a native insect and an important food source for grosbeaks and a number of other species that nest in the boreal forest. It was during the budworm’s last outbreak, in the ’80s, that we recorded an Evening Grosbeak population boom, though numbers have dwindled since. More recently, budworm abundance has been increasing and it’ll be fun to see if the large black, white, and yellow Evening Grosbeaks become common around our yards again.
Backyard Bird of the Month is a feature by Maine Audubon created for the Maine Home Garden News, the newsletter of the University of Maine Cooperative Extension: Garden and Yard
Photo by Doug Hitchcox