"... A recurring theme among many of the grosbeaks tagged at overwintering areas in Maine, Minnesota, and Penn­sylvania is a migratory connection to areas of spruce budworm outbreak in the boreal forest. Even though they are famous for feasting on sunflower seeds in winter, many Evening Grosbeak populations key in on sources of spruce budworm larvae for the vital protein needed to lay eggs and rear young.

Another general trend among gros­beaks was illuminated by the plight of #228, a bird Yeany tagged in the winter of 2022 in Maine. By summer #228 was almost 250 miles to the northeast, spending the summertime in a spruce forest in far eastern Quebec. The follow­ing winter, #228 was recorded almost 1,000 miles back to the west along the shore of Lake Huron, where he met his demise—a victim of a window collision at a home with a backyard bird feeder.

According to biologist Stephanie Egger at the U.S. Geological Survey Bird Banding Laboratory, Evening Grosbeak is the most reported species among reports of banded birds that died from flying into windows. Young says grosbeaks 'seem to be susceptible to window kills, because they’re social and they flock at feeders'—which means they are often attracted to backyards near residential structures, which puts them flying near ground level among deadly glassy mirages..."