I suspect that most of the folks that have a black walnut tree growing in their yards enjoy the tasty nuts the trees bears, its yellow fall foliage, and attractive shape. However, whenever I tell folks that their black walnut tree is also valuable to wildlife, they are pleasantly surprised.
The tree serves as a host the banded hairstreak butterfly and more than 100 moths including the luna, royal and imperial.
A number of small mammals eat the nuts including the eastern chipmunk and both gray and fox squirrels. In fact, black walnuts can comprise up to 10 percent of the fox squirrel’s diet.
Whenever black walnuts are cracked open by mammals, or crushed by vehicles in driveways or highways, many birds eat the highly nutritious meat. In fact, black walnut meat is ranked as a choice food for the eastern towhee, cardinal, white-throated sparrow, brown-headed nuthatch, Carolina chickadee, tufted titmouse, blue jay, and woodpeckers (hairy, red-bellied and downy).