Names are so confusing!

This bird looks like a house sparrow (Passer domesticus) but he’s not.  He’s a Eurasian tree sparrow and he’s the reason why our tree sparrows are called American tree sparrows.

Eurasian tree sparrows (Passer montanus) are native to Europe and Asia (of course) but about 15,000 of them live in the St. Louis area now.  In the 1870’s, 12 were imported from Germany and established a breeding population but they were never as successful as their aggressive cousins.

Passer montanus is 10% smaller than a house sparrow, has a brown (not gray) head, and a black ear patch.  Males and females look alike and the juveniles are just duller versions of the same.

Eurasian tree sparrows are doubly misnamed.  They nest in holes in buildings, not in trees, and they don’t live in the mountains but they have “tree” and “montanus” in their names.  That’s because house sparrows dominate the cities of Europe and pushed this sparrow to live in the open countryside where there are trees.  In Asia the “tree” sparrow lives in cities.

American tree sparrows are misnamed, too.  European settlers thought Spizella arborea resembled the Eurasian tree sparrow so they called ours “American tree sparrows” even though ours spend the winter in scrubby places, not trees, and breed and forage on the ground.

Do you think the American tree sparrow below looks like the Eurasian one above?  I don’t.

Alas, they are all misnamed.

(photos from Wikimedia Commons. Click on the images to see the originals)