28 November 2022
Though they breed in the arctic around the world, the North American population stays west of the Mississippi. These geese are rare in Pennsylvania.
Their “greater” and “white-fronted” adjectives don’t make much sense unless you know the species they resemble in Europe.
They are “greater” because they are larger than the lesser white-fronted goose (Anser erythropus) that occurs only in Eurasia and is now Vulnerable to extinction.
They are “white-fronted” because they have white feathers on their faces surrounding their beaks, a field mark that distinguishes them from the similar greylag goose (Anser anser), another Eurasian species.
Only a handful of greater white-fronted geese are seen in western Pennsylvania in any given year, and then only in late October through early March.
If you see a goose that resembles this one check its field marks carefully. It may be an odd domestic goose, described here:
(images from Wikimedia Commons, map embedded from allaboutbirds.org)