I was focused on taking pictures of a Brown Thrasher when this big guy came lumbering across my yard. It's a Groundhog, aka woodchuck, land-beaver, or whistle-pig. It's a rodent, a big honkin' rodent, that is in the squirrel family.
I'd never seen one in the yard before and wonder if the warm, dry summer has spread them further out in search of food. Another possibility is that a first-year male set out in search of new territory outside of dad's territory.
Groundhogs are mostly herbivores, so I don't have to worry about him bothering the birds. Groundhogs themselves can fall prey to coyotes, foxes, bears, large hawks, and dogs.
Besides eating grasses and other vegetation, they'll also eat insects. When I observed him, he ate mostly greens from my yard and didn't seem too interested in seed fallen to the ground.
He's likely beefing up for hibernation. After the first frost (which could occur this month), they'll tuck themselves into a burrow below the frost line and won't emerge until March or April. Or maybe we'll see him in early February for his annual spring prognostication!