Eagles will eat just about anything they physically can so probably lots of squirrels, rabbits, smaller possums and raccoons but also eagles will sometimes eat carrion so I could certainly imagine they sometimes get this off something like a deer carcass.

People still use lead target shells all the time

Ungulates and rodents, mostly.

Birdshot is only banned for migratory bird hunting. Many landowners shoot woodchucks with rifles because they dig holes that livestock step in and break their legs, also the holes cause problems with equipment - they most often use lead bullets and leave the carcasses for the wildlife to dispose of. Some have switched to green ammunition but few have. We need to raise awareness for the need to switch to non-toxic ammunition. Maybe a bill that subsidies green ammunition with a small tax on lead ammunition could help.