This isn't the first time this has happened. The eastern peregrine falcon was supposed to be extinct although there were confirmed reports of that peregrine all the way up until 1980. A known wild produced male bred with a released falcon in 1980 and a pair of unbanded birds produced young that same year in Maine. Anyway to make a long story short about 7 subspecies of peregrine were released east of the 100th meridian. The idea was to throw them all together and let nature sort it out. The birds were very successful and have recovered to be delisted in 1998 by the feds. Sadly some states still carry them on their endangered lists.
So far as I know there hasn't been any problems with those birds. They eat a bunch of stuff we'd rather not have such as pigeons and starlings but the facts are the Feds and others released different subspecies of peregrine falcons in the east when they could have waited longer and allowed the Canadian and Western US captive populations of peregrines to begin to produce enough birds to begin releases a few years later. West of the 100th meridian there were populations of peregrines so it was agreed upon to release only birds from that subspecies. For the life of me I can't figure out how the birds could tell where the 100th is. So far as I'm concerned it's water over the dam but I thought I'd bring it up. To so many a peregrine is a peregrine and that's that.
I wonder if the Feds have done this more than a couple of times. Florida panthers? Red wolves? Others?