I like the Massachusetts story of the heaviest flying bird in North America. It has gone from valuable food source to completely extirpathted from the state, reintroduced from other states, and is now a fearless suburban pest. Wild turkeys are hunted across the region, but they have adapted to rely on human food sources, and the protections that come with living in settled areas. There's no turkey season in the town center, or at the wildlife sanctuary where I took these photos.
Imagine if the largest land mammal in North America had a similar story. Wood bison at your birdfeeder? Towering hornless rhinos nibbling at the tops of the maples and sycamores lining main street?