From The Atlantic:
Isle Royale is 200 square miles of land in the watery expanse of Lake Superior. One cold winter 70 years ago, wolves came over an ice bridge and settled into a largely isolated island existence. Unfortunately, island life has not been good for them.
By 2016, the number of wolves on Isle Royale declined from a peak of 50 to just two, a male and a female. As a result of inbreeding, they were half-siblings as well as father and daughter. They had a pup together that lived less than a year. Even before that, scientists were finding wolves on Isle Royale with crooked spines and extra ribs.