Alaska island's 29 reindeer multiplied, then ate themselves to extinction

Twenty-nine reindeer introduced to St. Matthew Island in 1944 grew to over 6,000 animals. This population boom led to severe overgrazing of the island's lichen food sources. An extreme winter in 1963-1964 brought devastating blizzards and deep snow. These harsh conditions prevented reindeer from accessing their depleted food supplies. Ultimately, the entire reindeer herd perished, leaving the island devoid of these animals.