A stallion stands watch over a marsh in the Chincoteague National Wildlife Refuge in Virginia. About 300 wild — technically feral — Chincoteague ponies (Equus caballus), also known as Assateague horses, roam the island on the Atlantic coast. There is some dispute as to how the ponies ended up on the island. Some researchers believe the ponies are survivors of the wreck of a Spanish galleon, La Galga, which sank just off the coast in 1750; the U.S. Fish and Wildlife Service believes they are descendants of horses owned by early colonial settlers.