horse in Maryland and the Chincoteague Pony in Virginia. This distinction, made both on per-breed and per-individual basis, is sometimes a matter of disagreement. The traditional definition of a horse or a pony is based on whether the animal in question falls over or under . The equines on the island tend to be under 14.2, but have a horse phenotype. It is argued that their relatively small size is primarily due to environmental, rather than genetic conditions. The National Park Service provides information about these animals through brochures and the internet. The Maryland and Virginia horses are kept apart by fencing at the border between the two states. Though commonly called "wild," these horses had domesticated ancestors. Legend states their ancestors were survivors of a Spanish galleon that shipwrecked along the coast, and DNA evidence indicates the modern population includes the closest living descendants of Spanish horses brought to the Americas in the early 1500s. Previously, it was suggested the horses originated from late 17th century mainland owners who brought their horses to the barrier islands to avoid fencing laws and taxation. When excess numbers are removed from the island and they are placed into human ownership, they adapt quickly to domestication. Made famous by Marguerite Henry in her children's book Misty of Chincoteague, the animals are popular tourist attractions and subjects for photography. The Maryland horses are owned and managed by the NPS, who have carefully followed the population over generations. In Virginia, the Chincoteague ponies are owned by the Chincoteague Volunteer Fire Company. Once a year in July, the local "salt water cowboys" round them up and sort a number of animals to be removed from the island, which are put up for auction on Pony Penning Day. To keep their numbers under control on the Maryland side, a federal contraceptive program has been in place since 1994. In Virginia, the Pony Penning Days auction keeps the horse population at levels required by agreement with the Chincoteague National Wildlife Refuge. Climate Assateague Island has a humid subtropical climate and is the only part of Maryland with the southern tip of the Delmarva peninsula in hardiness Zone 8a. Gallery References External links Assateague Island National Seashore Assateague State Park Assateague photos Philip E. Hartman papers at the University of Maryland library contain letters, reports, and publications, which document environmental activities relating to Assateague Island. Barrier islands of Maryland