Although popularly known as Chincoteague ponies, the feral ponies actually live on Assateague Island. The entire Island is owned by the federal government and is split by a fence at the Maryland/Virginia state line, with a herd of around 150 ponies living on the Virginia side of the fence, and 80 on the Maryland side. The herds live on land managed by two different federal agencies with very different management strategies. Ponies from the Maryland herd, referred to in literature of the National Park Service as Assateague horses, live within Assateague Island National Seashore. They are generally treated as wild animals, given no more or less assistance than other species on the island, other than to be treated with contraceptives to prevent overpopulation. Conversely, the Virginia herd, referred to as Chincoteague ponies, lives within the Chincoteague National Wildlife Refuge but is owned by the Chincoteague Volunteer Fire Company. The Virginia ponies are treated to twice yearly veterinary inspections, which prepare them for life among the general equine population, if they are sold at auction. While only around 300 ponies live on Assateague Island, around 1,000 more live off-island, having been purchased or bred by private breeders.