Friday, July 20, 2018

What Lives On Assateague Island? - The Mammals

Lots and lots of creatures live on Assateague Island, and/or in and on the surrounding waters. Despite the often harsh conditions that occur in a coastal environment, a wide variety of animal species have managed to find a niche on, or around, Assateague, which stretches from southern Maryland to northern Virginia in the Atlantic Ocean.  Each of the island's different ecological zones provide habitat for a multitude of animals; these include birds, mammals, reptiles, amphibians and invertebrates.  Today, I'll write about the mammals - those air-breathing, warm-blooded creatures like us, who walk upon the ground or swim in the ocean.
   More than twenty-five types of mammals live in or around the island of Assateague; the most well-known are the wild ponies.  They are descendants of feral horses and ponies; the first-known being the blinded Spanish pit ponies that were ship-wrecked on the island from the galleon La Galga, and were noted in a report to Spain by the Spanish ambassador.  The people of coastal Maryland and Virginia were taxed upon ownership of livestock, and they allowed their stock to run free on Assateague to avoid payment of said taxes, and, so, the "wild ponies" of Assateague came about.  The 80-plus ponies living on the Maryland end of Virginia receive only contraceptive darts for care; the ponies in Virginia belong to the Chincoteague Volunteer Fire Company, and are kept on Assateague via a contract with the US government.  The ponies feed primarily on salt-marsh cord grass, but also consume beach grass, greenbriar, bayberry, poison ivy, and many other types of vegetation that are not in the usual horse's diet.
   Other large mammals also roam the parks (the Assateague National Seashore and the Chincoteague National Wildlife Refuge) grazing and browsing on low-lying vegetation.  They are the indigenous Virginia White-tailed deer, and the non-native Sika deer, a miniature type of Asian elk, who were introduced to Assateague in the 1920s.  On-going research is evaluating the ecological effects of Sika deer on both native vegetation communities and their effect upon other wildlife, including the native white-tailed deer.
   The other other mammals range in size from small rodents, to bats, to furry critters, to large marine mammals - including the bottlenose dolphin and several species of whale that feed in the island's offshore waters.  Besides the Atlantic bottlenose dolphin, the Atlantic white-sided dolphin, and the common dolphin are frequently seen around the island - in the ocean and in the channels and bays.
Whale sightings include the fin whale, humpback whale, pilot whale, sperm whale and right whale. Seals are occasionally seen resting on Assateague Island, also; usually sighted are the harp seal, harbor seal, and, rarely, the hooded seal.
   Red foxes build dens in sand dunes and roam the island hunting for mice, birds, insects, and berries. Opossums  and raccoons provide the important environmental service of waste removal, feeding on the island's carrion, as well as insects, larvae, berries and small rodents.  The only marsupial in North America, the opossum give birth to premature young which complete their development in a pouch on the outside of the mother's body.
   Rodents such as the meadow jumping mouse and meadow vole live in grasses bordering both salt- and freshwater wetlands.  They feed on seeds, wetland plants, and in the case of the jumping mouse, insects.  Though seldom seen, both river otters and muskrat make their home in the island's marshes and adjacent waterways.
 A listing of mammals on and around Assateague Island:
Chincoteague/Assateague ponies
Red fox
Whales - fin, humpback, pilot, right, and sperm
White-tailed deer
Bats - little brown, red, and silver-haired
Delmarva fox squirrel
Eastern cottontail rabbit
Dolphins - Atlantic bottlenose, Atlantic white-sided, and common
Sika deer (miniature Asian elk)
Mice - house, meadow jumping, and white-footed
River otter
Rats - Norway and rice
Least shrew
Virginia opossum
Meadow jumping vole
Seals - harbor, harp, and hooded

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