We’re on Assateague Island, off the coast of Virginia and Maryland, listening to the sounds of wild horses as they feed on grass. No one knows exactly how or when these animals came to Assateague- but since their arrival, the horses have thrived, but they’re threatening the habitats of other island species. I’m Jim Metzner, and this is the Pulse of the Planet, presented by the American Museum of Natural History.
“Assateague Island is home to lots of native species that depend on this critical barrier island habitat which is relatively rare and what we’ve found so far is that the horses are having a negative impact on that habitat.”
David Powell is a Principal Investigator with the Earthwatch Institute.
“With vegetation studies we know that they’re eating more grass than the island produces each year. They’re overgrazing and they also trample the dunes which are a critical habitat for some birds that breed there.”
In order to save those habitats on which plovers and other island species depend, scientists are hoping to regulate horse populations by administering birth control. The question is, how will the wild horses react to the change in their breeding cycle?
“Coming in May and June, females are breeding; stallions are defending their groups a lot more vigorously and they’ll continue to breed until the mares get pregnant. We don’t know yet whether or not contraception has effects as far as disrupting the group, causing more aggression or maybe making the whole social organization break down because the mares aren’t breeding.”
Pulse of the Planet is presented by the American Museum of Natural History. Additional funding for this series has been provided by the National Science Foundation. I’m Jim Metzner.