Sunday, November 07, 2010
Known for Its Bird-Watching, Bosque del Apache Now Has As Many As 100 Elk
By John Fleck
Journal Staff Writer
The elk have found the Bosque del Apache.
"Fifteen years ago they were very uncommon, and now they're very common," said John Vradenburg, a U.S. Fish and Wildlife Service biologist at the wildlife refuge south of Socorro.
Vradenburg and his colleagues, working with scientists from the New Mexico Department of Game and Fish, have begun a project to track and study the growing herds at the famed bird refuge south of Socorro.
With no firm data, Vradenburg said estimates of the Bosque del Apache's elk population range from as few as 30 to as many as 100. But to try to clarify how many there are, Vradenburg and state biologists have begun capturing elk and attaching radio tracking collars so the scientists can get a better idea of what the big creatures are up to.
As of late last week, the researchers had captured and collared 14, and they hope to expand that number to 30, Vradenburg said.
They shoot the elk with a tranquilizer dart, attach the collar and also gather data on the animals' health. In particular, they are trying out a new test for signs of chronic wasting disease, a fatal malady afflicting deer and elk in parts of New Mexico, said state Game and Fish biologist Kerry Mower.
Elk are best known today as creatures of the mountains of New Mexico. Before humans reshaped the landscape in recent centuries, however, they were primarily creatures of the plains, spending their lives grazing.
With most big predators gone, they have expanded into other habitats because of their ability to live on a wide variety of plants, according to Mower. For example, a recent study by New Mexico State University scientists found a herd of elk settling into the area around Chaco Canyon National Historical Park in northwestern New Mexico, a high desert ecosystem once thought unsuitable for the animals.
At the Bosque del Apache National Wildlife Refuge, three distinct herds seem to have become established in recent years, according to Vradenburg. One lives in the northern part of the refuge, one in the center and one in the southern part.
Visitors driving the refuge's southern bird-watching loop frequently see elk in recently cleared farm areas, he said.
The refuge has always had a resident deer population. But routine surveys rarely turned up any elk until recent years, Vradenburg said. In past years, as many as 300 to 500 deer are believed to have lived on the refuge. That has dropped in recent years, but the deer population appears to be rebounding, he said.
Mower said it is especially important to monitor for chronic wasting disease in a place like the Bosque del Apache. The disease spreads especially well in herds that live in close proximity to one another, which happens at places like the Bosque del Apache where food is abundant and threats are few.
Vradenburg speculated that the growing elk population has arrived by way of the Rio Grande corridor, which serves as a natural travel route for animals of all sorts.
"It's the main corridor for anything from a hummingbird to an elk," he said.