Friday, November 5, 2010

Elk In The Bosque Del Apache

By Rebecca Rose

Acres and acres of trees, a plentiful supply of food and water and no predators in sight:  At the Bosque Del Apache, it’s good to be an elk. 
And that’s just the dilemma wildlife officials are having.  
A noticeable rise in the elk population at the Bosque Del Apache National Wildlife Refuge has prompted officials to launch a three year study, to best understand how to manage their growing numbers.   The study, aimed at examining migratory patterns, eating habits and health issues of the elk, began last week. 
U.S. Fish and Wildlife Biologist John Vradenburg is part of the team leading the study.  He estimates that at least 80 elk now call the refuge home. Vrandenburg spoke at a press conference last week, detailing the specifics of a plan to use helicopters to fly in to the refuge to dart and tag at least 30 of the elk. “Presumably, 99% of them are in managed parts of the refuge.” he said. 
There is no management plan in place for the elk, who have found a comfortable, safe home amidst the refuge’s bountiful land. While the Bosque Del Apache was founded as a refuge for birds, its overall mission remains to ensure a habitat for all species that depend on it for survival.  Officials want to study what impact the elk have on the refuge and develop a long term plan for managing them.
The elk are already having some apparent impact.  Over a million pounds of corn are produced annually at the refuge, to feed the tens of thousands of migratory birds that call the Bosque Del Apache home. The elk are foraging on the corn they find, and often trampling stalks as well. “We’ve lost about 30 acres of corn to the elk already.” said Vradenburg.    
In the 1930s, when the Bosque Del Apache was founded, there were no elk on the land.  Between the 1980s and 1990s, there were isolated sightings and reports of small groups.  Then, over the past 10 years, their numbers began to multiply. Vradenburg estimated there at least three distinct herds roaming across the refuge today.
Normally, officials would look to other parks or refuges to take their cues for how to handle the population growth, but the situation at Bosque Del Apache is wholly unique. Officials have the difficult task of trying to conduct their study without disrupting the migratory patterns of the refuge’s avian residents. That includes flying a helicopter during peak population times.
“The refuge will not do anything that compromises the migratory pattern of the birds,” Vradenburg said.  “But the opportunity to fly [from a helicopter] is dwindling.  There are not that many birds on the refuge right now.”  Should officials miss the chance to dart and collar the elk by way of helicopter, the next step is to use live baiting on the ground.
To fire the tranquilizer dart accurately, crews need to get within at least 30 ft, making it a precise mission. The dart is air driven; pressure pushes the drug into the bloodstream. This procedure is considered to be the most humane, according to Vrandenburg.  Once drugged, the elk is unconscious for 30-45 minutes, at which time the collar can be applied by crews on the ground.  The crews then administer a “reversal”, a drug to wake the animal.  
The collar is designed to last for 3 years. Each one has a distinctive signal.  When it expires, a charge ignites, similar to a .22 caliber gunshot, and discharges itself from the animal’s neck.  Collars are also equipped with a “mortality signal” that immediately emits out a beacon should the animal expire prematurely.  After they have been collared, government researchers, aided by refuge staff and a team of volunteers will spend a year tracking the elk, studying their habits and conducting a more concise population count.
New Mexico Game and Fish has also partnered with the federal agency on the project, to study a possible outbreak of Chronic Wasting Disease, a neurological disease similar to mad cow disease in cattle.  While there have been no confirmed cases of human infection, state officials want to keep a close eye on the disease.

For more information on the Bosque Del Apache, visit

No comments:

Post a Comment