Nature Notes; Mule Deer Movers: The Art and Science of Mule Deer Relocation

Mule Deer Movers: The Art and Science of Mule Deer Relocation

It’s a cold February morning at Elephant Mountain Wildlife Management Area, 25 miles south of Alpine. A 30-person crew stands at attention at headquarters.

From the slopes of the mountain – a retort, like a gunshot. Then, a helicopter appears overhead – and gently places two mule deer does on the ground.

The crew swings into action – giving antibiotic shots, taking blood samples, recording data. Within minutes, the deer – dazed, but placid – are loaded in a Texas Parks & Wildlife trailer. By day’s end, they’ll have a new home.

Mule deer capture is its own kind of rodeo. Here, it’s designed to help struggling deer herds in the Big Bend.

In February 2016, Texas Parks and Wildlife, in cooperation with Alpine’s Borderlands Research Institute and others, captured about 80 deer at three locations. From two private ranches and Elephant Mountain, deer were relocated to Black Gap Wildlife Management Area and the adjacent El Carmen Land & Conservation property.

Shawn Gray is mule deer program leader for parks and wildlife.

“The main goal of this project is to really help boost a mule deer population that’s needed some help for some time now,” Gray said. “We wanted to add more animals to the population, to help reverse that trend, make it an upwards trend.”

Deer numbers declined during the droughts of the late 1990s and the one that began in 2011. Now, populations in most of the Trans-Pecos are rebounding strongly. But on both sides of the Rio Grande, especially from Big Bend National Park to Black Gap, they have not regained their numbers.

Black Gap has sufficient forage to sustain 800 to 1,000 deer, Gray says. But in 2014, the population was barely 300.

Gray led the first relocation in 2015 – moving 40 deer to Black Gap and the El Carmen land.

“The country that we’re trying to boost the population in is very vast,” Gray said. “It’s really just not those two properties – we want to do this at a landscape level, in Texas, and even Mexico. It’s a pretty big project, and so far the initial stages of the project has been pretty successful.”

In the first relocation, 70 percent of the deer survived. The remainder mostly fell prey to mountain lions. In February, does are in the early stages of pregnancy. Most will give birth to twins in early summer – a “three-for-one deal,” Gray says.

The capture requires a range of expertise. Quicksilver Air provides the helicopter service. With bases in Alaska and Colorado, the company specializes in wildlife capture. From the chopper, a gunner fires a net over a deer. A “mugger” drops down, blindfolds and hobbles the doe and places it in a sling.

Dr. Bob Dittmar, of parks and wildlife, is the project’s lead veterinarian. He said the deers’ health and safety is a top priority.

“Obviously there’s this weird bird that drops out of the air, chases them around a little bit,” Dittmar said. “Then they get netted and a blindfold put on them, their legs tied together and put in a bag and dropped in here. It’s kind of like being abducted by aliens. So we try to reduce that [stress] as much as possible.”

Captured deer are placed on tables. The crew monitors their temperatures, to make sure they don’t overheat. Blood samples are collected. Deer receive antibiotic and anti-worm medication, and each doe receives a numbered ear tag.

The crew attaches radio collars and GPS devices to some of the deer. The data will shed light not only on the success of the relocation, but on deer ecology in Big Bend, Gray said.

“We’ll be able to really determine survivability – and if they do succumb to mortality, why,” Gray said “Some of those radio collars have GPS capability – so we’re looking at travel corridors, habitat usage, that type of thing.”

The wildlife managers are testing the effects of a “hard” versus a “soft” release. In a hard release, deer are turned out directly into a vast property. In the soft release at Black Gap, they’re first kept in a 400-acre enclosure for several weeks. Biologists think the soft release may help the animals adjust to the move.

The Elephant Mountain capture concludes shortly after noon. Two hours and 120 miles later, the does are released at Black Gap.

In the coming months, biologists hope, these newcomers will join a herd that needs reinforcements.

Nature Notes is underwritten by the Dixon Water Foundation and is produced by Marfa Public Radio in cooperation with the Sibley Nature Center in Midland, Texas. The program airs on 93.5 FM, KRTS Marfa, Tuesdays and Thursday at 7:45 a.m. and 4:45 p.m., Central time. This episode was written by Andrew Stuart.