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New Mexico State University

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NMSU graduate helps restore mule deer population with an ongoing management plan

It’s no secret the mule deer population in most parts of the West have been experiencing dramatic fluctuations throughout the last 40 years in response to changes in their habitat.

Jana and volunteer capture deer in net.
NMSU graduate student Jana Ashling spends half of her year full-time in the field capturing, translocating and tracking mule deer. (Photo courtesy of Dan Williams, New Mexico Game and Fish)

Unlike the familiar widespread decline, Silver City, N.M., has seen a recent overabundance of deer, causing human-to-wildlife conflict in its urban environment.

New Mexico Game and Fish has implemented a deer management plan to relocate the excess deer from Silver City to other areas where deer populations have declined. James W. Cain, assistant unit leader for the New Mexico Cooperative Fish and Wildlife Research Unit and adjunct professor for New Mexico State University, along with NMSU graduate student Jana Ashling are assisting with the project by monitoring the translocated deer.

Ashling is on site full-time, studying the movements, survival rates, reproductive success and habitat preferences of the translocated deer.

“We are trying to solve a dual management problem,” Ashling said. “We’re getting some great data and going to see if translocations are an option to help bolster these declining mule deer populations.”

The project uses both soft and hard releases and will determine the level of survival rates associated with each type of release. The deer are taken from the urban conflict areas and relocated to either the San Francisco River Valley or Peloncillo Mountains, near the Arizona border. In a hard release, deer captured in Silver City are taken to one of the translocation sites and released directly out of the trailer into the wild. For the soft releases, translocated deer are placed in a pen for a short period of time prior to release into the wild.

“There are two acres in each of the two release pens for the soft releases,” Cain said, “and the deer are kept there for three weeks. The pens are surrounded by 8-foot deer fencing and an electrical hotwire to help keep predators out.”

The adult deer are outfitted with radio collars, which are used to track and monitor the deer for mortalities.

“The collars will notify researchers if the deer hasn’t moved for more than four hours, meaning it may be dead,” Cain said.

GPS collars help to determine habitat selection and are removed after one year.

“Not only is it important to put more numbers out there, but we want to know if they are producing young that can survive and eventually go on to reproduce,” Ashling said.

To help Ashling and her colleagues track birth rates, vaginal transmitters are placed inside the doe. The Vaginal Implant Transmitter comes out when the doe gives birth. Ashling will then capture and fit the fawns with ear tag transmitters and monitor survival. The VITs are typically temperature sensitive, but for the first time in this area, researchers are using photosensitive transmitters.

“The VITs we put in pregnant mule deer females emit a signal at a rate of 60 beats per minute, that signal pulse rate doubles once the vaginal transplant is expelled, allowing us to know when the fawns are born, then we can locate and capture newborn fawns,” Cain said.

At least 100 mule deer per year will be captured and translocated within the program.

Ashling spends half her year in three locations, commuting from the two sites and taking classes on the NMSU-Las Cruces campus. The other half of the year, she spends in the two locations conducting her research.

“Mule deer are my life right now,” Ashling said. “I love going to work every day.”

Ashling is a Minnesota native and attained her bachelor’s degree at South Dakota State. She has worked throughout the country on various projects, finding her passion in big game. She has hopes of someday working as a game biologist in a state department.