It’s 8:12 a.m. June 9 on the western slope of the Wyoming Range Mountains. The report from University of Wyoming PhD student, Melinda Nelson, that 10 Vaginal Implant Transmitters (VIT) have been dropped, means a possible 20 fawns to find, test, and collar. Without haste Nelson phones the VIT locations to project leader Dr. Kevin Monteith from the UW Cooperative Fish and Wildlife Research Unit. Monteith and his research team in the field consisting of representatives from Bureau of Land Management, Wyoming Game and Fish Department and the Muley Fanatic Foundation begin their trek to a location on the eastern slope of the mountains near La Barge. Once in the vicinity, Monteith extends the antenna high in the air to the radio transmitter to find a more accurate location of the VIT and momma’s collar, which was placed on her in Phase One of the project approximately three years ago.
An hour later, VIT is located on a birthing site and within 20 minutes two mule deer fawns located. Unfortunately, the two fawns are deceased and predicted stillborn.
“While I realize it’s part of nature, it was still sad to see them dead,” Joey Faigl, Muley Fanatic Foundation, said. “I just stared at the two precious fawns and asked myself, why? What’s causing this?”
This is a question researchers hope to find out, to discover the reason for the loss of fawns and the cause of declining mule deer populations in western Wyoming. Iconic herds of tens of thousands two decades ago, now struggling to remain stabilized.
“It’s accepted that if we want to grow more mule deer, we need to grow more fawns,” Monteith said, “Hence the focus on those little guys.”
The University of Wyoming Cooperative Fish and Wildlife Unit and Dr. Monteith are in the middle of one of the largest mule deer studies ever completed in Wyoming. Monteith already has measured the mom’s health, part of Phase One of the Wyoming Range Mule Deer Initiative project, which began in 2010, now in Phase Two, looking at the fawn survival. The roughly $1.5 million study has been supported by Wyoming Wildlife and Natural Resource Trust, Muley Fanatic Foundation, Animal Damage Management Board, Wyoming Game and Fish Department and Bowhunters of Wyoming.
The decline of mule deer populations’ decades ago has been blamed on many possible factors; poor plant conditions resulting in less food, predators, overhunting, and shortage of habitat. Monteith and many of the researchers know the true answers can only be found through science.
“I think the idea of having the various data sets relative to fawn survival is critical,” Joshua Coursey, president and CEO of the Muley Fanatics Foundation, said. “Those data sets look as if fawns live or die, and if they die, what are the reasons? If its changes in the nutritional carrying capacity of the landscape or predation we now have the science behind it. We need to remove the guesswork.”
In the last two years of the study, researcher’s spent time studying adult female mule deer migrations, and nutritional dynamics.
Phase One of the project will help identify mule deer response to oil and gas development, migration corridors between winter and summer ranges, and how many mule deer the habitat can support.
“Phase Two is to really separate and identify the relative roles of habitat, nutrition and predation on fawn survival and cause of mortality,” says Monteith.
Researchers knew pregnancy rates are high, but need to discover why fawn recruitment is low. During spring captures of the adult females, the results of an ultra sound discovered that most females carry twin fawns, but the number of fawns that survive to December drops by more than half.
During the spring captures, Monteith and his crews implanted the tiny transmitters into the female’s birth canals and in June the transmitters fall out giving off a signal. The signals are tracked by many teams and the tromping begins through the high Wyoming Range Mountains.
“I was good at immediately finding the VIT at the birth site, but finding the fawns was a task to be had,” Faigl said.
Once the fawns were found, the teams wash their hands with the surrounding sagebrush prior to handling the one day old fawns. The study begins with measurements, weight, retrieving blood and finally a small elastic tracking collar is applied around the neck of the fawn.
Throughout the summer the fawns will be tracked. When the collar has remained motionless for six hours, the signal changes to indicate mortality. When this occurs, the researchers will find the deceased fawn and determine cause of death. This process is known as the fawn’s version of “CSI.”
If the number of fawns killed by black bears, coyotes, or mountain lions is recorded, this won’t exactly be the true story of why the mule deer populations are declining. The support of the habitat quality, food conditions, weather, and other variables will be combined with predators and used to determine the underlying role of each. In most scenarios, female deer attempt to rear more young than is possible given nutrition and habitat conditions, therefore it is critical to understand what is physiologically possible given the capacity of available resources. When predators kill more fawns than what would be lost otherwise in their absence, they begin to play an important role in limiting survival and recruitment of young.
Gary Fralick, Wyoming Game and Fish Wildlife Biologist based out of Thayne and Big Piney, knows taking in account of all the deer’s life aspects, will help wildlife managers such as the WGF Department better manage this herd and many other herds.
“If predation is limiting fawn survival, or is having a great impact on fawn survival, then we need to know and understand which species of predator, whether coyotes, mountain lions or black bears might be having the greatest impact. The department then may consider adjusting hunting seasons for those species,” Fralick said. “On the other hand, if we are finding fawns that are in poor conditions because perhaps the does weren’t able to produce sufficient milk to nourish them, we can figure out what to do in the birth sites to improve forage available to females.”
“The experience of the fawn study has been tremendous. The time and effort these UW students and scientists put forth for this ungulate species and their passion for them is unbelievable, I can’t thank them enough,” Faigl added.
This on the ground research aims to discover the reasons behind our struggling mule deer populations and what might be done to help bolster them, which in turn help NGOs and agencies focus on conservation efforts that are supported by science to benefit mule deer. The hope is that with subsequent informed conservation efforts that within many of our living years, we may see stabilized or increasing numbers of this western icon.
The Muley Fanatic Foundation, the UW Cooperative Fish and Wildlife Research Unit, and the Wyoming Game and Fish Department is about to launch a similar project south of Rock Springs, Wyoming. The Deer, Elk, Ecology Research (D.E.E.R.) project will investigate factors regulating growth and distribution of mule deer in a high-desert ecosystem.
The project will include collaring of adult and newborn mule deer and adult elk to develop an understanding of population dynamics and interactions of both species.
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