Utah Division of Wildlife biologists are surprised at the level of mule deer survival this spring in the Northeast Region.
Earlier this spring UDWR Northeast Region Wildlife Biologist Clint Sampson was concerned about the potential for a big deer die off due to prolonged drought and poor condition of animals heading into last winter. Deer that were trapped and checked late last fall showed low levels of rump fat and many showed body conditions that were below optimal.
“I expected to see more mortality but it’s not as severe as I expected it to be,” Sampson said. “Luckily this spring has been incredible with one rainstorm after another. Range conditions right now are night and day compared to last year.”
Sometimes deer that go into winter in poor condition have a hard time rebounding after a long winter. Once they become emaciated, their gut bacteria gets depleted and they can starve to death even though there are plenty of fresh spring plants for them to eat, Sampson said.
An important part of the Utah Migration Initiative is collaring big game animals, collecting population data and spotting trends. Biologists have noted low fawn survival numbers in recent years and a below average percentage of pregnant cow elk in the Book Cliffs. Population studies using global positioning sensor (GPS) collars on animals have allowed them to spot and begin to monitor these trends.
“With the Book Cliffs, it’s a limited entry unit and it’s a high priority to sportsmen,” Sampson said. “They are investing 12 to 13 years to draw a rifle deer tag and close to 18 years for a rifle elk tag. We hope this Migration Initiative helps us become better stewards.”
Regarding the Utah Migration Initiative, Sampson said collaring animals is helping them learn a lot about mortality, predator / prey relationships, animal movement from summer to winter range, and how big game populations here compare to other parts of Utah.
In addition, Sampson said BYU students have placed well over 100 trail cameras in the Book Cliffs. The cameras will collect important data about how all of the animals, including feral horses and cattle, interact with big game animals.
Over the past few weeks Sampson and a crew of UDWR employees, Brigham Young University students and other volunteers have been camped out in the Book Cliffs waiting for elk calves and mule deer fawns to start hitting the ground. Earlier this spring they captured several cow elk and mule deer does. Those animals were implanted with transmitters. The transmitter is placed in the animal’s birth canal and when it’s baby is born the transmitter falls out on the ground. That transmitter then sends a signal showing a temperature change.
Early every morning Daniel Sallee, a BYU graduate student and his helpers check for transmitter signals. If they have a signal they track down the fawns, take some quick measurements and fit them with collars. Mule deer normally have two fawns.
They also locate newborn fawns and elk calves, whose mothers are not collared, by meticulously combing likely-looking terrain with binoculars. They watch for deer and elk that leave the herd. When the babies are newborn they produce almost no scent, but their only other defense is to lie still. They aren’t strong enough to run away until they have nursed for a day or two. This is when many are lost to predators. Bears are known to be particularly adept at locating newborn calves and fawns.
The biologists wear latex gloves and try to spend no more than five minutes weighing the animals and fitting them with collars. They want to be careful not to contribute to fawn or calf mortality.
This is the second year for this study in the Book Cliffs, but Sampson said there are similar efforts going on statewide. The goal is to collar 40 mule deer does and 40 cow elk in the Book Cliffs. Presently there are hundreds of animals wearing GPS collars in Utah, including moose, mountain goats, pronghorn, black bear and mountain lions. The Migration Initiative is currently in its fifth year on the South Slope of the Uinta Mountains. Sampson said Wyoming was the first state to begin to monitor big game migration patters this way.
“The Migration Initiative is funded with sportsmen’s dollars,” he said. “We work closely with the Rocky Mountain Elk Foundation, Mule Deer Foundation, Sportsmen for Fish and Wildlife, BYU, Utah Sate University and others. It’s a big, collaborative effort.”