Nevada Tracks Deer with GPS Collars
Nevada's mule deer herds may start developing paranoia, believing that someone is watching and tracking their every move. In this case, they would be right.
Over the winter the Nevada Department of Wildlife began monitoring a new radio collar that contains a small GPS unit that generates coordinates of the animal every four hours and a transmitter to transmit the data via satellites to NDOW computers each day.
"Concern for the western Elko County deer herd's critical wintering areas, especially after the 2006 catastrophic wildfires, prompted an effort to intensively monitor mule deer movements and their survival using satellite telemetry in real time," said NDOW Wildlife Staff Specialist Mike Cox.
NDOW big game biologists captured 10 mule deer in December of 2006 from specific subherds in the Bull Run, Independence, and Tuscaroa mountain ranges where the deer spend the summer. Cox reports that each subherd has a history of complex migration routes that they take from summer habitats to critical winter ranges, including suspected movements to Idaho.
The devastating fires in Area Six, a hunt unit in Elko County, also provided an opportunity to evaluate how deer maneuvered through the area and wintered in response to these massive burns.
NDOW biologist Ken Gray states the new satellite collars have been in the plans for quite some time. "For several years we have wanted to conduct seasonal habitat delineation projects to determine how far into Idaho Nevada's deer are going to winter. We wanted to know where deer are wintering so that we could provide input on habitat related issues impacting important deer habitat."
Cox reports the objective of the project is to better understand specific staging areas and routes the deer use to migrate across the landscape. The collars proved even more valuable after last year’s devastating fires which destroyed large chunks of their historic winter range. NDOW was able to evaluate how deer would maneuver through the various burns and survive the loss of habitat. This information has helped NDOW and land management agencies better focus limited habitat restoration and conservation funds on specific areas the deer prefer based on the GPS coordinates collected each day.
"The real benefit is having continuous data recorded every four hours. We can track exactly how the deer move from point A to point B, and discover what obstacles they might have encountered, everything from mining activity to highways. With a conventional VHF collar, we could only track by the air or on foot every one to two months and get a far less detailed idea of how there were moving," said Gray.
"As much as biologists would like to spend time in the field collecting the data the old fashioned way on foot, there are only 15 NDOW game management biologists statewide, and with ever increasing responsibilities, there simply is not enough time to collect such detailed information," says Cox. "Even if an army of volunteers was available, there are too few roads in many of the critical areas to track hourly herd movements. With large movements made at night by some of the marked deer, even aircraft with a radio receiver are impracticable for documenting the detailed activity collected with the satellite collars."
Gray reports that this winter was especially hard on the Area Six fawn population due to the enormous acreage of habitat lost to fire.
"One of the real tragedies of this past winter was that we lost around 50 percent of the fawns, and this was not a particularly difficult winter. With the satellite collars, we could see exactly what route does led their fawns. Some traveled through as much as 50 miles of burnt habitat to reach their winter range and while the adults had sufficient energy reserves to cross, the fawns did not."
Gray points to several benefits of the new collars. He states that although it has not happened yet, when one of the tagged deer dies, NDOW will know much sooner than in the past, allowing for biologists to go out into the field and discover the reason. When the deer begin to fawn, their movement becomes very limited and biologists will see this and be able to research what the real attributes for this selected habitat are. Biologists have found that with every question answered with these new satellite collars, new questions seem to arise.
"We have learned a great deal over this past year. The difference in some of the paths these deer take is remarkable. We’ve had a couple of deer that have moved no more than five miles, and one that has traveled from Interstate 80 all the way to the Nevada-Idaho line, about 90 miles away. One deer went approximately 30 miles to her winter range, when there was good winter range only five miles in another direction. It's our job to try and figure out why she bypassed a suitable range to go to one much farther away," said Gray.
The Nevada Department of Wildlife (NDOW) protects, restores and manages fish and wildlife, promotes fishing, hunting, and boating safety. NDOW's wildlife and habitat conservation efforts are primarily funded by sportsmen’s license and conservation fees and a federal surcharge on hunting and fishing gear. Support wildlife and habitat conservation in Nevada by purchasing a hunting, fishing, or combination license. For more information, visit www.ndow.org.