Every August, biologists take to the skies above the Nebraska Panhandle in search of bands of pronghorn. The goal of the aerial survey is to obtain a population estimate of the fastest mammal in North America, commonly (and errantly) referred to as antelope.
Pronghorn can motor. They’ve been clocked running over 60 mph. Whether they’re sprinting at state highway speeds, running for several miles at a 40-mph clip or taking a break from all that loping, their movements in the Panhandle are not well understood, said Andrew Little, landscape and habitat management ecologist with the University of Nebraska–Lincoln’s School of Natural Resources.
So this February, researchers began a two-year study designed to provide a more detailed picture of pronghorn ecology in western Nebraska.
Using GPS collars, 80 pronghorn are being tracked across the Panhandle and surrounding regions. Little said the project aims to identify the species’ critical ranges, temporal and spatial distribution, habitat use, migration corridors and survival in western Nebraska.
The project is a collaboration between researchers in the School of Natural Resources, the University of Nebraska at Kearney, the Nebraska Game and Parks Commission and more than 300 private landowners.
Luke Meduna, big game program manager with Game and Parks, which provided $175,000 in grant funding for the study, said learning more about the migration patterns is of particular interest in the Panhandle.
As agricultural production has intensified in the Great Plains, the reshaping of the land has led to more areas being fenced in. And for all their speed, pronghorn do not commonly jump fences, but rather crawl under them. Researchers have said that eons of having little to jump over on open range led to this seemingly peculiar behavior. Low barbed wire on rangeland fences have led pronghorn to either injure themselves or travel elsewhere altogether. Little said knowing more about where, when and how they move across the land could reveal corridors they frequently travel across in the Sandhills and inform land-management decisions.
“We see large winter concentrations of pronghorn in several areas in the state, particularly around the perimeter of the Sandhills and southern Panhandle, that aren’t there during our August survey period,” Meduna said. “I want to know where they are coming from and what role those agricultural lands play in their annual movements. I also want to have a better understanding of what issues our pronghorn face, and that includes both barriers to movement, but also their survival rates. How do our pronghorn compare to other herds across the West?”
Added Little: “They’re such a unique species that deserves the research to better understand how to improve management for them. This study can provide information on where these animals are at, and what barriers on the landscape potentially prevent them from getting from point A to point B because of that intensification.”
The aerial surveys, Little said, have been helpful in providing information about pronghorn population density, but there are often significant variations in winter concentrations across the Panhandle. Some mild winters see minor concentrations, while severe winters can see concentrations of several hundred pronghorn.
“Pronghorn don’t magically appear,” Little said. “They have to come from somewhere.”
Dustin Ranglack, UNK wildlife ecologist and the co-principal investigator along with Little, said the research has the potential to help build better management plans to account for what is learned about their movement.
“Understanding pronghorn movements and habitat selection is important, but how we apply that knowledge is what really gets me excited,” he said. “I know that pronghorn are not very popular with many landowners in the Sandhills, so how can we use what we learn to reduce those conflicts?”
It has been about 20 years since Nebraska pronghorn were last collared by researchers to better understand the species. Those tracking devices were very high frequency (VHF) collars. They provided some general information about their movement, and the location data had to be collected manually by researchers.
The GPS collars being used in the current study will provide much more detail, Little said.
“We’ll be able to get somewhere close to a 10- to 20-meter accuracy of a location where that animal is,” Little said. “Those locations are going to be collected on an average of about every 2.5 hours for every one of those animals. So we will be able to get some fine-scale data throughout the day and also throughout the seasons, and really provide a picture of where the pronghorn are in the winter versus the spring versus the summer and the fall.”
The research is being conducted across three hunting units of the Nebraska Panhandle — Banner South, Box Butte East and Garden — that were recommended by Nebraska Game and Parks Commission biologists who have relationships with landowners and knowledge of management issues there. Eighty male and female pronghorn have been captured and processed at the capture location to minimize handling time and animal stress. Researchers collected data on pronghorn age and genetics.
Then, the researchers attached ear tags to GPS radio collars, placed them on the pronghorn and released them. Katie Piecora, a graduate student in the School of Natural Resources, will analyze information transmitted by the collars from a Lincoln-based lab. The fine-scale data means there will not be many trips to the field required, Little said. If a collar goes motionless over several hours, the researchers will receive texts informing them of its location and a member of the project team can find out what happened to that pronghorn. Little said such incidents will inform the survival portion of the project. And the research project, Meduna said, will lead to a better overall understanding of the species.
“We have responsibility to not only the pronghorn, but to all Nebraskans, to better understand and better manage our pronghorn,” Meduna said. “Understanding these movements will help us tell the story of our pronghorn and in turn help landowners understand the role that they play in the annual cycle. It’s my hope that a better understanding turns into a greater care for this unique species.”