FWP studying Madison pronghorns
Seasonal ranges, movement corridors are the focus
ENNIS – During January, Montana Fish Wildlife and Parks (FWP) personnel conducted a new pronghorn antelope study in the Madison River valley.
According to Bozeman-area FWP Region 3 Wildlife Biologist Julie Cunningham, FWP completed a pronghorn capture program in the Madison Valley, where they successfully captured and collared 40 female pronghorns; 22 east of the Madison River, and 18 west of the river.
The locations of the captures ranged from McAllister, south to Wall Creek.
So why was FWP basically lassoing some of the 2,500 pronghorns from helicopters?
“The purpose of this study will be to learn about the seasonal ranges and movement corridors between them for Madison Valley pronghorns,” Cunningham said. “For years, we have observed that approximately half of the pronghorn that are winter residents of the Madison Valley leave during the summer time. We have observed pronghorn in unusual summer ranges, including the Hebgen Basin and at high elevation along the Gravelly Range Road. We have seen a possible staging area near the Highway 287-87 junction, and believe some may migrate into Idaho in the Henry’s Lake area, or even the Centennial Valley.”
“We are interested in learning about partitioning of animals across the winter ranges to more effectively manage the population and its important habitats,” she continued. “Learning about seasonal ranges and migratory routes can help us work with other agencies, conservation groups, and private landowners to help keep these routes protected into the future.”
FWP believes that about half the Madison valley pronghorn herd is migratory in a given year, but little is known about these migrations.
“I will also be curious to see if there is any herd structure from north to south or east to west in the valley,” Cunningham said. “The Madison Valley hosts up to 2,500 pronghorn in winter, a large population. This is really special for southwest Montana. These pronghorn live in an inter-mountain valley.”
This study has been of local interest and discussed for years, Cunningham said.
What sparked it finally happening was how FWP got funding through a U.S. Department of the Interior Secretarial Order to identify and conserve large ungulate migration corridors and winter ranges.
FWP is collaborating with federal and non-profit partners as well as local landowners in the community to do this study, she noted.
During winter, pronghorn – primarly grazes of forbs and grasses during spring, summer and early autumn – focus more on cactus and sage as their primary food sources.
Seasonal migration may play a role in why the Madison valley hosts so many pronghorns.
“Ungulate migrations are often influenced by snow and vegetation,” Cunningham said. “This study will help us learn more about this.”
“In elk,” she continued, “we talk about the ‘green wave’ – grass greens up at low elevation first, but as low-elevation grasses dry out, they (elk) move uphill where the snow is melting off and that grass is greening up.”
“Pronghorn are not usually elevational migrants. They may, however, use migration facultatively to adapt to year-to-year changes in vegetation availability.”
“I like to remind people about what an interesting species pronghorn are,” Cunningham said. “They are not related to deer and elk as closely as many people think, nor are they true antelope, like one sees in Africa. Rather, they are the sole member of their family, Antilocapridae (deer and elk are Cervidae, true antelope are in the family Bovidae, and even bighorn sheep and mountain goats are in the Bovidae family).”
“So where did pronghorn come from? The amazing answer is they are ice-age survivors. Yes, this species roamed the plains with sabre-toothed tigers, American cheetahs, and woolly mammoths. This is a relict species, an ancient species. That’s why they have such unique horns. Their horns are indeed made of keratin (like our hair) and they shed off every year. Some people think they are like antlers because they shed, but antlers are made from bone. Pronghorn have bony protuberances off their skulls, just like bighorn sheep, but bighorn sheep horns are made of a different type of keratin (like fingernails) and they never shed.”
“And what is their closest relative? Amazingly, it’s the giraffe!
“The Madison Valley is a special place for conservation,” Cunningham continued. “Landowners have generously allowed us to complete this study, to capture, and to follow these tagged animals.”
I’ve been asked over and over by landowners, local conservation groups, and even high school science students about how to make fences wildlife-friendly, where they should focus efforts, all to help pronghorn and other species move freely across the landscape.”
“As the Madison Valley continues to grow in population through subdivision and through recreational visitors on the highways, having good information about pronghorn movements will help us all to maintain these animals’ ability to have what they need on the landscape.”
During the fall, Cunningham said, up to 500 hunters come to the valley to hunt pronghorn.
“These sportsmen and women have on average 75 percent success rates,” she said, “with an average of three days of effort. This herd provides the ability for up to 500 license holders to hunt pronghorn locally – they don’t have to drive to eastern Montana.”
“FWP hopes to see pronghorn populations persist and hunting opportunities continue in perpetuity,” Cunningham said. “The herd seems to be doing well, and our goal is to keep it doing well.”
“There are occasional game damage complaints from pronghorn, areas of local abundance. FWP is curious to see if there is strong herd structure in the Madison Valley, whether the pronghorn on the east and west sides interchange and how much they do. If there is evidence of a herd structure, perhaps hunting regulations can be altered to help localize hunters on areas of abundance and game damage while keeping the herd as a whole healthy for future generations.”
“So many people deserve thanks for this project,” Cunningham said. “Quicksilver Aviation is an efficient and professional capture crew whose experience net-gunning wildlife brought fantastic results. Dean Waltee, the FWP Sheridan biologist, and FWP pilot Neil Cadwell piloted the spotter plane tirelessly, making note of every capture boundary and fenceline, how cattle and horses were behaving, and where the pronghorn were. Neil and Dean worked to make sure we captured only where we had permission and to make sure we did not disturb the livestock on the private lands.
“Our research division, particularly Kelly Proffitt and Jenny Jones, made this capture happen, doing all the organization, budgeting, collar preparation, and capture contracting.”
“Special thanks go to the landowners in the Madison Valley. We had 25 Madison landowners who gave us permission to do this capture on their lands. We could not have dreamed of getting this done without them. These landowners accepted the disturbance of the helicopter flying over their homes and ranches all day to enable us to learn about the pronghorn they live with.”