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Researchers Investigating Stagnant Pronghorn Population in Western Colorado
by OUTDOOR HUB REPORTERS on MARCH 7, 2012

While research begins into the reason for why the population of pronghorn is stagnant in the southwest corner of the Grand Mesa in Colorado, hunting of the animal in that area is suspended. According to Joe Lewandowski, spokesperson for the Colorado Parks and Wildlife Division, permits to hunt pronghorn in that area have not been issued for the past five years.

�The population couldn�t sustain hunting,� Lewandowski said. �What we�re hoping is that if we can figure out what�s going on with this animal� that eventually we might be hunting [pronghorn] again.� But Lewandowski warns that this is a long-term project and permits may not be issued for at least another five years.

Lewandowski speculates that habitat loss could be a reason why the population is declining in Mesa and Delta counties. �There�s been a lot of development in that area. It might be tough for them to make a living.� The study just began earlier this year in mid-February. Catch the full press release on the study below.

Original press release issued by Colorado Parks and Wildlife on March 7th, 2012
Colorado Parks and Wildlife biologists and managers have started a study in western Colorado to try to determine why the population of a small herd of pronghorns is not growing.

In an area of Delta and Mesa counties, just southwest of the Grand Mesa, is a herd of about 100 pronghorns descended from animals transplanted to the area in the 1970s. During the last 10 years, agency biologists and managers have noticed that groups of the animals are getting smaller and the overall size of the herd is declining.

�Very few fawns are surviving and we don�t know why,� said Brad Banulis, terrestrial biologist for the Montrose area. �We hope that this study will help us figure out what�s going on in this herd.�

Two operations kicked off the research.

On Feb. 19, the agency captured 19 pronghorns from the herd. Radio collars and ear tags were placed on 10 of them, and neck bands and ear tags were placed on the other nine. The collars and bands will allow biologists and managers to track the animals� movements and to spot them from a distance.

On March 1, 24 pronghorns were captured south of Limon in eastern Colorado and taken to a site near the Delta-Mesa County line where they were released. Nine of the animals were fitted with radio collars and the others received ear tags and neck bands.

All the animals captured also received a vaccine that fends off viruses that cause hemorrhagic diseases in ungulates. The diseases can be fatal to deer and pronghorns.

The transplanted animals will join up with the existing herd, Banulis explained. Their movements will be tracked and Parks and Wildlife employees will be able to determine what habitat they are utilizing, if they are having young and if fawns are surviving.

�This is the first time we�ve done any research on this herd,� Banulis said. �The ability to track these animals will provide us with a lot of valuable information.�

No pronghorn hunting in this herd�s area is allowed currently.

�The trap and release operation went very well,� said Frank McGee, a district wildlife manager in Grand Junction. �The field staff has been working for several years to identify ways to improve this population. Now we have a method that will allow us to figure out what�s going on with these animals.�

Also on March 1, 74 pronghorns were released in the Gunnison Basin to supplement that population.

To learn more about pronghorns in Colorado, see: http://wildlife.state.co.us/WildlifeSpecies/Profiles/Mammals/Pages/Pronghorn.aspx.

I don't buy the loss of habitat.I live NE of Colorado Springs.Once I was 25 miles from town.Now I have 3 Walmarts within 12 miles of me,many more homes and businesses.There is a herd of goats dwown the road and they are not hunted. Every year it gets bigger and bigger.
My expeience has shown that the goats adapt to human encroachment just like whitetails.

I'd be looking at poaching and coyotes.

I remember the post a couple of weeks ago showing the pronghorns bedded on the lawn of the Wyoming Game and Fish headquarters in Cheyenne--not exactly the outback.

Coyotes love to snack on fawns. Guessing that might be an issue.

Ya I got the email today about this

Lewandowski speculates that habitat loss could be a reason why the population is declining in Mesa and Delta counties. �There�s been a lot of development in that area.

Best pronghorn bucks in Western CO are probably in downtown Craig.

Drive through Cheyenne and you'll see tons of goats all around town, especially at the air force base. They don't care. My guess is poachers and coyotes.

The goats on F.E. Warren will make your jaw drop!

F. E. Warren has lots of good, open grasslands and fawning habitat. That's probably what is being taken by development in SW Colorado. When does are squeezed into small remnants of fawning habitat, the density of fawns on the ground makes it energetically efficient for coyotes to hunt them. Under those circumstances, they get a way higher proportion of the fawns that are dropped and recruitment suffers. When does are scattered about in expansive habitat, coyotes opportunistically take some, but nothing like they get in the situation described above.

Western Slope has expansive habitat. It looks like southern Wyoming. It's just not that much more developed than anywhere else. There are tons of goats out on the Eastern plains of Colorado Springs and there's REAL development out there. And plenty of coyotes.

Hopefully they will figure it out. It could be fences blocking migration routes, causing a bigger winter kill. It happened north of Rawlins, Wyoming back in the late 1980s...

Have you driven around out there lately?

I lived in Prescott, AZ ... 'Lope love the city. If I had the biggest buck in Prescott Valley, AZ on my wall I would be happy to quit antelope hunting ...

That was my first thought, too. A few years back I read where NM or AZ (forget which) did a study and killed some yotes and the fawn survival rate went off the charts.

Yep -- I work all over the state. I grew up with goats. When the weather gets tough in the winter, they'll push into town for forage. They aren't bothered by development. However, they are bothered by fencelines, harsh winters and coyotes. The biologists will figure it out, but it's unfortunate the area is getting shut down...

I have some friends out in Eastern CO.The goat herd was going down and the DOW came up with a whole bunch of ideas. Then the guys got serious when the coyotes started to run out of goats and started to pick on calves.One weekend they killed 35 coyotes and keep after them constantly.Goats are again plentiful and DOW still hasn't a clue.

Twenty years ago, the biggest pronghorn buck I've ever seen was in that herd--I even tried to draw it, but it has always taken a lot of PP's.

Most of the local biologists are thinking coyotes--but nobody can say why coyotes didn't have this effect for the previous 20 years. On the other hand, maybe coyotes is what kept the herd from growing.

I've always thought they started out with too small of a transplant to overcome normal mortality like predation. A larger intial transplant has a better chance.

This herd has always been an afterthought for the CDOW anyway.


Casey

Arizona has a casebook study. In the 70's they restored pronghorns to a historical pronghorn range where livestock grazing in the early 1900's had practically destroyed the habitat. Reduced grazing had restored the habitat and the forage was considered excellent.

Initially, the fawn survival rate was very high, then it dropped to almost nothing. Telemetry on the fawns showed high coyote predation.

For the next 4-5 years Arizona started shotgunning coyotes from a helo just prior to does giving birth. Fawn survival rate went way up. The herd grew to a point the biologists felt the herd could prosper with normal coyote predation, so they stopped shooting coyotes. Last I knew the herd has continued to prosper and they've been hunting them for decades now.

It is a classic example of a predator pit.

Casey