News: Wyoming Study Shows How Growing Wild Horse Populations Impact Sage Grouse Survival
A University of Wyoming study spanning nearly 15 years indicates that overpopulated wild horses are having a significant, negative impact on sage grouse survival rates in Wyoming. The research, recently published in The Journal of Wildlife Management, suggests that high densities of free-roaming horses correlate with reduced sage grouse nest success and lower survival rates of chicks and juveniles, threatening the imperilled bird species that depends on sagebrush habitats.
Ecologist Jeff Beck led the study, which monitored almost 1,000 GPS-tracked sage grouse across different horse density regions, stretching from Adobe Town in the Red Desert to Conant Creek in central Wyoming. The findings indicate that when wild horse populations exceeded the Bureau of Land Management’s (BLM) “appropriate management level,” sage grouse nesting and chick survival dropped markedly. In areas where horse numbers were triple BLM’s target, nest survival fell by 8%, and chick survival declined by 18% in early stages of life. Juvenile sage grouse older than 35 days saw survival rates plummet by 18% under similarly high horse densities.
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Interestingly, adult sage grouse did not experience the same impacts. However, the study provides insights into why younger birds are at risk. This aligns with prior research from Nevada, which showed that each 50% increase in wild horse populations correlated with a 2.6% annual decline in sage grouse numbers.
The Wyoming study explores underlying mechanisms behind this trend. Biologist Megan Milligan, a U.S. Geological Survey partner on the research, explains that habitat degradation by horses appears to be the primary issue. While horse trampling could occasionally affect nests, the main impact likely stems from habitat alteration. Horses can disrupt sagebrush, leave bare ground, and heavily impact riparian zones—key areas for food and shelter. This habitat damage makes young sage grouse more vulnerable to predators and restricts access to critical resources, particularly in the dry summer months when horses and sage grouse both concentrate around water sources.
Questions about other grazing animals, like cattle, also come up. But Beck suggests that cattle and sheep grazing don’t impact sage grouse habitat to the same extent, since livestock can be moved seasonally or removed if they cause habitat issues. Wild horses, however, remain in the habitat year-round and often exceed federal population goals, despite periodic roundups.
Managing wild horse populations is a contentious issue, as roundups are often met with resistance from advocates and sometimes delayed by legal challenges. But Beck emphasizes that strategic horse management—keeping populations below maximum levels—is critical to protecting sage grouse habitat and enhancing the species’ chances of survival.
“We’re not advocating to remove all wild horses,” Beck explains. “But effective management to keep horse numbers in balance is essential if we want sage grouse to thrive.”
This research is part of an ongoing collaboration between the University of Wyoming and the U.S. Geological Survey to understand how wild horse density affects sage grouse and their habitat. Future studies aim to expand beyond Wyoming to explore whether these relationships hold across the sage grouse’s broader range. This work will help wildlife managers make informed decisions about conserving sagebrush ecosystems and balancing management priorities in these complex, shared landscapes.
Really ? I can’t imagine that all the cattle that are grazing on those lands has anything to do with the grouse population. As usual, people always blame something else when in fact they are the problem.
It’s not surprising that these lies are being spewed about the wild horses, especially considering the Governor of Wyoming, Mark Gordon, is a cattle rancher.
The last I heard it is sheep that graze The Roots of grass to the ground level. And, ultimately, it is man who destroys what was there before he came. Having lived in ranch country many years, if it weren’t for the greed of a few people there would be enough for all. It is the misuse of –including land ,that destroys ultimately what could have been.
Got that right. Nothings said about cattle doing the same thing.
Got that right. Nothings said about cattle doing the same thing. Leave those poor animals alone. Enough is enough!.
I can say with as a retired Blamer who worked to help get implemented the sage gross restoration plan that when sage grouse habitat and brooding grounds where damaged enough that the populations dropped in that area, we were told that even if cattle were the actual cause of the decline due to cheat grass and cattle use we were to find another cause. Ranchers doing the same thing over and over for generations has destroy the sage brush habitat but ranchers don’t have to take responsibility. Mostly it’s we’ve been doing it this way for years why should we change.
I feel exactly like Suzanne blame the wild horses for the problem but not the rich cattleman’s cattle. OH NO.
I agree even if livestock are moved seasonally to other spots does not mean they are not effecting the sage grouse habitat. Because cows pretty much mow and trample all the vegetation , whereas wild horses create paths through their environment that they follow and don’t just trample everything down 🧐 and also reseed the environment with their manure. Cows do not at all . 🤨
STOP SPEEADING LIES. WYOMING IS FILLED WITH CATTLE RANCHERS. EVEN THE GOVERNOR OF WYOMING IS A CATTLE RANCHER. BAN ANIMAL AGRICULTURE.
Has there been a study to show the effect sheep & cows have on the range?
Wyoming the cows and sheep are pretty thick
In your parts
Remove them and watch Wyoming flourish
How many cattle and sheep are on our public land?
This article is BLM putting out more lies about wild horses
These studies fall right into the BLM and cattleman’s false narratives. They ignore the real science so that they can continue to remove the wild horses from the range that was given to them by the free roaming wild horse and burro act of 1971. Governor Gordon hire some real scientists to do these tests.
More LIES about wild horses There is no justification to have 150 horses on 50000 acres yet allow 10000 cattle there. Horses are beneficial; they attract wildlife, trim vegetation not up root it thus naturally reseeding with native vegetation . This prevents wildfires. Cattle&sheep destroy the landscape,kill the vegetation& leave the land barren. The drugs given to cattle/sheep are passed onto the land and toxify it . This article is fake,it conveniently favors ranchers who are destroying our land for free.
I agree with many of the comments. The study is flawed as it doesn’t consider the effects of cattle and sheep grazing on these public lands. I am sure their numbers are much higher than the number or wild horses. I am so tired of our tax dollars supporting an agency that is actually a pawn of corporate ranchers.
This article is totally biased. Cattle and sheep permitted to graze on public lands owned by welfare ranchers outnumber wild horses by the thousands/millions. The BLMs data depicts livestock causing degradation on our public lands. This article is nothing more than biased information blaming wild horses when welfare ranchers livestock are the culprits. Humans responsible for this article must have ties to the RSGA, are married, engaged, dating or in some kind if relationship with welfare ranchers. Lies! Corruption!
Jeff Beck is always blaming the wild horses. Yes, numbers need to be safely monitored. All this does is inspire the BLM to roundup more wild horses and keep them in holding. That is if the horse survives the roundup and doesn’t fall out the back of the trailer as recently happened, or break their neck, or get kicked in the face by a wrangler with spurs when the mare collapsed from exhaustion. Quit blaming the horses.
What is so special about the Sage grouse anyway?🤔
There is no such thing as a “wild horse” anywhere in the Americas. They are FERAL horses, calling them wild confuses the issue. If your house cat runs away we won’t call it a “wildcat.”
These invasive animals need to be removed, entirely. Bovines, on the other hand, are native to our lands. Saving the feral horses is like saying “Save the Asian Carp.” Fact, keep your pet horse in the stable.
Cattle and sheep are the invasive species- both evolving/domesticated in the Middle East. Any scientist will acknowledge that horses evolved in North America and spread to the rest of the world via the Bering Sea Land Bridge. In fact, new evidence from northern N. America is showing that horses were here 5,000 years LATER than the old thinking that they died out 10,000 years ago!!! Then they were re-introduced by the Spanish in the 1500’s. Horses have EVERY right to be here!!