By Dr. Robert Seabloom

Seabloom’s book Mammals of North Dakota is available for purchase at NDSU Press.

In 2021, I wrote a bit about one of the Badlands’ smaller charismatic denizens, the Ord’s Kangaroo Rat. This time it’s a much larger one, our Bighorn Sheep, its near extinction and recovery. The bighorn had its origin in the Old World during the last ice age. It is in the cattle family, the Bovidae, along with bison, mountain goats and a plethora of other Old World and domesticated species. They crossed to North America via the Bering Straits Land Bridge at the end of the Pleistocene, the oldest North American fossils having been dated at around 110,000 years. We don’t know how long bighorns have existed in North Dakota but most fossil remains from Natural Trap Cave in northern Wyoming have been aged at 12,000 – 21,000 years before present. Erosional processes along the Little Missouri and Missouri Rivers in North Dakota would have been going on long enough to create the rugged habitat favored by the sheep. So, we could conclude that they were well-established and living along side of early Native American tribes as well, at least until the advent of white exploration and settlement in the early 19th century.

Discovery and Near Extinction

On May 25, 1805, the Lewis and Clark party was working up the Missouri River after spending the preceding winter with the Mandans. Clark’s journal entry for that day included, “I walked on shore and killed a female Ibi or big horn animal in my absence Drewyer & Bratten killed two others, this animal is a species peculiar to this upper part of the Missouri, the head and horns of the male which Drewer killed to day weighed 27 lbs. ----”. This event occurred in the Badlands bluffs of the Missouri between the mouths of the Little Knife and White Earth Rivers just northwest of the present New Town. So, began the 100-year slide of this fascinating charismatic species to extirpation from North Dakota.

Teddy Roosevelt hunted bighorns in the Little Missouri Badlands in the 1880’s, but by that time the population had been so reduced by earlier adventurers he found them difficult to hunt. The last of the original bighorn population was killed along Magpie Creek west of the Killdeer Mountains in 1905.

Vernon Bailey, former chief biologist of the old Bureau of Biological Survey and author of his (1926) “A Biological Survey of North Dakota I. Physiography and Life Zones II. The Mammals,” wrote in his bighorn account, “In the destructive and constructive periods of the West, as it passed from savage to civilized life, the bighorn of this open and accessible area contributed its all. Besides its most savory of wild meats, its magnificent head and horns offered a highly prized trophy not often obtained in the low country or where hunting on horseback was possible. Whether for sport or profit there was always a high price on the head of the bighorn, and this spells the doom of any species.” Similar events took place throughout the deserts, rough arid grasslands, and high country of the west, bringing about the near extinction of the species.

Habitat, Habitat, Habitat!

1895: A couple of contributors to the demise of bighorns in North Dakota, courtesy North Dakota Historical Society

“Habitat, Habitat, Habitat!” This was the response a few years ago when a few of us were asked what the three main factors are affecting North Dakota wildlife. And that certainly applies to bighorns. Bighorn researchers have denoted two principal components of bighorn habitat, foraging areas and escape terrain. Once, one of my students and I wanted to get a better look at a group of ewes foraging in the distance. So, we “bellied” closer, carefully keeping heads down and using tall grasses and shrubs as cover. When we were about 200 yards from the sheep, we decided to take a look, very carefully moving the cover aside. There they were, looking straight at us – they had known all the time! When real danger (like coyotes) threatens, the bighorns will take off from foraging to the nearest escape terrain, steep rugged terrain with at least an 80% slope and 10 meters vertical rise. A problem for much of North Dakota’s bighorn habitat is the distance of escape terrain from many foraging areas. So, while adults escape, many (up to 90%) of young lambs do not, providing tasty meals for local coyotes.

Once the sheep reach escape terrain there is usually little a potential predator can do about it. Bighorns are remarkably well adapted to utilization of their escape terrain. Their sharpedged hooves with concave bottoms enable them to dig into steep slopes with tiny ledges unavailable to other animals. They are excellent jumpers, giving them the ability to achieve safety on the slopes before the predators arrive. So, while the adults may have a good chance for longevity, the picture for lambs is another story.

Recruitment

Lamb survival is contingent on two major hurdles, predation (primarily coyotes) and disease. As mentioned above, proximity to escape terrain is essential and most foraging occurs within 300 meters of it. If foraging is too far out, the ewe might escape an attack, but the lamb is lunch. The second is if the lamb survives the summer, in the fall it is likely to contract lungworm-related pneumonia which has ravaged bighorn populations throughout the west. It is carried by domestic sheep and goats, which are able to survive infection with little harm. I was told that some years ago goats were brought into the southern Badlands as an experiment to control leafy spurge. Within a year the southern Badlands bighorn population was essentially gone.

Introductions

Obviously, this is what got the process started in our state but consider all of the negotiations among the interested/affected regulatory entities. And then begins the complex planning process leading to capture, transport and release.

Unless handled very carefully, captured sheep get readily stressed, go into shock, and die (Capture Myopathy). Veterinary assistance is required.

High Expense – Helicopters, specialized personnel, telemetry, etc. don’t come cheap!

In 1956, North Dakota was one of the first states to attempt reestablishing bighorns within its boundary. After much negotiation sheep were captured and brought in from arid regions of British Columbia and in subsequent years from other western U.S. states as well. The population grew slowly or remained stable at about 320 animals. However, because of favorable reproduction and survival in recent years the state population may now be as high as 500 animals, according to ND Game and Fish Biologist Brett Wiedmann, who attributes the gain to recent reintroductions from habitats in Montana similar to North Dakota’s northern Badlands.

Once bighorns are released in favorable habitat they develop a high home range affinity and do not readily disperse. If some are to be used to “seed” new sites, they must be physically moved.

Interactions with Humans

In the wild, bighorns are very shy and wary of any sort of human activity. Our studies in the Badlands indicated negative responses to oil development activity, including vehicles, low flying aircraft, drilling, etc. and resulting in denial of foraging habitat and lambing grounds. Routine activity by ranchers did not seem to affect their behavior.

Prolonged exposure to human activity, especially in park-like situations, can result in habituation, not good for sheep or people (although tourists love it), and leading to accidents, disease transmission, injuries, and a degraded wilderness experience. I’ve seen habituated sheep in South Dakota (Badlands National Park), Colorado (Front Range) and New Mexico (Pecos Wilderness). In the Pecos, full-curl rams would crowd around us, wanting to lick the salty sweat off our arms!

Harvest

In North Dakota, about 5 rams are harvested annually, via lottery or auction. Recently there were 19,000+ applicants for a once in a lifetime license. Maintaining a bighorn population based on license sales alone and some federal aid money certainly doesn’t come close to covering the management requirements of the species. However, one license is set aside annually for auction by the Midwest Chapter of the Wild Sheep Foundation which provides funding for bighorn management in North Dakota. This year’s auction tag raised $135,000 and will go a long way in restoration of a once extirpated species to North Dakota.

Public Information and Acceptance

A frequent failing in the wildlife field has been in convincing the general public of the soundness of its conservation programs. Historically, wildlifers would much rather be out in the woods or prairies than making speeches in town halls. And that certainly applies to bighorn sheep as well as ducks or mulies. Why should a wealthy few be privileged to buy a tag when thousands of average folks have to take their chances on being drawn on the few remaining? Well, the answer, I think, was covered above. Furthermore, many fail to recall that in the late 19th century it was wealthy sportsmen who had the foresight to realize the imminent loss of the quarry they loved to hunt and had the means to do something about it. It was hunters like Teddy Roosevelt and George Bird Grinnell who founded the Audubon Society, Boone and Crocket Club, National Parks Conservation Association and others. They fought to prevent the extinction of the bison, obtained protection for Yellowstone National Park, helped found Glacier National Park, and the list goes on. Today many of the same organizations are still active, and newer ones are carrying on, including the Wild Sheep Foundation. Its quite a legacy, for which all of us who love wildlife and wild places should be grateful.

Dr. Bob Seabloom is one of the authors of Mammals of North Dakota (NDSU Press). Seabloom’s book Mammals of North Dakota is available for purchase at NDSU Press.

PDF: Wild Badlands #50 Spring 2023

Badlands Mammals II: North Dakota Bighorns