Bighorn sheep are battling in North Dakota, rebounding from a crippling disease outbreak in the Badlands and thriving on the Fort Berthold Indian Reservation.
Bighorn sheep numbers in the state are approaching a benchmark that seemed unlikely just a few years ago, when the disease raised concerns about a potential long-term population decline.
There are nearly 450 bighorn sheep among populations managed by the North Dakota Game and Fish Department, National Park Service, and Three Affiliated Tribes Fish and Wildlife Division. The next target is 500 sheep, with an end goal of around 600, according to big game and fish biologist Brett Wiedmann.
“If at some point we hit 600, that would be maxed out,” he said. “Bighorns, if the abundance gets too high, then you really run the risk of disease.”
Eight years ago, an outbreak of deadly bacterial pneumonia hit the West Badlands sheep population, but bighorn sheep have since rebounded to record numbers for two consecutive years.
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The Game and Fish Department’s 2021 bighorn sheep survey, supplemented by the lamb recount this month, found 335 bighorn sheep in western North Dakota, up 4% from to the 2020 record of 322 and 15% above the five-year average.
Biologists counted 99 rams, 175 ewes and 61 lambs. Not included in the count are about 40 sheep in the North Unit of Theodore Roosevelt National Park and bighorn sheep introduced to the Fort Berthold Indian Reservation two years ago.
“We were encouraged to see the number of adult rams increasing to near record highs, and adult ewes were at record numbers,” Wiedmann said. “Most encouraging was a record number of lambs matching a record recruitment rate.”
Recruitment refers to the number of lambs that become a permanent part of the flock.
The Northern Badlands population increased 6% from 2020 and was the highest number on record. The herd south of Interstate 94 continues to struggle and is at its smallest size – 12 – since bighorn sheep were reintroduced there in 1966. That’s three fewer than last year.
The southern herd has been decimated by disease over the years, and Game and Fish hopes to eventually wipe it out and start over, transplanting sheep from the Rocky Boy Indian Reservation in Montana. Flocks of domestic sheep in southwestern North Dakota have hampered the plans because they can spread the pneumonia bacteria to wild sheep.
“Our fear is that the rams will end up wandering over to these domestic sheep and bringing back these deadly pathogens,” Wiedmann said. “Better to go into standby mode until conditions change in the future.”
The 30 bighorn sheep transferred in January 2020 from the Rocky Boy Reservation to the Fort Berthold Reservation have thrived, nearly doubling their population in just two years, to 58. State and tribal wildlife officials call this a “performance exceptional demographic”.
The outbreak of bacterial pneumonia in Badlands sheep in 2014 killed about three dozen animals that year and a handful the following year. Game and Fish canceled bighorn sheep hunting season in 2015 for the first time in more than three decades. The agency reinstated hunting the following year, but warned it can take up to 15 years for the disease to work its way out of a herd.
The sheep have rallied, however, and the survey has now seen increased numbers for four consecutive years.
Officials found a low prevalence of the bacteria when monitoring sheep last winter, but biologists observed several bighorn sheep coughing during the 2021 survey, indicating the population has not completely eliminated the deadly pathogen, according to game and fish veterinarian Dr. Charlie Bahnson.
A bighorn sheep hunting season is tentatively scheduled for this fall. Season status will be determined on September 1, following a summer population survey.
Game and Fish typically awards fewer than 10 unique licenses per year. Five licenses were awarded last year, including one that is traditionally auctioned by the Midwest Chapter of the Wild Sheep Foundation to raise funds for sheep management. Four hunters managed to harvest a ram.
Bighorn hunting is hugely popular in North Dakota, and the permit lottery has set application records for four straight years, according to Wiedmann.
There were 19,127 applicants last year, according to Randy Meissner, hunting and fishing licensing manager, meaning nearly 4,800 hunters were vying for each available license handed out by the department. This year, 19,426 hunters applied, even though there is no guaranteed season.
Contact editor Blake Nicholson at 701-250-8266 or email@example.com.