Bighorns in western North Dakota have rebounded from an outbreak of disease seven years ago to reach record numbers, and the total wild sheep population in the state likely is at a historic level.
However, the herd south of Interstate 94 continues to struggle and is at its smallest size in about two decades.
The state Game and Fish Department’s 2020 sheep survey, completed with a recount of lambs this past March, showed 322 bighorns, up 11% from 2019 and 13% above the five-year average. The total surpassed the previous record of 313 bighorns in 2008.
About 40 bighorns in the North Unit of Theodore Roosevelt National Park and sheep recently introduced to the Fort Berthold Indian Reservation aren't included in the count.
Biologists counted 97 rams, 170 ewes and 55 lambs.
“We were encouraged to see the count of adult rams increase after declining the last four years, and adult ewes were at record numbers,” Big Game Biologist Brett Wiedmann said. “Most encouraging was a record lamb count corresponding with a record recruitment rate.”
Recruitment refers to how many lambs become a permanent part of the herd.
The good numbers reflect lessening effects of bacterial pneumonia detected in 2014, according to Wiedmann. It killed about three dozen sheep and prompted Game and Fish to cancel the bighorn hunting season in 2015 for the first time in more than three decades. The agency reinstated hunting the following year, but it can take up to 15 years for bacterial pneumonia to work its way out of a herd, according to state Wildlife Chief Jeb Williams.
Game and Fish typically allocates fewer than 10 licenses per year. Six were given out last year; a record 16,935 hunters applied. This year's license amount will be decided Sept. 1, after the summer population survey is completed.
The northern Badlands population is the highest count on record, but the southern Badlands herd declined to its lowest level since 1999 -- just 15 sheep. Game and Fish hopes to eventually eliminate the herd south of I-94 and start over, transplanting bighorns from the Rocky Boy’s Indian Reservation in Montana. Flocks of domestic sheep in the area have hampered the plans, as they can spread the pneumonia bacteria to wild sheep.
"We are not moving ahead at this time with transplanting bighorn sheep to the south," Williams said. "We are continuing to evaluate but won’t be any time soon."
Bighorn sheep were translocated in January 2020 from the Rocky Boy’s Reservation to the Fort Berthold Reservation. During the first year, only one adult ewe died and 19 lambs were recruited, increasing the population from 30 to 48.
There are more than 400 bighorns in North Dakota among populations managed by Game and Fish, the National Park Service and the Three Affiliated Tribes. Wiedmann said the last confirmed native bighorn sheep in the state was killed in 1905, and Theodore Roosevelt reported that bighorns were scarce by the time he hunted them during the 1880s.
“So, it’s likely there are more bighorns today than before North Dakota’s statehood in 1889,” Wiedmann said. “It really illustrates the historical significance of this year’s count.”
Reach Blake Nicholson at 701-250-8266 or email@example.com.