By Katie Watt
The Rocky Mountain bighorn sheep herd in Radium, also known as the Radium-Stoddart population, has been on the decline since the early 2000s, but wildlife biologists say there’s nothing to be concerned about.
Since this herd of sheep frequently visit Kootenay National Park, Parks Canada works with B.C. Ministry of Forests, Lands, Natural Resource Operations and Rural Development (FLNROD) to document population numbers. To monitor the population, wildlife specialists complete ground counts throughout the year to estimate the population size of the herd. It is normal for wildlife populations, including bighorn sheep, to experience fluctuations over time, according to a ministry spokesperson. For the Radium-Stoddart herd, their numbers have been on the decline since the early 2000s.
The last counts, taken in 2017, estimated that there are currently 150 sheep in the Radium-Stoddart herd, which is around a 25% decrease from the numbers taken in the early 2000s count. Records dating back to the 1920s, however, indicate that the population has decreased to numbers lower than 150 in the past.
Various aspects have led to the deaths of these sheep. It is suspected that the main contributor, however, have been cougars. During winter of 2017-18, Parks Canada, in conjunction with B.C. Conservation officers, a local Compulsory Inspection contractor, and local volunteers, counted a total of 28 deceased bighorns; officials suspect that 21 of these deaths were attributed to cougars, five to vehicles, and two to trains. Potentially, the presence of a mother cougar and two cubs may have played a role in the higher number of conflicts this year.
“A cougar must feed on an average sized deer every 7-10 days, but with cubs that number goes down to every 3.1 days,” says Andrew Milne, local Conservation Officer. Some sheep were also killed within the town. When this happens, the carcass of the animal must be removed quickly as to reduce the amount of human-wildlife encounters, even if the carcass has not been fully eaten by the predator. This removal of an active meal can increase the amount of sheep kills.
While cougars are suspected to have played a large role in sheep kills this year, population can also be affected by illness, winter severity, or a lack or surplus of food.
While these numbers may seem surprising, there is little to be worried about, says a spokesperson from FLNROD.
“The current population size of the bighorn sheep herd in Radium Hot Springs is considered to be reasonably healthy and within long-term documented population numbers,” the spokesperson said. “If the population were to decline significantly and create concerns, Parks Canada will work with FLNROD to manage the herd as needed.”
Due to the high number of observed bighorn deaths in 2017, Parks Canada and FLNROD will be keeping a close watch on sheep numbers this winter.