JACKSON, Wyo. — This winter, the National Elk Refuge (NER) has had less elk visitation to date compared to last year at this time, but the herds have access to available forage and space to spread out, which keeps populations healthier.
According to NER, elk numbers have ranged from 5,300 to 6,000 elk on the southern half of the Refuge for the past two weeks. These estimates do not include the northern half of the Refuge, where terrain and forest cover make animals more difficult to count. There were 7,700 elk on the NER in late February, 2023.
The NER Senior Wildlife Biologist Eric Cole told Buckrail that since elk have space and are moving across the Refuge, it limits the spread of disease.
“Elk collar data suggest that there has been considerable back and forth elk movement between the northern and southern areas of the Refuge, which explains the recent variation in the number of elk counted in the southern survey area,” Cole said. “From the Refuge’s perspective, elk use of the north end of the Refuge is desirable because animals are spread out and less susceptible to disease.”
According to Cole, winter elk mortality has been below average to date, which is expected during in a relatively mild winter. There have been 47 elk mortalities documented so far during the 2023/2024 winter period, the majority of which have been older mature cows. Only 11% of elk winter mortalities have been elk calves. In severe winters, elk calf mortality is typically much higher because this segment of the population is more sensitive to limited forage and cold temperatures.
Cole explained to Buckrail that elk herds have not required supplemental feeding this winter due to a late arrival of snow, and sufficient forage growth this past spring.
As of Friday, Feb. 23, average available forage at NER monitoring sites was 510 pounds per acre. Historically, the Refuge has not initiated supplemental feeding until forage declines to 300 pounds per acre at these sites. The NER will continue to monitor conditions weekly to determine if feeding is necessary.
“For perspective, the latest date the Refuge has ever initiated feeding has been February 28,” Cole shared. “There have also been 10 winters that the Refuge has not fed at all, with the most recent non-feeding winter in 2018.”
Currently, the snow pack depth at the NER headquarters monitoring site is 18 inches. The long-term average snow pack depth on the Refuge in February is 13 inches, but since most of the snow accumulated since February 5, snow conditions have not significantly affected elk access to forage. At this time last year, the snow pack depth was 25 inches at the NER Headquarters monitoring site, and peak snow pack depth during the severe 2023 winter was 32 inches, according to the NER.
“Snow pack depth is currently above average for late February on the Refuge,” Cole said. “However, this is somewhat misleading because most snow accumulation in 2024 came late (February), and as a result the density of the snow pack has been relatively low. Elk have had little trouble accessing forage on the Refuge, and that is one of the main reasons why feeding has not been necessary so far in 2024. Other reasons for the delay in feeding are above average forage production during the previous growing season, a late elk migration to the Refuge and no bison using the Refuge during the 2023-2024 season.”
