Tales from the Tundra May 2025
Photo by Heidi Hatcher, ADF&G
June 12, 2025
Jack Cornish — ADF&G
As spring returns to the Copper Basin, some of its resident wildlife start to change their behaviors and begin migrating toward where they will have their young and spend the summer. Nelchina caribou are a clear example of this migratory behavior as they leave wintering areas across the basin to converge on their calving grounds in the Western Talkeetna mountains.
Calving is an important part of the herd’s yearly routine and has significant implications for herd recovery following the recent population decline. The Alaska Department of Fish and Game tracks productivity of the herd each spring and assesses the ratio of calves-to-cows in summer to evaluate the success of calving.
During these checks in 2022 and 2023, observed ratios of calves-to-cows were some of the lowest on record, leading Glennallen ADF&G to more intensively monitor Nelchina calf production and survival in May of 2024. This effort included more frequent checks of radiocollared cows to assess reproductive status throughout the calving period and collaring 32 newborn calves to better understand calf survival and sources of mortality. Calf radio collars were monitored daily, and mortality events were investigated as soon as possible to determine cause of death.
Preliminary findings suggest that eagles are a more significant predator than expected, accounting for half of predation based on available evidence. Additionally, certain factors appeared to predispose calves to mortality; male calves were more likely to die than females and larger calves had a greater chance of survival than smaller ones.
To further explore these dynamics and their potential impacts on the recovery and management of the Nelchina herd, ADF&G will expand this effort in 2025 by deploying 60 collars on calves throughout the calving period for monitoring. For further information on this work or for any other questions related to wildlife in this area, please reach out to Glennallen ADF&G at 822-3461 or Glennallen, ADFG@alaska.gov.
