Nelchina Caribou Herd Update

Heidi Hatcher, area biologist from the Department of Fish and Game’s Division of Wildlife Conservation, gave an update on the status of the Nelchina Caribou Herd on Friday, February 20 at the Wrangell-St. Elias National Park Visitor Center. In attendance were members of the public who came to hear Hatcher speak on the future of caribou hunting and wildlife conservation efforts in our area.

Due to a large population drop following two subsequent winters with severe snowfall, the size of the Nelchina herd dropped below 10,000 in 2023. Caribou hunting in the region has remained closed since then in hopes of giving the herd time to regain its ideal population of 35,000-40,000 caribou.

Every year, Hatcher and her team use many different metrics to estimate the size of the Nelchina herd. They conduct a spring parturition survey to estimate what proportion of adult cows are pregnant or have recently calved. In the summer, they compile population data using techniques including radio collaring, photography, and helicopter surveys to get a more thorough picture of the herd’s numbers.

The department’s goal is to maintain the herd at a managed population of around 35,000-40,000 caribou following the fall hunting season. It’s important to note that numbers alone aren’t the only metric used to determine how healthy the herd is, whether the hunt should be opened, or how long the hunting season should last. The department also looks at the ratios of bulls to cows and cows to calves, cow pregnancy rates, calf mortality, calf weight, and the overwinter survival rates of both collared calves and adults.

Hatcher stated that red flags about the Nelchina herd’s health were raised as early as 2019, when calf weights dropped and the number of females becoming pregnant decreased, both of which may be signs of nutritional limitations. 

The next two winters brought extreme snowfall, and around one-third of the adults in the Nelchina herd died in the 2020-21 season. (As a comparison, during a more typical year, Hatcher’s department sees 80-85% of the herd survive the winter.)

Even after these harsh winters, the Nelchina herd has continued to show disturbing signs of small calf size, decreased calf survival, later calving dates, and calves being born with gestational dysmaturity (showing signs of premature birth although carried through a full gestational period). Other calves are being born without antlers or their antlers are brittle and break off. The full reasons for these health indicators are unknown, but Hatcher suggested they may be at least in part linked to nutritional deficiencies experienced by their mothers.

Hatcher indicated the caribou hunt will remain closed into the 25-26 hunting season, but she hopes that the herd will have time to increase in health and numbers so that they can consider opening it back up in the fall of 2027.

Hatcher has worked as a wildlife biologist for the Division of Wildlife Conservation for the past ten years. Her lecture last month was part of the Science Lecture series hosted by WISE and sponsored by the Alyeska Pipeline Service Company. A herd update she gave in January with the same data sets and similar information is available on the Alaska Department of Fish and Game’s YouTube channel.