Series: Dall Sheep in Alaska's National Parks

Media Included

  1. Climate Change and Dall Sheep - Learn more about Dall sheep and climate hange. *** Note: This video contains no sound.

How might climate change impact the world's northernmost wild sheep population?

ewe and lamb on a rocky outcropping

NPS Photo / Kent Miller

Dall sheep are considered an indicator species by the National Park Service, which means they are a species with a limited range and specialized habitat and sensitive to local environmental change.

Changes in Dall sheep abundance, distribution, composition and health may indicate changes happening with other species and ecosystem processes. Dall sheep live in alpine, or high mountain, areas. These areas are expected to experience significant changes associated with climate change.

Changes may include shifts in locations of plant communities (e.g., an increase in shrubs in alpine areas), diversity of plant species (e.g., loss of important forage species for sheep), and local weather patterns (such as increased incidence of high winter snowfall and icing events), which may affect sheep distribution and abundance.

In Depth

scientists on a mountainside
Scientists monitor the sensitive alpine plants that make up the main food for Dall sheep

NPS Photo

Alpine Plant Communities

Some species are expected to benefit from climate change while others will not. Shrubs and woody plants typically dominate plant communities at lower elevations. As elevation increases, the dominant plant community transitions to one dominated by low-growing grasses, flowers, and lichens. Warming climate trends, longer growing seasons, and changes in precipitation have the potential to allow woody plant species to find suitable habitat at higher elevations.

As a result, low-growing alpine species may be out-competed or shaded by the encroaching woody plants. Because of this vulnerability, alpine plant communities are monitored by NPS to track species abundance and diversity. Changes in the seasonal availability and diversity of alpine plants may affect Dall sheep populations by altering sheep diets and consequently where they can live in mountain parks, as well as ewe pregnancy rates and lamb growth and survival.

Learn more about the Arctic Network’s vegetation monitoring program