White-tailed ptarmigan cover. The white-tailed ptarmigan was introduced into the Sierra Nevada of California, Wallowa Mountains in Oregon, and Uinta Mountains of Utah in the 1970s. It may have been native here during the early Pleistocene but became locally extinct due to climate changes with greater snow-cover in spring impacting on its breeding season. Alternatively, it may have been unable to colonize the Sierra Nevada because of the barriers provided by the Columbia River and the Great Basin, and the low altitudes of the intervening South Cascades. This herbivorous bird's diet varies seasonally. Nitrogen-rich snow buttercup leaves are favored in the spring
Arctic Report Card video that summarizes the Report Card. In 2015, Arctic sea extent at the end of the winter was the lowest during the satellite record and the winter maximum occurred 15 days earlier than in the past. The sea ice minimum at the end of summer was the 4th lowest extent on record. These changes are having profound impacts in both the marine and terrestrial ecosystems and in sea surface temperatures. Arctic Report Card The National Oceanic and Atmospheric Administration's Arctic Report Card presents annually updated, peer-reviewed information on recent observations of environmental conditions in the Arctic relative to historical records.