White-tailed ptarmigan and development of the chicks. This suggests that the hens' food calls assist in enhancing survival rates of juvenile ptarmigans. The young birds remain with their mother throughout the summer and autumn season. The white-tailed ptarmigan is well-camouflaged when on the ground. In his pioneering 1909 book on the subject, "Concealing-Coloration in the Animal Kingdom", the American artist Abbott Thayer wrote: The white-tailed ptarmigan has feathers located on its feet to serve as protection from the extreme cold often experienced in the alpine tundra environment. In addition, these birds have feathers around their nostrils to warm the air prior to
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.