Rock ptarmigan been allowed again since 2005, but is restricted to selected days, which are revised yearly and all trade of rock ptarmigan is illegal. In Thomas Bewick's "A History of British Birds" (1797) the species is named as "White Grouse" with alternatives "White Game, or Ptarmigan". The birds feed, records Bewick, "on the wild productions of the hills, which sometimes give the flesh a bitter, but not unpalatable taste: it is dark coloured, and has somewhat the flavour of the hare." Rock ptarmigan The rock ptarmigan (') is a medium-sized gamebird in the grouse family. It is known simply as the
Arctic fox regulation. Also, the Arctic fox has a beneficial mechanism in their nose for evaporative cooling like dogs, which keeps the brain cool during the summer and exercise. The thermal conductivity of Arctic fox fur in the summer and winter is the same; however, the thermal conductance of the Arctic fox in the winter is lower than the summer since fur thickness increases by 140%. In the summer, the thermal conductance of the Arctic foxes body is 114% higher than the winter, but their body core temperature is constant year-round. One way that Arctic foxes regulate their body temperature is by