White-tailed ptarmigan The species name "leucura" was for a long time misspelt "leucurus", in the erroneous belief that the ending of "Lagopus" denotes masculine gender. However, as the Ancient Greek term "λαγωπους" is of feminine gender, and the species name has to agree with that, the feminine "leucura" is correct. The species name "leucura" is derived from the Latinized version of the Greek "leukos", meaning "white" and "oura", meaning "tail", in reference to the bird's permanently white tail. The white-tailed ptarmigan is the smallest of the ptarmigans and the smallest bird in the grouse family. It is a stocky bird with rounded
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