BIOL 1902 Lecture Notes - Lecture 7: Freezing Rain, Glycerol, Countercurrent Exchange
9 Sep 2017
School
Department
Course
Professor
Document Summary
Snowshoe hares gain 27% in coat"s insulation value by being white. More north or south an animal is, the more likely it is pale. Allen"s rule: in northern regions, animal extremities tend to be smaller. Bergmann"s rule: the farther north you go, animals have a more rotund shape, low sa to v ratio. Arctic fox has long tale which is strange. Tale is relatively small but has lots of fur to maintain heat. Sleeps with tale in front of face. Arteries with warm blood give heat to veins with cold blood. Better for cold feet in cold temperature for these animals. Lose less heat if temperature of feet is closer to environment temperature. Ivory gull: most northern gull in the world. Tuck feet under feathers to keep feet warm. Arctic fox covering face with tale to keep face warm. Red fox has countercurrent heat exchanger in snout. Where a bird sleeps is important in dealing with cold.
