Biology 3660A/B Lecture 25: 3601 Lec 25.docx

• School: Western University
• Department: Biology
• Course: Biology 3660A/B
• Professor: Brent Sinclair

Document Summary

Insectivores: many rodents, bears, many temperate bats, raccoon dog, fat tailed dwarf lemur, pygmy possum, echidna. Phases of hibernation: plant a temperature probe in the squirrels body, body temperature drops from 35c to 5c, entrance phase functions as an ectotherm at this point, arousal temperature goes up again, torpor body temp and metabolic rate is very low, period of shivering when waking up to generate body heat, a lot of brown adipose tissue. Eat a lot more unsaturated fatty acids: experiment fed different amount of different fatty acid diets, they need a polyunsaturated rich diet to do torpor, if not enough fatty acids = no torpor, saturated membranes = higher energetic cost, homeoviscous adaptation. Arousal: thermogenesis followed by shivering, huge increase in metabolic rate associated with arousal, extremely expensive, up to 80% of entire winter energy costs, done because, to pee nitrogenous waste, increase gfr, accumulation of waste during hibernation.