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Unformatted text preview: Lecture 9 How winter-active endothermic animals avoid freezing from last class.- On cold days animals can BASK in the sun to try to stay warm o Basking can be done while sleeping o Turtles bask on logs and rocks- Shivering is an important means of THERMOGENESIS o Black-capped Chickadees lower their body core temperature by 12 o C. There is a less gradient and less heat is lost. However, bird cannot stay awake and enter a deep sleep called TORPOR (12hrs)- Other animals become inactive (dormant) – ie. Mink frog - For many animals, a body temperature of below zero is fatal (ie. Snakes because they are ECTOTHERMS) o They survive by FREEZE AVOIDANCE in a HIBERNACULUM (crack in the earth, so they are below the frost line)- All turtles (and bullfrogs) escape sub-zero temperatures by going to the bottom of ponds and lakes o American Toads (and many salamanders) dig beneath the frost line- But insects and other invertebrates for dormant ABOVE the frost line (ie. woolly bear caterpillars) o...
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This note was uploaded on 10/20/2011 for the course BIOL 1902 taught by Professor Runtz during the Fall '08 term at Carleton CA.
- Fall '08