11 30 09 SI A Ecl 365 Behavioral adaptations to environments 1 What is torpor a Physiological state in which energy expenditure is greatly reduced by decreasing body temperature and rate of metabolism 2 When does Torpor occur a Occurs when environmental conditions exceed an individual s capacity for homeostasis b e g harsh climate or food water shortage 3 What is another term for torpor a Dormancy 4 What vertebrates become torpid or dormant a Regular cycles of dormancy are major features of herp lifestyles especially in extreme environments b Among endotherms many small to medium sized mammals and some birds abandon homeothermy daily or seasonally 5 How are ectotherm and endotherm torpor different a Ectotherms do not regulate body temperature during torpor and cannot awake arouse b Endotherms regulate body temperature during torpor albeit at low levels and can awake arouse 6 The types of torpor are torpor and torpor a Daily and seasonal 7 How often can daily torpor occur a Daily Everyday 8 What are two types of seasonal torpor a Hibernation winter b Estivation summer 9 How is daily torpor beneficial a Saves energy during the inactive period of the day b Lasts only a few hours 10 What types size class animals experience daily torpor a Small mammals and small birds 11 Why do small mammals birds utilize daily torpor a Fast use of energy poor reserves b Variable food insects nectar resources 12 In daily torpor the body temperature falls C below the animal s normal temperature Also oxygen consumption is less than to of the normal consumption rate a 5 15C below normal temp 1 3 to 1 40 13 Describe what happens during winter torpor or hibernation a Body temperature Tb can be reduced to within 1 degree or less of ambient temperature Ta b O2 consumption markedly reduced c Heart rate markedly reduced d Prolonged periods of breathing apnea e Body slows down much more than in sleep 14 What is the only known avian hibernator a Common Poorwill 15 What types of mammals hibernate a Carnivores bears badgers b Rodents many e g woodchucks chipmunks ground squirrels dormouse hamsters c Insectivores e g African shrews golden moles d NA bats some species 7 migrate others 9 hibernate e Smaller marsupials 16 What factors induce hibernation a Cold weather b Low food supply c Increased fat d Increased serum magnesium levels e Change in respiratory control center sensitivity to CO2 17 Describe the three steps to entering hibernation a 1 decrease in heart rate breathing rate b 2 drop in oxygen consumption c 3 drop of body temp 18 True False A sudden drop in temperature results in deeper torpor in hibernating species a False they wake up 19 At what temperature are arctic ground squirrels either frozen or awake a 15C 20 True False Hibernation is a continuous torpid state for months a False there are periodic arousal periods 21 True False In all mammals that hibernate arousal takes about the same time a False time needed differs among species larger take longer etc 22 Hibernation arousal is an process involving a high rate of production fat tissue generates heat during the early stages of arousal a Active heat brown 23 What are the stages of hibernation arousal 3 a Increase in heart rate b Increase metabolism c Reset temperature regulating mechanism 24 Since arousal from hibernation takes a lot of energy it is equivalent to the energy used in 10 days of hibernation why do animals wake up a Eliminate build up of N wastes b Restore water lost by evaporation c Fat storage depletion 25 Where do herps usually spend winter a A place where Ta will not dip below freezing b Bottom of lakes usually 4 C mud water c Terrestrial hibernators usually find sites below frost line d Snakes ball up in communal dens this does not keep them warm but may reduce water loss e Many herps rest on bottom of water body not in mud increasing cutaneous respiration f In mud must switch to anaerobic respiration have high lactic acid tolerance g Common to find turtles swimming under ice 26 Freezing is not lethal to herps a False it is they can withstand brief periods of supercooling 27 How do ice crystals physically damage cells and tissues when the animal freezes a Intracellularly dehydrates cells raising osmolality b Extracellularly blocks O2 and nutrient flow 28 What happens when freeze tolerant herps are frozen a Heart stops metabolism stops no brain activity detected for up to 2 weeks in frozen wood frogs b Vital functions return within 1 2 hours of thawing 29 What is cryoprotectant a Antifreeze inside cells cryoprotectant glycerol and or glucose 30 What happens to extracellular body water when herps are frozen a Extracellular body water becomes ice this can be up to 40 60 of total water in body 31 What is estivation a Seasonal torpor summer torpor b Less severe depression of core temperature and metabolic rate c Generally in response to drought or extreme heat d dehydration would occur quickly 32 What animals estivate a Amphibians in desert face long periods of low humidity and no rain b Lungfish in S America Africa also estivate c Some desert rodents estivate d e g cactus mouse mohave ground squirrel 33 What is a benefit or torpor a balance the energy budget in extreme environmental conditions 34 What are costs of torpor a animal is helpless little or no growth reduced reproductive period 35 True False Torpor is a last resource when animals cannot deal with environment in a better way such as insulation or migration a True