Animals are Either Warm Blooded or Cold Blooded.What Does It Mean to be Warm Blooded or Cold Blooded?By Moira Whitehouse PhD
Being warm blooded The body temperature of a warm blooded animal stays about the same no matter how cold or hot it is outside.On a sunny, hot day a warm blooded animals’ body temperature is the same as it is on a cold, snowy day . A warm blooded animal manages this by using (burning) the food it eats for energy to keep its body warm. Warm blooded animals also have special ways to keep their bodies from getting too warm.
Birds and Mammals are warm blooded, andso are we. Our body temperature staysabout 98.6 degrees F when we are healthy.If our temperature gets much above orbelow that, it might be a clue that we aregetting sick.For example, while playingoutside on a hot 108°Texas day, your temperaturewould be about 98.6 degrees F.
And even while making asnowman on a very coldday, your temperature wouldstill remain the same --about 98.6 degrees F.
Bears are warm blooded mammals like us.Their body temperature stays at about 90degrees F in both cold or hot weather(except when they are hibernating).
Other warm blooded animals also havebody temperatures that remain constantregardless of the outside temperature.Dogs and cats temperatures vary between100.5 and 102.5 degrees F.
A whale’s temperature stays at about98.6 degrees F in icy cold water and inwarm tropical water as well.
A bird’s temperature is alwaysabout 105 degrees F no matterwhere it lives-- in the cold Arcticor the hot rain forest.
All animals change some of whatthey eat into mechanical energyused for movement. Warm bloodedanimals also use some of theirfood to create heat for keepingtheir temperature constant.
Being cold bloodedThe body temperature of cold blooded animals, such as reptiles, amphibians, and fish, becomes warmer or cooler as the temperature around them changes. On a cold winter night, their body temperature falls.
On a hot day in the summer, theirbody temperature goes up.
A frog is an amphibian, and therefore is coldblooded. His body temperature is about thesame as his surroundings. If it is 40 degrees Foutside, his body temperature is about 40degrees F and if it is 95 degrees F outside, hisbody temperature is about 95 degrees F.
In hot environments, the temperatureof a cold-blooded animal could bewarmer than the temperature of awarm-blooded animal.Cold-blooded animals are muchmore active in warm environmentsbut they are very slow moving andsluggish in cold environments
So that we can see the difference in warmand cold blooded animals we will use aninfrared light, like this one, to view a warmblooded person and a cold blooded animal.
In infrared light, warm objects showup as warm colors: reds, oranges andyellows.Cool objects show up as coolercolors: blues, greens and blacks.On the next slide you will observe infraredphotos of a person holding a cold bloodedlizard.Notice the the colors of the lizard and frogimages and compare them to the image ofwarm blooded human holding them.
Both the frog and gecko appearas a darker color than thehuman. That means their bodytemperature is colder than thehuman’s. This is because theyare cold blooded and would bethe same temperature as theroom, whereas the human’stemperature is always warm.
Here we see a the hand of a child as he plays witha pet snake. It is pretty easy to see which iswarm and which is cold blooded.
This lizardhas movedinto thesunlight toget warm. Just as he moves into After he sits in the sunlight the sunlight for a few minutesNotice how his body temperature rises as he basksin the sun. (Compare picture 1 and 2)
Turtles are reptiles and are cold-blooded. They spend much of their lives in water and will bask in the sun on warm days. When the weather turns cold, turtles will often burrow into the soil until warm weather returns.These turtles have just walked out of pool of cool water. Notice how cold they still are. Notice how warm this turtle has become after basking in the sun!
From our study of animal needs, wemight remember one of a warm-bloodedanimal’s needs is to keep its body at acertain temperature.If the body temperature gets too high orlow, an organism will likely be sick andmay even die.
If your temperature is higher than 100degrees F or lower than 93 degrees F, itprobably means that you are sick.
The range of body temperatures for acold-blooded animal is much greaterthan for a warm-blooded animal.However, if their temperature getsoutside of that range, too hot or toocold, they will also die.So the body temperature of an animalin either group, warm or cold-blooded, has to stay within a certainrange.
One of an animal’s basic needs is to keepits body in the right temperature range.But how do they manage that, how dothey keep warm or cool?How an animal keeps its temperature atthe right level mainly depends on whetherit is warm or cold-blooded.First, we will look at how warmblooded animals stay cool when thetemperature outside gets above theircomfort level.
To cool off many warm-blooded animals use theprocess of evaporatingwater.When water evaporatesfrom the animal’s body itabsorbs heat energy andcools the animal’s body.This is why you feel socold when you get out ofthe swimming pool on ahot summer’s day.
One way warm blooded animals keep theirbodies at a constant temperature in hotweather is by panting. Fast moving air overthe animal’s tongue evaporates watercooling the tongue and the animal.
Animals like pigs wallow in mud when theyare hot. The water evaporates and lowersthe pig’s body temperature.
Some mammals sweat bead of sweatwhen they get toohot. Primates, such ashumans, apes andmonkey, have sweatglands all over theirbodies. Dogs and catshave sweat glandsonly on their feet.How would sweatingcool an animal?
Mammals who live in water like whalesdon’t need sweat glands. To cooloff, they simply swim to a cooler spot inthe ocean.
Many mammals and birds that live inhot climates avoid the summer heatby coming out to look for food atnight when it is cooler. Theseanimals are called nocturnal.
Big cats such as jaguars and cheetahs arenocturnal. They keep cool by lounging inthe daytime and hunting at night. Duringthe day, they rest under the shade of a bigtree.
Some mammals who live in hot climateslose heat through their big ears.
Even Sooty Tern chicks know to get in theshade of a bigger bird (a Black FootedAlbatross) when it gets too hot.
Like cats and dogs, birds also pant to get ridbody heat. But it is not throughevaporation that they lose heat. Theybreathe very quickly, letting the cooler airpass through their lungs which carries heataway from their bodies. A bird standingwith its mouth open on a hot day isprobably panting.
So mammals and birds, the two groupsof warm blooded animals, have manydifferent ways to keep cool. Can youremember some of them?Now let’s consider how warmblooded animals keep warm whenit is cold outside.
Land mammals thatlive in cold placesoften grow a thicklayer hair or furduring the winterthat keeps the heatinside their bodies.Their fur or hair actslike a blanket.
In the summer when the weatherwarms up, these animals lose thatthick layer of hair or fur.
Whales and walruses live in coldocean water and have a layer ofblubber (fat) to keep them warm. whale blubber
A polar bear has both a thick fur coatand a layer of blubber (fat) whichinsulate its body.
A bird’s feathers, like the mammal’s hairand fur, provide remarkable insulationfrom the cold. Many birds grow extrafeathers in the fall to keep them warmerin the winter. They lose this feathers comespring.
Some birds cannot survive cold winter weather.These species migrate to locations withwarmer temperatures and more food. bird migration routes
Some warm blooded mammals such asground squirrels, bears and bats cope withthe cold by hibernating, a deep wintersleep. In the fall, these animals eat a lot of food which they store as fat.
When cold weather comes mammals thathibernate find shelter in places such as holes inrocks or caves.When hibernating, theanimal’s body temperaturedrops, and both itsheartbeat and breathingslow down. It uses hardlyany energy to stay alive.This is when the animallives off the stored fat thatwas packed on in the fall.
Some mammals and birds that live in verycold climates huddle together to keepthemselves warm.
So far we have talked about how warm-blooded animals keep themselves warmwhen their environment is cold and coolwhen it is hot.But what about cold-blooded animals?What do you remember about cold-blooded animals and how they aredifferent from warm-blooded animals?
Cold blooded animals, you shouldremember, have a body temperature thatis the same as the temperature in theirsurroundings.To warm or cool their bodies, they mustchange their surroundings.
Reptiles like lizards, turtles and crocodiles baskin the sun to warm up .After a cool night, lizards, turtles and snakesclimb on to a rock or log where they lie in thesun which warms up their body.
When the day warms up and a reptile becomestoo warm and needs to lower its bodytemperature, it finds a shady area under arocks to cool down or log or slips into the coolerwater.
Reptiles like lizards and snakes that livein the hot desert stay in undergroundburrows during the hot summer days lcoming out at night to hunt for foodwhen it is cooler.
Amphibians like frogs and toads use the sametechniques to warm up and cool down.In the spring andsummer they lie onthe bank of a lake orriver absorbing therays of the Sunthereby warming uptheir bodies. When they need to cool down, they slip into the cool water.
They may also simply swim into thewarmer top layer of water in a pond toheat themselves up a bit. When they gettoo hot, they typically move to a coolerplace, sometimes even going underground.
But how do reptiles and amphibiansstay warm in places where thetemperature drops below freezingduring the winter time.Generally during the winter, theyburrow underground and hibernatebelow the level that the groundfreezes. Their heart rate andbreathing slow down. When springcomes they emerge.
Here we see where snakes and lizardshave gone underground into burrowsor caves to keep away from the freezingtemperatures.
One amazinghibernation storyis the GarterSnakes ofManitoba, Canada.Thousands of Red sided garter snakes enterlimestone caves to seek shelter below thefrost line in an area that can experience harshwinter weather. This is the largest gatheringof snakes anywhere in the world.
When the cold weather comes duringwinter, frogs, toads, and river turtles burythemselves in mud or soil and “hibernate”. Inthe spring when the sun warms the mud, outthey cometo absorb the heat of the Sun.
Some frogs that live in very cold placescan’t dig down far enough into the soil toavoid the ice and actually freeze duringthe cold winter months.When the weathergets warmer, the Frozen frogfrog’s body meltsand after somerepairs to its bodycomes alive.
What about the other cold bloodedgroup of animals—fish?For fish it is easy—they just swim toa layer of the water where thetemperature is right for them.Fish who live in areas where thewinters are cold move to deeperwaters during the colder months ormigrate to warmer waters.
So remember that if an animal is tosurvive, it must keep its bodywithin a certain range oftemperatures.If its body temperature becomestoo high or too low, an animal willbecome sick or die.
•In this presentationwarmhave The differences between we and cold-blooded animals. discussed the following points:• How warm-blooded animals keep warmwhen it is cold outside.• How warm-blooded animals cool downwhen it is hot outside.• How cold-blooded animals warm up whenit is cold outside.• How cold-blooded animals cool downwhen it is hot outside.• How cold-blooded animals survive coldwinter temperatures.
Let’s go back over each point and seewhat you can remember.What is the difference between a warmand cold blooded animal?What two animal groups are warm bloodedand which three are cold-blooded?
• How do warm-blooded animals (mammalsand birds) keep warm when it is cold outside?
• How do warm-blooded animals (mammalsand birds) cool down when it is hot outside?
• How do cold-blooded animals warm upwhen it is cold outside? Cold-bloodedanimals include reptiles such asturtles, lizards, snakes, crocodiles andalligators, amphibians such as frogs and toadsand fish.
• How do cold-blooded animals cool downwhen it is hot outside? (Cold-blooded animals include reptiles such as turtles, lizards, snakes, crocodiles and alligators, amphibians such as frogs and toads and fish.)
• And lastly, how do cold-blooded animalssurvive cold winter temperatures?