write any three adaptation of polar bear.
Answers
Answer and Explanation:
Polar Bear Adaptations:
Low surface area to volume ratio (anatomical) - Compared to other species of bears, polar bears have small extremities, proportionally shorter legs and a stockier build. This reduces the surface area to lose heat from. This is a common characteristic amongst animals that live in cold environments that enables them to retain their heat and conversely means they often can't cope with warm temperatures as they easily overheat in warmer temperatures.
Small extremities to reduce heat loss (anatomical) - Polar bears have small ears covered in thick fur, a very short tail and a relatively short and squat muzzle, all of which help to retain heat.
Polar bears eat a very high fat diet and have adaptations to allow them to process this food (physiological) - *This is possibly the key adaptation that polar bears have*. It enables them to eat the blubber of the seals that they catch which is the most energy rich and abundant part of the seal. Other animals could simply not survive if they ate so much fat in their diet. Adult bears often only eat the blubber while younger still growing bears will also eat the meat for protein.
Eating fat and not protein has another benefit in that it means the bear doesn't have to excrete excess nitrogen from the protein which being a mammal would be in the form of urea in the urine. Excreting urea requires an amount of water to be lost, while the bear could eat snow to replace this, it would use a significant amount of energy to warm the bear back up again, consuming fat simply avoids the problem.
Thick layer of body fat / blubber (anatomical / physiological) - This can be up 10 cm (4 inches) thick, it is used both for insulation and also for food storage to help survive when food supply may be intermittent especially in the summer months when bears often go hungry for long periods due to not being able to hunt their preferred food of seals. Up to 50% of a polar bears' weight can be fat! It also helps them to float naturally when swimming so avoiding having to use energy to keep their head out of the water.
Processing body fat to gain metabolic water (physiological)- Polar bears store a lot of fat which they use for energy in the process combining it with oxygen to release carbon dioxide and metabolic water. They live in a polar desert with little access to fresh water especially in the colder months (which are in the majority) in this way they can get extra fresh water - camels do a similar thing with their stored fat.
Thick camouflaged fur (anatomical) - The coat of the polar bear is especially thick and luxurious being the thickest of any bear (unsurprisingly!). There are two kinds of hairs, short soft dense inner hairs and longer stiffer outer guard hairs. The coat is the same colour all year round unlike some arctic animals which have a darker coat in the summer months. The coat usually appears to be perfectly white, though has a pale yellow tinge to it which becomes more pronounced in older animals. The colour of course provides camouflage against an icy and snowy background.
Thick fur on the paws (anatomical) - to insulate them from snow and ice and also provide for grip on slippery surfaces. The paws are large in size to help spread the bears weight over ice and snow and have blubber under the pads for extra insulation.
Maternity dens are dug into snowdrifts by pregnant females, these can have one to three chambers and provide protection from the cold and winds (behavioral) - The females give birth in the winter in these dens, twins are most common, the cubs stay with their mothers for over two years, around 28 months. The males have no part to play in the raising of the cubs leaving the females shortly after mating.
Pregnant females go into a kind of hibernation in their maternity den during the winter in which they give birth. (behavioural / physiological) - Males and non-pregnant females don't make dens and don't hibernate.
Polar bears are very strong swimmers (anatomical/behavioural/physiological) - They have been found in open waters 200 miles (320 km) from land and will readily swim long distances if necessary, though it is energetically expensive and young bears avoid swimming very far. They swim using their front legs in a manner where they reach out with the leg and pull at the water with their large paws, the back legs generally trail behind.
Polar bear liver contains a toxic amount of vitamin A that can cause severe illness or even death if eaten. This is not actually an adaptation admittedly but is interesting nonetheless. Husky dog liver is similar though not quite as toxic. So if you are ever starving in the Arctic and manage to kill a polar bear or husky, leave its liver well alone and go for the chitterlings instead
=The polar bear
Ans=thick layers of fat and fur - for insulation against the cold. a small surface area to volume ratio - to minimise heat loss. a greasy coat that sheds water after swimming - to help reduce heat loss. large feet - to distribute their load and increase grip on the ice.
I hope its helpful to you. ❣