So basically, desert lizards adapt to the weather by altering their colours (depending upon the ambient temperature), by basking in the sun to absorb heat in the mornings, or by seeking shelter to avoid heat. Thus, it is clear that this species requires behavioural adaptations (seeking shelter from heat and the ability to change colours depending upon the ambient temperature) in order for it to regulate the temperature in their bodies.
Blue-tongued Lizards (in New South Wales):
Blue-tongued lizards don’t produce their own body heat and thus rely on their surroundings for body temperature. They maintain a body temperature of about 30-35° c when active. When the ambient temperature is low (cold), blue-tongued lizards stay buried deep in their shelter sites and remain inactive. As like the desert lizard, blue-tongued lizards emerge to bask on sunny days.
Blue-tongued lizards adapt well to the suburbs where there are large backyards with plenty of shelter. They often use the various shelters to avoid heat when there is a need, only to resurface when they need more heat. This behavioural adaptation helps assist the blue-tongued lizard’s temperature regulation while at the same time being adapted to human activity.
Examples of endotherms:
The red kangaroo (lives in Australia’s arid regions):
The red kangaroo has various means of regulating body temperature. The fur and body fat helps this mammal to stay warm. Also, the light colour of the fur helps it to reflect heat. During the high ambient temperatures (when it’s hot), this mammal avoids the heat by seeking shelter, and by licking its forelimbs to increase heat loss by evaporation of water. In addition to this, the red kangaroo also pants and sweats so that it can cool down (as a response to heat). Apart from this, the red kangaroo reduces the surface area exposed to the sun on a hot day by altering its posture (where the tail is pulled into the shade of the body, while the body slightly curls up) as well.
So, the red kangaroo adapts to heat by the behavioural characteristics of: seeking shelter; panting and perspiration; licking its forelimbs to increase heat loss by evaporation of water; and by slightly curling up their bodies and hiding their tail to minimise the surface area exposed to the sun. The structural characteristic of a light coloured fur helps this mammal to reflect some of the heat given off by the sun, thus helping it to maintain body temperature (by helping it keep cooler on a hot day). For cold temperatures, this mammal does not need to worry as it has its fur and body fat for warmth. Also, the red kangaroo migrates to a warmer area if there is a low ambient temperature. Therefore, it is clear that this mammal adjusts to the ambient temperature by using various methods (for reducing heat, or by migrating to avoid cool temperatures).
Mountain Pygmy Possum (lives in the alps of Victoria and N.S.W.):
The Mountain pygmy possum is nocturnal meaning that it avoids ambient temperatures during the day by restricting itself to sleeping curled up in a ball to retain heat. Apart from curling up, this mammal also keeps warm due to its fine and dense fur. The mountain pygmy possum inhabits what could be described as a boulder field (repeated wetting and freezing of water on rock surfaces have resulted in the fragmentation of boulders, thus creating the boulder field). So this habitat also helps keep this mammal cool during the warmer days.
Thus, the mountain pygmy possum regulates its body temperature by avoiding the ambient temperatures experienced throughout the day, while at the same time retains heat by sleeping curled up as well as keeps warm despite the cool surroundings due to its dense fur. So the behavioural adaptation of it being nocturnal and the structural characteristic of having a dense fur help it to regulate its body temperature. This mammal doesn’t really display responses to the ambient temperature of the environment, except for perhaps curling up to sleep to avoid throughout the day.
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