CONSERVATION

CLIMATE CHANGE AND WILDLIFE

Climate Change and the Shape of Wildlife in Future

If the climate gets hotter, it can be expected that flamingos will need to lose heat, so more will be seen standing on both legs.

Will the safari-going tourist of the future find elephants with bigger ears or more flamingos standing on two legs? According to some scientists, it is more than likely if climate change continues to lead to hotter weather.

Animals need to maintain their body temperature between critical limits to avoid loss of normal functions or even death. Overheating can particularly affect the ability to carry out essential physical activities such as moving to areas where they can find food.

The two main ways of controlling body heat are evaporative heat loss, (for example by sweating with the water released being turned into vapour by body heat) and dry heat exchange (for example by the temperature of the blood being reduced in the presence of colder air.)

Many species release excess heat through selected body parts. It is well known that elephants flap their ears to cool down. Flapping sends colder air across a mass of veins near the surface of their ears to cool the blood. This is called thermoregulation.

There are two biogeographical “rules” that govern thermoregulation – Allen’s and Bergmann’s rules. Allen’s rule is based on the size of body appendages such as beaks, tails and legs. This suggests that larger appendages relative to body size provide a greater surface area from which to lose body heat. So, in warmer climates, larger appendages would be more of an advantage while being a disadvantage in cooler climates.

Bergmann’s rule is based on the size of the whole-body surface with the reduced body surface area to volume ratio of larger

BELOW Flamingos regulate their body heat through their legs. They shed heat by standing on two legs and preserve heat by standing on one leg.

APRIL - JUNE 2022 | 25