As the end of September now approaches, the dry season has really got its hold over the landscape. Vegetation is thin and water is scarce. Apart from a surprise downpour a couple of weeks ago, we haven’t had a drop of rain since April and aren’t expecting any for at least the next couple of weeks.
However, as I write this, the temperature outside is just shy of 38 degrees Celsius (100 degrees Fahrenheit). I am safely tucked away behind the walls and roof of my room, my is fan throwing a cool breeze across my face and I’m sipping on some ice cold water from the fridge.
But how do the animals out there handle the heat? Africa is known for reaching alarmingly high temperatures across the continent, temperatures which would leave us gasping with dehydration and sunstroke yet for the creatures out in the savanna, it’s just par for the course.
Firstly, you must know that when you visit us at Londolozi, particularly in the summer, we structure our game drives to be around dusk and dawn. This is partly for our own comfort as we wouldn’t enjoy being exposed to the midday sun ourselves, but it also happens to be the time of day that the animals are significantly more active.
Being out in the heat is energy sapping stuff and the animals avoid the heat of the day by lying up in the shade, retreating to an underground burrow (as with many nocturnal species) or – depending on the species and availability of water and/or mud – settle up in a wallow. This not only conserves valuable energy but also keeps the animals cooler. For some of the larger species like rhino and elephant which occasionally have to continue feeding through the day to sustain their large body weights, a healthy layer of mud over the skin can also protect their bodies while wandering about grazing in the midday heat.
Most animals are unable to perspire like we can (in fact, only primates and horses can sweat like we do). However, a similar process occurs by the action of panting. The moist membranes of the inner nasal cavities and mouths of several animals act as cooling surfaces for them. This behaviour is particularly noticeable with the predators and even our domestic dogs do it home. By drawing in large breaths repeatedly, the animals pull a breeze over the inner membranes of the nose and mouth which, because of the saliva and mucus covering them, cools the blood beneath. Interestingly, birds are also known to ‘pant’ in a behaviour known as gular fluttering and can be often seen when a bird simply stands still, bill open with their throat gently fluttering.
Some animals take on a slightly less conventional method to cool themselves. Birds are an example of one of the animals that cannot sweat and so, in order to cool off in a similar fashion, they instead defecate on their legs and feet. The moisture of their faeces cools over their skin and acts the same way as sweat does for us humans, bringing our body temperature down through evaporative cooling. A great example of this is seen in the stork family which – given the fact that they have exceptionally long, exposed legs – works rather well for them.
Ostriches are known to inhabit some of the hottest and most arid regions of Africa and have therefore also adapted a unique method to keep cool. While their wings are far too small to lift their heavy bodies off the ground, they do however have a bare patch of skin beneath them. When exposed, particularly to a combination of shade (provided by the raised wings) and a slight breeze (provided by the elements or even the wings themselves), the ostrich’s body is immediately cooled. This explains why ostrich will often walk about feeding in the heat of the day with their wings stretched wide open, occasionally flapping to fan themselves.
These are just a few of the simple ways that some of the animals of the African savanna have adapted or behave to survive the scorching temperatures of the region. As effective as some of these methods are, we can’t help but be grateful for the air-conditioning system and ice cold drinks that we enjoy by the plunge pool on the hot summer days!