Giraffe Day

Wednesday, 4th March

First thing this morning before our lecture started, we walked 10 minutes into the bush on Chiwawe side (the half of the reserve where our camp is) to witness the family of four black rhino feed, including baby Khanya! It was such a special experience to see all four rhino so close together, as usually they are solitary animals. Never before have I sat in silence for 40 minutes simply watching and being so mesmerised and unaware of the passing of time. Eventually they finished feeding and we headed back to camp to begin our lecture on biomes of Southern Africa.

In the afternoon we had an introductory tracking test, which included a monitor lizard's spoor and a 'track' that was in fact made by a blade of grass blowing in the wind, fooling us all. It seemed mind boggling how tiny details in spoors can make all the difference in distinguishing one animal from another, however Sam (one of our instructors) reassured us that it comes naturally with practice and experience.

We also had a close up encounter with a herd of giraffe by some miombo woodland (the dominant type of woodland in Zimbabwe, a mixture of msasa and mnondo trees). If not the most intelligent, they are certainly one of the most inquisitive of the African animals. They came right up to our vehicle and surrounded us, giving us a blissful half an hour or so surrounded by these awkwardly elegant but beautiful creatures.

They have dark blue-grey tongues in order to prevent sunburn, as they spend so much time with them out of their mouths, picking off leaves and twigs. The Shona word for giraffe is furira mudenga, fittingly meaning 'eating from the sky'. The social structure of giraffe is known as temporary association, in which there is no patriarch or matriarch but instead a group that regularly fluctuates in number. Though not territorial, bulls periodically move from association to association in search of mates and often end up fighting to win a female in heat. Mature males can be distinguished from females by their exposed ossicones (horns), balded by such fights which can also determine hierarchy among juveniles in a group.

Another fascinating fact about giraffe is that, despite standing up to 6 metres tall, they have the same number of vertebrae in their neck as we do: 7. They are the tallest land mammals and are the largest of the ruminants; just like cows, they spend much of their time chewing cud and metres-long strands of saliva can be seen blowing in the wind from their lips. Lovely.

Like all prey animals - though it is very rare for a fully grown giraffe to be victimised due to their size and ability to dole out vicious kicks - they do not sleep for long, around 4 hours at a time and never fully lying down. If they were to lie down, all the blood would rush to their head and cause them to pass out and eventually die. To overcome this problem when they drink, giraffe have evolved three special adaptations. Firstly, giraffe spread their legs when they drink, therefore lowering the level of the heart so the height difference between head and heart is diminished, reducing excess pressure on the brain. Secondly, there are many valves in the jugular veins leading away from the brain to prevent the backflow of blood. Lastly, a spongey tissue known as a 'wonder net' is located at the base of the brain through which arterial blood flows and is thought to control the entry of blood into the brain when the giraffe bends down, reducing an otherwise fatal pressure. In addition, the lymphatic fluid surrounding capillaries is thought to have an effect much like a G suit worn by fighter pilots; it acts as a counter-pressure to prevent rupture of capillaries. This, as well as the fact that giraffe have the thickest artery walls of any mammal, ensures that they don't bleed to death while their bodies transport blood such long distances.

To top it all off, on the way back home we saw a mating pair of Verreux Eagle Owls, the largest of the African owls and, as the name suggests, about the size of an eagle. What is hilarious about these otherwise fairly scary creatures is that their eyelids are bright pink, giving them the effect of eye shadow!