This year we spent most of September in Tanzania, starting in the island of Zanzibar and then moving to the mainland to visit some of the magnificent game reserves in the south of the country. The wildlife in these places is amazing! Insects, reptiles, birds and mammals all share this incredible landscape, so there is far more to see than just the so called ‘big five’. The birds, for instance, are fascinating, often very colourful and clever but weaver-birds must take first prize for dexterity and patience. The male is the main nest builder; he will weave a nest, using grass, leaves, twigs or reeds, which can take anything from two days to a couple of weeks to complete, depending on the species. It is an intricate structure, quite often over water, with the entrance pointing downwards to make it difficult for predators to steal eggs or chicks. Weaver birds are the only birds recorded to be able to tie knots; these secure the nest to reeds, twigs or branches. When the nest is finished the female comes to inspect and if ‘Her Ladyship’ doesn’t approve she will fly on to view other possible residences and the male will abandon or destroy his hard work and start again; he may build several nests before he attracts a satisfied female.
Another bird that occurs all over the savannah of sub-Saharan Africa is the Oxpecker. There are two species, the red-billed and the yellow-billed and wherever there are grazing or browsing animals you will see oxpeckers. They feed almost exclusively on the parasites that are on the animals, such as ticks and fly larvae and they will also probe open wounds for blood, often preventing the wound from healing.
One that plays host to the oxpecker is the Giraffe and the species that inhabits Tanzania is the Masai giraffe. There are four types of these elegant animals in Africa, with two of them having subspecies. This occurs when, usually because of geographical isolation, some animals develop different characteristics in appearance and or behaviour but are genetically the same as the original species. Giraffes live in groups usually comprising females with their offspring and close relatives, or bachelor herds but some males are solitary. When the males fight for dominance they engage in ‘necking’, not as we know it but by banging each other’s necks, sometimes quite violently.
The Giraffe is the largest of the ruminants, a group of herbivorous mammals which includes cattle, sheep, goats, deer and antelopes. Ruminants have four chambers in their stomachs each playing a different part in the digestion of the food. Initially the food is not chewed very much and it passes into the first chamber to be regurgitated into the mouth and ground up with the animals back teeth. This is what we call ‘chewing the cud’ and you can sometimes see a bolus of food travelling up the front of the animal’s neck. With the Giraffe it has a long way to go! Although the neck is long it doesn’t contain any more bones than different animals but each bone is larger than those of other mammals. The length of the neck gives the Giraffe the advantage of being able to feed on foliage that is way above the reach of other browsers and the tongue and upper lip are prehensile enabling the animal to use them to grasp the leaves when feeding.
The leaves of Acacia trees make up a large part of the Giraffe’s diet and one particular type of tree has a unique way of defending itself. It produces modified thorns, creating hollow balls which a species of ant finds ideal in which to nest; they also like to feed on the nectar that the trees produce. In return, and by way of rent, the insects will protect the tree from browsers, swarming over the nose and lips of any intruding animal; the ants also carry beneficial bacteria which help to reduce the amount of the harmful types that are present on the leaves of the tree. In all, a partnership that is a perfect example of symbiosis, where each organism benefits the other.
Even though Giraffes are big, powerful animals they are never the less preyed on by the large carnivores and the young and injured are particularly at risk. Leopards and Hyenas will hunt them but the main danger is Lions which work together to achieve a kill.
The Lion is the largest African predator and prefers to hunt the larger herbivores. As well as Giraffes lions will take Wildebeest, also known as Gnus, Zebra, Buffalo and the various species of antelope. They will take smaller prey, such as baboons and warthogs, but usually when bigger animals are not available. These big cats live in groups, known as prides, composed of females and their offspring and one or more males. Also, pairs of males, which are usually brothers, will live and hunt together. In a pride most of the hunting is done by the females which organise themselves so that some will place themselves in a position where the proposed prey animal can see them. As the lions advance, the victim becomes frightened and runs into the path of a hidden lioness which, with a short burst of speed, will dispatch the animal usually by asphyxiation, either crushing the windpipe or covering the mouth and nose with a tenacious bite. But they are not always successful so they also eat carrion or will steal the prey of other animals; Cheetahs, Hyenas and Hunting dogs often lose out to lions. Because they will sometimes not eat for a few days, even a week, they will gorge when they have the opportunity and then spend a lot of time sleeping to conserve their energy for the next hunt.
When a female is ready to give birth she will separate herself from the pride and will not take her cubs to meet the others until they reach 6 – 8 weeks old. As the lionesses tend to come into season at more or less the same time, all the cubs in the pride will be around the same age and will suckle from any lactating female.
Wandering males will be on the look out to take over a pride from the ruling males and serious fights ensue. If the intruder is successful he will kill the existing cubs and mate with the females. Life in the wild is raw.
One animal a lion will be very wary of is the Hippopotamus. Although a young one will be taken if it strays away from the adults, the lion would find a fully grown Hippo a serious adversary. They are large, aggressive animals which carry an impressive mouthful of teeth and they are easily capable of killing a lion, so they are only attacked by very hungry predators and then rarely; more people are killed by Hippos in Africa than by any other animal. This usually happens when canoeists get too close to the animals’ territory and as Hippos spend most of their time in water, and will lurk under the surface, they are often not seen until it is too late.
Hippos are herbivorous animals and feed on vegetation both underwater and on the banks. So why do they have such big teeth? The back ones are what you would expect for an animal with this sort of diet but the front ones are more like tusks and are used in defence when fighting others for territory or females and to attack predators.
We’ll continue our safari next month so meanwhile have a good Christmas!
© Sheila Sims 2017