BIG BIRDS

The ungulates like the wildebeest and the springbok seek shade in the heat of the day, but there is still activity in the riverbeds, as birds strut around. We often see the Ostrich ( Struthio camelus ) walking around. Unlike with the hyena, I can tell the difference between the sexes. The male ostrich has black plumage, while the female has rather drab, brown plumage. Ostriches are able to keep cool in the heat by fluffing out their feathers and spreading their wings. The male bird can weigh up to 150 kilograms, and their diet will often consist of tsammas and gemsbok cucumbers, and even insects and small reptiles. They are able to obtain moisture from their food, and therefore, do not need to drink often.

Ostriches do not mind the heat

Ostriches are able to breed throughout the year, but they usually lay eggs just before the rainy season. Several females lay up to thirteen eggs each in a hollow scrape in the ground. Only the dominant hen and her mate incubate the eggs in the collective nest. Only about twenty eggs are incubated, and surplus eggs are pushed aside, where they decay. The hen is able to recognise her own eggs, and these are retained. The male bird takes over incubation  during the night, and sits on the eggs.

 If danger threatens, an ostrich will feign a broken wing, in order to distract the predator, while the chicks are escorted to safety. An ostrich pair with a brood of chicks, may abduct chicks from another pair. Raising chicks does not take much effort as the chicks are able to feed themselves. One often sees chicks of different ages with one pair of adults, when chicks have been abducted. As ostriches are able to run up to sixty kilometres an hour for long distances, they are seldom preyed upon. The cheetah, which can run faster, is possibly their main enemy.

The ostrich is able to filter out salt from the water through glands near its beak.

Another big bird that is found striding in the riverbeds is the Secretary bird ( Sagittarius serpentarius ). A fully grown Secretary bird is often over a metre tall. Secretary birds often gather at midday at the water-holes which have sweet drinking water. It is one of the few birds that is able to carry water and food in its crop, back to the chicks on the nest. The Secretary birds pace up and down the riverbeds in search of insects, reptiles, rodents and eggs and chicks of smaller birds.The Secretary bird will also prey on snakes. The bird will dance around and dodge a snake until it is able to kill the snake by striking it repeatedly with its  claws and beak. They are usually in pairs, but large numbers, up to fifty birds, have been recorded at Rooiputs, Leeudril and Kij Kij.

The Secretary Bird

The ostrich is the biggest bird found on earth, and the Kori Bustard ( Ardeotis kori ) is the heaviest flying bird. The Kori Bustard can weigh up to nineteen kilograms. Kori Bustards do not often fly, and are more likely to be seen walking in the riverbeds. They are omnivores, and eat seeds, insects, and small rodents and reptiles. They are very fond of the gum produced by Acacia trees. Their alarm call is a barking sound. As the Kori Bustard is slow to take-off and fly, they are often the prey of caracals, jackals and leopards.

The Kori Bustard is listed as "vulnerable" on the Red Data list of birds.