They are often seen over the reserve soaring in numbers and particularly when food is available in the plains area. They are one of the heaviest soaring birds in the southern African region with average body masses ranging from 7.3 - 10.3 kg (second only to White Pelicans which can weigh up to 15kg).
These birds are specialist scavengers and along with the white backed have lost the complete ability to grip prey with their feet unlike soem of the other speices found in our area. They feed quickly and can fill their crops in 2 minutes, competition is fierce and together with feeding quickly their serrated deeply troughed tongues aid in consuming as much as possible in as short a time as possible.
Cape and White backed vultures outcompete other scavenging birds in numbers and are more often than not the first to arrive at kills preceeded by Bateluers and the smaller vultures.
There numbers are stable in most areas of their core range but as a result of the endemism these vultures are threatened by habitat loss, breeding site destruction as well as human encroachment onto core ranges. The success rate of chicks reared to flying age is lower than most other afrotropical species with only 43% of clutches reaching flying age.
Most hornbills, of which there are three to be found in the area (yellow-billed, red-billed and grey hornbill), build their nests in natural tree holes and they do it in a very unusual manner. Once a suitable hole is selected, the female seals herself in with mud provided by the male. This plug serves as a good predator deterrent and helps prevent nest take-overs by other hole-nesting birds. The female incubates her eggs while being fed by the male through a narrow slit left in the plug. Once the chicks have hatched and are old enough to accept food, the female breaks out and the entrance is re-sealed by the chicks. The adults then feed the chicks through the slit until they fledge.
Honeyguides relish honeycombs and are thought to be attracted by the smell of wax. This was first noted as early as the 16th century by a Dominican missionary in Mozambique, who noticed that honeyguides were eating wax from the altar candles. Once a honeyguide locates a beehive, it usually sets out to find another animal, i.e.: a honey badger that might be able to open up the beehive and expose the honeycomb and bee larvae. It would then guide the helper by calling repeatedly and flying in the direction of the hive. Their tough skin give them some immunity to bee stings and they also carry highly specialized bacteria in their gut that makes them the only birds in the world able to digest beeswax.
In some owl species, the ears are positioned asymmetrically in the skull, with the left ear higher than the right. This unusual ear arrangement is thought to help the owl localize sound, and accurately detect the position of its prey in the dark. Some, such as the Barn Owl, have movable flaps of skin next to their ears that they can move and adjust to improve the detection of sounds coming from any direction.
While most waterbirds trap a layer of air between their contour feathers to help them float, cormorants and African Darters, on the other hand, intentionally raise the feathers on their bodies when swimming, which allows water to flow between their feathers and soak them. The low buoyancy means that they can remain submerged for longer periods of time, and can dive further in search of food that other waterbirds would be unable to reach. When they emerge, their drenched plumage needs to be hung out to dry, a process that also warms the bird after its swim in cold water.
The Burchell’s Coucal is called the “rainbird”, as it often calls before, during or after rain, emitting a series of rapid hooting notes that sounds like water bubbling out of a narrow-necked bottle.
The Black Heron has evolved its own highly specialized fishing method by casting an umbrella-like shadow over the water with its wings spread. It is thought that this has the dual purpose of helping to shade its eyes from the glare of the sun, as well as attracting fish to the shady spot created underwater.
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