By Hugh Chittenden
This note deals with one of the most interesting aspects of Korhaan biology which is their habit of using throat feathers in display, especially while calling. The ‘black’ Korhaans are better known for their aerial cruises while calling and are not included here.
The throat patches of the four species included in this note are usually inconspicuous and not very noticeable in field until they start calling, or displaying. Then the throat feathers are raised and they become conspicuous and noticeable even from a considerable distance away.
Karoo Korhaan
Karoo Korhaan is the most cryptically plumaged within the southern African region, and it has a most striking and conspicuous black throat patch (when extended), which it uses to great effect.
Below: An inconspicuous male Karoo Korhaan at home in its preferred habitat, the Karoo shrublands.
Below: With heads lifted high and throat feathers puffed out, these birds stand out well when calling in the Karoo shrublands. The female (in the foreground) has a less expansive black throat patch, and a more conspicuous white border below. Males sometimes call alone, but duetting is more common in territorial maintenance.
Below: A female calling. On a still day the far-carrying frog-like call of this species can be picked up kilometers away. When one pair calls, other birds in the vicinity, answer in an echoing fashion in the surrounding hills!
Blue Korhaan
Below: Skulking and secretive, Blue Korhaan is the most colourful of the four species.
Below: The male is preparing to answer the territorial call of birds in the distance.
Below: The protruding throat of a calling male.
Rüppell’s Korhaans
Below: Rüppell’s Korhaans, occupy arid and semi-desert habitats, so are relient on their cryptic plumage to blend into the surroundings for camouflage.
Below: Male and female Rüppell’s Korhaans.
Below: Two different males calling
Below: A male neck and throat fully extended to achieve maximum volume!
White-bellied Korhaan
Below: Typical grassland habitat occupied by this species.
Below: Left: Male Blue Korhaan calling. Right: Female responding to call, with throat feathers extended.
Below: A Male Blue Korhaan prominentlly displaying his headware!
Acknowledgments: Derek and Wendy Coley, and Graham McGill are thanked for contributing their excellent photographs. Photos not credited, are those of the author.
