Photographed as it was drying its wings in a tree, darters are a common sight in the Okavango Delta region. Widespread throughout sub-Saharan Africa and not considered to be endangered or threatened, the African darter (Anhinga rufa), is sometimes called the snakebird because of its habit of swimming with only its head and neck, snake-like, above the water.
African Darter drying out, Okavango Delta, Botswana. Canon 5D Mark 2 with 500mm lens at F6.3.
This bird can often be seen as pictured here, in a tree or on a rock drying its wings out. This behaviour is necessary because, unlike many other waterbirds, the darter's feathers do not contain oil and are not therefore waterproof. This lack of waterproofing means that the bird is less buoyant enabling it to dive more effectively for fish, however, it has the disadvantage that its feathers can become waterlogged hindering its ability to fly and also leading to a loss of body temperature.
Suggested further reading: Birdlife International
Further Botswana images are now online. ~KD.