The African openbill feeds on snails and mussels - News - Gondwana Collection

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The African openbill feeds on snails and mussels

Avatar of inke inke - 16. January 2018 - Environment


Dirk Heinrich

The openbill, a species of stork almost sixty centimetres tall, delicately wades through the shallow water. Again and again it dips its head underwater. When it scoops up a freshwater snail it deftly pulls the animal out of its hard shell without breaking it. These birds need barely 15 seconds to accomplish that, but opening mussels usually takes a little longer. If a mussel cannot be cracked, the openbill drops it in a sunny spot on the riverbank where it will open eventually. Most of the time mussels are deposited in the same spot, which is easy to identify by the pile of empty shells. Currently such accumulations are found at the Chobe River Camp in the eastern parts of the Zambezi Region where openbills take advantage of the Chobe River’s low water level to forage for their favourite food.  

These birds depend on bodies of water to feed on snails and mussels and therefore they migrate extensively through the region, if need be. Openbill storks are a common sight at the Okavango, Kwando, Zambezi and Chobe during the annual counts of wetland bird species, says Holger Kolberg at the scientific section of the Ministry of Environment and Tourism. Water levels are always a decisive factor. When the huge pans in the Naye-Naye communal conservancy fill up with water they also attract large numbers of openbills. A total of 460 openbills were spotted at the Naye-Naye Pan in May 2000. In August 2011 the bird count yielded 930 openbills at Lake Oponono north of Etosha Pan and smaller numbers at Swakoppoort Dam and Von Bach Dam, and also at the Windhoek sewage plant.

In late September 2011 Dr Chris Brown discovered a breeding colony of some 3435 openbills at the Impalila-Kasane rapids in the Chobe River. Since it was not possible to count all of them from the boat, the total number is estimated to be around 5000. In over 40 trees along the riverbank alone 485 nests of this stork species were spotted. According to Dr Brown it was the largest openbill colony in southern Africa. Various species of water birds were also breeding there at the time. 

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