The rehabilitation of Swift Terns Sterna bergii incapacitated by marine foam on Robben Island, South Africa

One-hundred-and-three incapacitated Swift Terns Sterna bergii were captured on Robben Island on 15 December 2003; 93 (90%) were released between 28 December 2003 and 4 February 2004, having been treated at the Southern African Foundation for the Conservation of Coastal Birds (SANCCOB) facility in Cape Town. The rehabilitation procedure is described. This is the first incident involving the admission of a large group of Swift Terns to SANCCOB and the first time birds have been known to be incapacitated by marine foam, generated by a combination of wave action, kelp mucilage and phytoplankton. Seven had been ringed as chicks; three were from Robben Island, three from other offshore islands of the Western Cape and one from Luderitz, Namibia, 855km to the north.