The status of seabirds at Latham Island, Tanzania

Abstract

Latham Island, Tanzania, was surveyed in August 2004 — the first known survey of the island outside the period October–March — and in December 2005. On both surveys, four species of seabird were breeding at the island. Larger numbers of swift tern Sterna bergii thalassina and common noddy Anous stolidus plumbeigularis were breeding in August than in December, but the converse was true for masked booby Sula dactylatra melanops and sooty tern Sterna fuscata nubilosa. The estimated breeding populations of the four species were: masked booby (3 700 pairs), swift tern (320 pairs), sooty tern (4 400 pairs) and common noddy (4 000 pairs). These represent about 20%, 50%, <1% and 25% respectively of the overall populations of these subspecies. Information is presented on moult, measurements of birds, eggs and nests, and on the construction and densities of nests. The plateau of the island was not substantially modified by the Indian Ocean tsunami of 26 December 2004, but the structure of the surrounding beach changed noticeably between the two surveys. In December 2005, few carcasses or skeletal remains of seabirds were seen and the large numbers of boobies and sooty terns breeding then suggest that populations of seabirds were not greatly reduced by the tsunami of 2004.

Keywords: Anous stolidus, common noddy, Latham Island, masked booby, Sterna bergii, Sterna fuscata, Sula dactylatra, sooty tern, swift tern, tsunami

African Journal of Marine Science 2006, 28(1): 99–108