Tinhosas Islands – desert island, seabird paradise
São Tomé e Príncipe is a small tropical country known amongst birdwatchers and conservationists for its endangered secondary forests, and high level of bird endemism. However, the country also holds the most impressive seabird colonies in the eastern tropical Atlantic Ocean - the Tinhosas Islands. These are two barren rocky islands around 12 km SW of Príncipe Island. They are named Tinhosa Grande, and Tinhosa Pequena, and are both remote and endowed with abundant seabird life. Three of five seabird species known to breed in São Tomé e Príncipe, namely Brown Booby Sula leucogaster, Sooty Tern Sterna fuscata, and Black Noddy Anous minutus, breed in Tinhosas, some in great numbers. The last assessment of the Tinhosas colony was completed in 1997, and since then accounts of exploitation of the birds for human consumption have raised concern about its conservation status.
BirdLife International sponsored a two-day expedition to Tinhosas islands, in order to conduct a census of breeding birds, and assess trends and threats. "We departed for Tinhosas in a quite misty dawn, and saw few birds en route, but seabird numbers increased massively as we approached Tinhosa Pequena. They were mostly 'Wideawake' Terns [Sooty Terns]", said Nuno Barros, SPEA/BirdLife Portugal seabird officer, and one of the participants in the expedition. When on the scene, and after two days of seabird census in intense tropical heat and a night spent amongst large numbers of land crabs, the results showed that while some species registered a slight increase, others, like Brown Booby evidenced a steep decrease from the 1997 census figures. “Caution must be used when interpreting these differences, for multiple visits within and between years should be performed, to census breeders, monitor threats and establish breeding phenologies" says Simon Vale, a PhD student at Manchester Metropolitan University, based in Príncipe at the time, and also an expedition member. “Nevertheless, the massive decrease in Brown Booby numbers is a grave concern.”
Tinhosas islands are an amazing wildlife spectacle, and a remote arid paradise for breeding seabirds, that deserve further investigation and safeguarding. As Dr Ross Wanless, team member and Africa Coordinator for the BirdLife International Marine Programme, explains “Although none of the species breeding there is globally threatened, this is the only seabird colony of any significance in the Gulf of Guinea, so assessing the populations’ health and protecting the colonies from human impacts is of great value."
BirdLife International and the expedition team would like to thank Bom Bom Island Resort for logistical support for the expedition. Ross Wanless received some financial support for the expedition from the University of Cape Town.