Ilhéu de Curral Velho is a calcarous rock (0.5 ha), situated c.500 m off the southernmost point of Boavista and rising c.15 m above sea-level. The cliffs are heavily eroded and the extreme south-western part stands almost separate from the remainder of the islet. The islet is unvegetated, but fossilized roots of shrubs are plentiful. Due to the prevailing heavy seas, access to the islet is difficult and often impossible. The area on the opposite main island, centred around the deserted village of Curral Velho, consists of sand-dunes, a lagoon and an oasis with palm trees, Acacia spp. and Tamarix senegalensis. It has a typical arid-zone flora and fauna.
See Box and Table 2 for key species. There is a colony of c.100 pairs (1992 estimate) of Sula leucogaster on the islet. In addition, and more significantly, 2–3 pairs of Fregata magnificens breed amidst the boobies. The islet is one of only two breeding sites for F. magnificens in the Cape Verdes, indeed in the whole eastern Atlantic. There is also a small colony of Calonectris (diomedea) edwardsii. Puffinus (assimilis) boydi and Oceanodroma castro were reported to breed on the islet during the 1960s, but there is no recent information. A few pairs of Phaethon aethereus may still breed as the species was collected on the islet during the 1920s, and was observed again there on several occasions during the 1980s and 1990s. Birds breeding in the adjacent main island area include Falco (tinnunculus) alexandri, Coturnix coturnix, Cursorius cursor, Charadrius alexandrinus, Eremopterix nigriceps, Ammomanes cincturus, Alaemon alaudipes, Passer hispaniolensis and P. iagoensis. Although breeding of Pandion haliaetus was confirmed in 1986–1991, searches in 1998–1999 yielded no occupied nests. During migration periods, especially in autumn, the bushes in the area provide shelter to several species of Palearctic passerine migrants seldom encountered elsewhere in the islands.
Non-bird biodiversity: The sandy beaches of the Curral Velho area are important laying sites for sea turtles, in particular Eretmochelys imbricata (CR) and Caretta caretta (EN). Lizards occurring in the area include Mabuya stangeri and Hemidactylus bouvieri.
Pressure/threats to key biodiversity
The islet was designated a protected area by law in 1990, and may now only be visited under special permit, but in practice the law is difficult to enforce. Formerly, fishermen regularly visited the islet to collect the eggs and chicks of boobies (and, presumably, also frigatebirds) but, according to local informants, these activities have now almost ceased. This is probably due at least partly to the fact that the only other booby colony on Boavista, at Ilhéu de Baluarte, is easier to approach, and nest-robbery has continued to be more severe there. The adjacent main island area has been proposed as a protected area under the NPPAP. Its vegetation is heavily affected by the large numbers of goats that roam the area and, if protection is to be effective, it will need to be fenced off. An agreement has recently been developed between Cape Verde and Spain for major tourism development on the island of Boavista. This could eventually lead to increased pressure on this ecologically sensitive island and its surrounding islets, including Ilhéu de Curral Velho.
BirdLife International (2019) Important Bird Areas factsheet: Ilhéu de Curral Velho and adjacent coastal area. Downloaded from
http://www.birdlife.org on 19/10/2019.