Ilhéu Raso

Raso is an uninhabited 7 km² volcanic island in the Barlavento archipelago of Cape Verde. Razo is an old name for the island. It is flanked by the smaller Branco islet to the west and by São Nicolau island on its eastern side.

Environment

The island is a stratovolcano some 3 km long by 2.4 km wide, reaching a height of 164 m above sea level. It is approximately 123 million years old and was formed from even older oceanic crust. The south-western part is a dry, boulder-strewn plain. There is little vegetation apart from an area of grassland in the south-west. The entire coastline consists of rocky cliffs. Along with nearby Santa Luzia and Ilhéu Branco, it was declared a protected area in 1990.

Fauna

Raso is now the only home of the critically endangered Raso lark. The island has been identified as an Important Bird Area (IBA) by BirdLife International because, as well as the larks, it supports populations of Cape Verde shearwaters (with an estimated 2500–3750 breeding pairs), red-billed tropicbirds (25–40 pairs) and Iago sparrows. It is one of only two islands where the possibly extinct Cape Verde giant skink has been recorded. The Cape Verde giant gecko (Tarentola gigas) and a skink (Mabuya stangeri) still occur.