Cape Verde – the deserted island, Santa Luzia

[Posted on behalf of Paul Donald, a man who truly loves larks]

Landing on the lovely beaches Santa Luzia is slightly easier than jumping from a moving boat onto the low cliffs of Raso, but we were still drenched when we waded ashore. Santa Luzia is a giant compared with Raso, covering 35 square kilometres, but it has not been permanently inhabited since the 1970s. All that remains of its former inhabitants are their ruined houses and a few stone walls. Actually, that is not quite all that remains, for when the people left, the animals they brought with them stayed, and Santa Luzia now has the problem that so many islands around the world face, that of introduced mammals.

Because cats and mice are firmly established, there are very few birds on the island. The most conspicuous absence is at night – in all their time on the island, José and Tommy Melo of the local conservation group Biosfera have never heard the weird nocturnal calls of breeding seabirds, many species of which should be present. Absent also are Raso larks, yet we know they were once here, and by a most unexpected means. Barn owls breed occasionally on Santa Luzia and they use the same nest sites for many years. Their pellets and droppings accumulate over long periods, allowing scientists to treat them as archaeological sites. Careful excavations have shown that the lower, older layers contain the bones of Raso larks as well as native reptiles like skinks and geckoes. Then there is a sudden change, when people arrived on the island, and more recent layers contain only the bones of mice.

So Raso Larks were here, and disappeared at around the time that people arrived. Elsewhere, piles of old seabird bones bear witness to the island’s past glories. Our aim on this trip was to assess what needs to be done to restore the island, and its historic populations of Raso larks, seabirds, reptiles and turtles. Island restoration is expensive, but our visit proved that the effort would be worthwhile. We identified an area of potential Raso lark habitat that was around the same size as the whole of Raso, and everywhere we went we could see potential breeding sites for a range of seabirds.

Unfortunately, everywhere we went, we also saw signs of cats. As so often, the need is clear, but significant resources will be needed to restore what could become one of the most important  bird islands in the north Atlantic.  After two nights on the island, we had to return to Sao Nicolau across seas that were rougher than on the outward journey. Writing this several days later, my arms and legs are still stiff with the effort of clinging on.  But seeing these two wonderful islands again was well worth the pain.

We'll bring you more updates as plans progress!