Puffinus and cold waters. These tubenose birds fly with stiff wings, and use a shearing flight technique to move across wave fronts with the minimum of active flight. Some small species, such as the Manx shearwater, are cruciform in flight, with their long wings held directly out from their bodies. Many are long-distance migrants, perhaps most spectacularly the sooty and short-tailed shearwaters, which perform migrations of 14,000 km or more each year. "Puffinus" shearwaters come to islands and coastal cliffs only to breed. They are nocturnal at the colonial breeding sites, preferring moonless nights to minimise predation. They nest in burrows
Ilhéus do Rombo Cima is famous for its seabird colonies. Ilhéu Grande, which has been used by goat farmers and whalers in the past, does not currently support breeding seabirds, though large colonies must have existed formerly as the island has thick layers of guano. The island group has been identified as an Important Bird Area (IBA) by BirdLife International because it supports seabird colonies as well as peregrine falcons and Iago sparrows. Birds include the Frigate bird ("Pelagodroma marina") numbering around 1,000 in 1989, the Boyd's shearwater ("Puffinus boydi"), "Oceanodroma castro", Bulwer's petrel ("Bulweria bulwerii"), the brown booby ("Sula leucogaster") (50 pairs