Isles of Scilly Wildlife Trust Gugh, brown rat ("Rattus norvegicus") free, to help breeding sea birds, which lost 25% of their populations between 1983 and 2006. The rats eat eggs and kill the chicks of those birds that nest in burrows or on the ground. Rat removal began in October 2013 by a team of thirty volunteers led by Wildlife Management International Limited (WMIL) of New Zealand, and there has been no signs of rats on St Agnes and Gugh since December 2013. WMIL will return to the islands to do a final check for rats in 2016. In 2014 Manx shearwater ("Puffinus puffinus") bred
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