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
Black-vented shearwater central and southern California during the country's colder months. The black-vented shearwater is thought to feed on mainly small fish. This bird nests in burrows and caves; it is a colonial nester. In the past, this bird had been threatened by feral cats and other predators on its breeding islands, but the problem seems to have been largely eliminated. There is some loss of birds from commercial gill netting, and the species is classified as near threatened by the IUCN mainly due to the uncertain impact on it by the expanding fishing industry. Black-vented shearwater The black-vented shearwater ("Puffinus opisthomelas")