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
Christmas shearwater and introduced black rats took eggs and chicks. In 1985, the population on Sala-y-Gómez, a nature sanctuary, was estimated at 5,000. With its wide range and considerable numbers, the Christmas shearwater is considered a species of least concern by the IUCN. Christmas shearwater The Christmas shearwater ("Puffinus nativitatis") is a medium-sized shearwater of the tropical Central Pacific. It is a poorly known species due to its remote nesting habits, and it has not been extensively studied at sea either. It is one member of a very ancient lineage of the small "Puffinus" species. Its only close living relative is the