The UK holds 93% of the world’s breeding populations of Manx Shearwater Puffinus puffinus. Lundy Island’s populations of Manx Shearwater and Puffin Fratercula arctica, another burrow-nesting seabird, are currently much lower than those reported over 100 years ago. A major factor responsible for these declines was believed to be predation by rats. In 2002 a programme to eradicate rats to benefit these seabirds was started. Both the Black and Brown Rats Rattus rattus and R. norvegicus occurred on the island. The former is rare in the UK but both are globally widespread and abundant, and both are predators of seabirds. The two-year eradication programme was completed in March 2004, since which there has been no evidence of rats. Monitoring will now focus on the populations and productivity of the target seabirds although an increase in the breeding populations is not expected in the short term.