Status: Alien Invasiveness: Invasive Occurrence: Eradicated Source: Island Conservation and Ecology Group, 2004
Arrival Date: Introduction:
Species Notes for this Location: Rattus norvegicus arrived on Ailsa Craig after ships were wrecked on the island's rocks, or perhaps on boats which supplied coal to the lighthouse built there in the 1880s (Williams, 2003).
Management Notes for this Location: R. norvegicus were eradicated from Ailsa Craig (104 ha) in 1991, after a warfarin poisoning programme led by the Ailsa Craig Working Group (J. Hughes pers. comm, Zonfrillo 2002, B. Zonfrillo, pers. comm.). Monitoring with chew sticks has proven that the island remains rat-free. Seabird breeding success has increased since the eradication, and rare plants, other mammal species and reptiles are reportedly flourishing since the removal of the rats (Williams, 2003).
Impacts: Threat to endangered species: Rattus norvegicus effectively wiped out the puffin population of Ailsa Craig, by preying on eggs and chicks (see Fratercula arctica in IUCN Red List of Threatened Species. They have bred successfully on the island since the eradication of the rats (Williams, 2003).