The response of a colony of sooty shearwater ( <i>Puffinus griseus</i> ) and flesh‐footed shearwater (P. <i>carneipes</i> ) to the cessation of harvesting and the eradication of Norway rats ( <i>Rattus norvegicus</i> )

Abstract

Abstract The young of the sooty shearwater and flesh‐footed shearwater have traditionally been harvested from Titi Island in Cook Strait, New Zealand. The apparent decline of this breeding colony prompted the cessation of harvesting in 1960 and the eradication of Norway rats during the 1970s. An increase in the colony was expected, and there have been attempts to measure this by counting the number of active burrows in fixed 10 m × 10 m plots from 1987 to 1998. No change was detected over this period. Possible reasons for this are discussed. The decline is consistent with a more widely observed decline in sooty shearwater numbers, and with the likelihood that this colony has always been on the margin of these species’ range.