The sooty shearwater colony at Mt Oneone (also known as the Doughboy) at the mouth of the Wanganui River is one of few mainland sooty shearwater colonies remaining in Westland (Hamilton et al. 1997). The Wanganui River Walkway provides access to a viewing platform on top of Mt Oneone (65 m) and the shearwater colony is beneath this platform. In this study we set out to determine the status of, and breeding success at, the Mt Oneone colony.