A long-term study of Short-tailed Shearwaters Puffinus tenuirostris on Fisher Island, Australia

All 100–200 Short-tailed Shearwaters Puffinus tenuirostris breeding on Fisher Island, in Bass Strait, Australia, have been individually marked and their breeding performance monitored in each year since 1947. This long study has revealed that mortality rates are greater in older shearwaters and that reproductive performance varies with age, breeding experience and mate familiarity in complex ways. A single study population proved inadequate, however, for estimating pre-breeding survival rates, recruitment rates, emigration and immigration.