A sensitivity analysis of Hutton's shearwater: prioritizing conservation research and management

Hutton's shearwater Puffinus huttoni is an endangered seabird that breeds a t just two colonies, which are subject to predation from introduced mammals . Whether the remaining populations are stable is unknown. In order to help focus future research and management into key areas, we developed a popula tion model of Hutton's shearwaters. The model incorporated environmental va riation and also included uncertainty in the estimation of both the mean an d the between-year variation of parameters. The sensitivity analysis indica ted that the population growth rate of the model was most influenced by the values of mean adult survival, recruitment and the between-year variation in adult survival. In contrast, the model was relatively robust to variatio n in the mean and between-year variation of most breeding parameters. Futur e research would best be directed away from measuring breeding parameters a lone and focused on determining causes of adult and juvenile mortality such as by-catch at sea and numbers of adults preyed upon by stoats (Mustela er minea). It is important to assess both average rates of mortality and betwe en-year variation in this rate. (C) 2001 Elsevier Science Ltd. All rights r eserved.