Optimising translocation efforts of Mottled Petrels (Pterodroma inexpectata): growth, provisioning, meal size and the efficacy of an artificial diet for chicks

Abstract

In an effort to promote population recovery, translocations of the endemic Mottled Petrel (Pterodroma inexpectata) from remote offshore islands to the mainland are planned within New Zealand. To optimise these efforts we studied chick growth, adult provisioning and meal size for this species and report the results of a simulated translocation undertaken to assess how translocated chicks, fed an artificial diet, performed in comparison with handled and non-handled controls that were provisioned by their parents. Our results found that wing-chord length and chick mass did not differ between translocated and control chicks, with all chicks fledging at approximately the same mass and wing size ranges. There was no difference in the timing of emergence from burrows before fledging between control and translocated chicks. The probability of a chick receiving a meal each night declined as chicks approached fledging and average meal size did not change as chicks approached fledging. From these data we now have the basis with which to make recommendations to increase the success of future translocation efforts for Mottled Petrels. It is important to share any knowledge of the biology and ecology of gadfly petrels, and any successes or failures in translocation practices in order to promote the best possible chance of future conservation of these species.