Translocations of petrel colonies is a valuable conservation tool used to conserve rare Procellariiforme seabirds and restore natural habitats. The seafood diets selected to feed petrel chicks during translocations are often heavily influenced by the practical limitations of storage, cost and availability in remote locations. The same diets are fed to various seabird species, irrespective of their different foraging strategies and diverse prey items. In New Zealand a tinned sardine in soya oil based diet has been used to feed over 14 different species of petrels during translocations, including the critically endangered Taiko Pterodroma magenta. Feeding this sardine based diet for longer periods has resulted in deaths related to nutritional disease. This raises the concern that birds may be fledging with malnutrition which could impact on their survival at sea.
This study assess the effects of feeding different artificial diets to petrel chicks by running a dietary trial during a colony translocation of 76 grey-faced petrel chicks, Pterodroma macroptera gouldi from Motuhora Island (37o52'S, 176o58'E) to Cape Sanctuary (39o40'S, 177o06'E). The chicks were fed either tinned sardines in soya oil, or a powdered Mazuri fish analog© diet supplemented with fish oil. Results of the dietary trial will be presented; comparing the effects of the diet on growth parameters, fledging rates and the disease incidence during the translocation.
To compare the nutrient content of artificial diets with wild diets, proventricular samples of freshly fed wild chicks were collected from a control colony of grey-faced petrels in West Auckland (36o54'S, 174o27'E). Blood samples from wild and translocated chicks were also taken to measure the change in erythrocyte phospholipid ratios that occurred while being transitioned from the wild diet to different oil based diets, over a 3 week period. The results of this study will improve the diet choices for future seabird translocations.