Dietary studies of Adélie penguins through faecal DNA analysis

The composition of penguin diet is currently monitored through the A8 CEMP Chick Diet monitoring parameter. The current Standard Method involves stomach lavage to collect the stomach contents of adult birds and sorting the samples to identify prey composition and mass. At WG-EMM-12 it was noted that Australia had stopped collecting penguin diet samples and that alternative, less invasive, procedures were under consideration. Here we discuss results from recent work using the extraction of prey DNA from penguin faecal samples as an alternative, non-invasive procedure. We describe the technique, discuss recent results and outline current thoughts on its advantages and limitations. We also outline a validation study currently underway on samples collected at Signy Island, South Orkneys, to compare the prey DNA from faecal samples and stomach lavage techniques.