Adelie penguin occupancy survey of the Rookery Island Group, 2015

Subcolonies were mapped by circumnavigating the perimeter on foot while carrying a Garmin GPS (Etrex30) to record the track. When mapping the perimeter of the subcolonies, generally an average buffer distance of 2.5 meters was maintained between the mapper and breeding birds.

However on Gibbney and Rookery Island one of the mappers was mapping at a distance between 3 and 5m. Buffer distances were reduced accordingly for the varying tracks to produce a combined average buffer distance of 2m in the final layer. Given this the boundary mapping for these two islands may vary in accuracy.