Posted on 20/04/2015 by Phillip Island Nature Parks
Phillip Island’s penguins don’t need to travel as far for food in winter as was originally thought, according to new research published in Royal Society Open Science.
Researchers at Phillip Island Nature Parks and Monash University have solved a long-standing puzzle. It was known that the penguins’ winter diet included fish which are normally found off-shore in open waters, but the penguins from Phillip Island frequented Port Phillip Bay during winter, and the penguins from St Kilda did not leave the bay, so how could this be?
Analysis of the stomach contents and stable isotope levels of a group of penguins at the St Kilda breakwater showed that during breeding season, the penguins fed on migrating communities of fish that entered the bay to spawn, while during winter, the penguins fed on juvenile anchovies that used the bay as a nursery, which was reflected in the low Carbon signature in their blood. This allowed the penguins to stay close to their breeding colony in the search for food.
This is truly a case of the prey taking itself to the predator, rather than the predator having to go far and wide in search of food. This research has also highlighted that penguins are able to switch between types of prey in response to fluctuations in availability. It is therefore important to identify and protect the environmental features that attract and sustain spawning and juvenile fish communities, rather than attempting to ensure that a specific prey stock is available.
Read the complete Research Paper here