|Little Penguins / Credit: Phillip Island Nature Parks|
"When little penguins finish what we call the 'guard stage' and can first leave their chicks for extended periods of time, they are quite hungry, so they go on two long trips, which allows them to replenish their own energy stocks," says Dr Andre Chiaradia, a biologist at Phillip Island Nature Parks and co-author of the study.The scientists used tracking devices to follow the number and duration of foraging trips. Short-range trips were more common in seasons when food was plentiful, but the penguins performed the long-range feeding trips every year regardless of food availability near the shore.
"These extended journeys are well known in offshore seabirds like albatross, but normally we would expect inshore seabirds like the little penguin to take only short trips," he told Australian Geographic.
"Short foraging trips yield larger meals and allow for regular provisioning of chicks. But adults can deplete their energy reserves during these trips and ultimately risk their own survival," says co-author Claire Saraux, a PhD student from the University of Strasbourg in France.
To replenish themselves, adults have to take some longer trips when they reach a critically low body weight, she says. "The two consecutive long trips therefore enable little penguin parents to rebuild their reserves before another round of short trips."
The study will be published in the journal Ecology, but it does not appear to be online yet.