Jan. 2, 2008 -- Humans parade to mark special occasions, and now it's been determined that fairy penguins, also known as little penguins, parade during "good years," meaning years when food is plentiful, breeding rates are up and sea temperatures are stable.
A penguin parade consists of 5 to 10 individuals that walk together, nearly in sync, while arriving or leaving a colony.
Such parading groups strategically form on the beaches where the penguins rest and nest after foraging in the sea, according to a paper that was recently published in the journal Animal Behavior. The study is the first to demonstrate that penguins can seek to form groups with the same individuals when they come and go.
"To synchronize their arrival and departures has a cost to the individual, so they would only (parade) if there were benefits," co-author Andre Chiaradia told Discovery News.
Chiaradia, a penguin ecologist at Phillip Island Nature Park in Australia, explained that the benefits of penguin parades might include preventing predation and improving foraging success. If food supplies are limited, however, parading becomes less attractive. It would be like 10 people diving after one hamburger.
The researchers studied the diminutive black and white flightless birds at the Aussie park's Summerland Peninsula. Standing only around 16 inches tall, the little penguins are the smallest of the world's 17 known penguin species.
The scientists tagged multiple individuals with transponders so they could monitor movements without disturbing the birds' normal behavior. The study was conducted over four breeding seasons from 2001 to 2004.
During the successful breeding years of 2002 and 2003, the colony was a veritable penguin parade fest, with numerous groups forming in the morning and evening hours.
The scientists noticed that the majority of parading groups consisted of adults that nested close together and that were in similar physical shape.
"Middle-aged penguins, 5 to 11 years old, tended to have sync parades," Chiaradia explained. "We know from previous studies that these penguins are at the peak of their breeding performance, meaning they are more experienced."
He suggested it is even comparable to adult humans of a similar age, income, fitness level and so on who choose to hang out together.
Brenda Melton is a bird keeper at the San Francisco Zoo who cares for the zoo's Magellanic penguin colony, which consists of 55 individuals.
She has not observed smaller parading groups but instead, the Magellanic penguins appear to all belong to one synced community.
"The whole group often swims together and then comes back in together," Melton said. "They will even make their territory calls together."
She suspects such group behavior for Magellanic penguins functions as it does for the little penguins, in offering protection from predators and in improving feeding strategies.
In future, Chiaradia and his team hope to find out whether or not the synchronized movements on land carry over to swimming and hunting for food in the water.
He said, "We aim to deploy diving loggers on penguins with high association levels and check if they are actually diving together."
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