A large, world-famous penguin is going through some changes. Pesto, the fluffy king penguin and social media sensation from Australia’s Sea Life Melbourne Aquarium, is beginning the natural molting process. It’s completely normal, but the fluffy bird looks a little different than when it first went viral this summer. Here’s what you need to know.
Pesto begins to molt and lose its infamous fluffy feathers. CREDIT: Sea Life Melbourne Aquarium/Olivia Hill. Alex Frank
Who is Pesto?
The juvenile king penguin was born at the aquarium in January 2024. His arrival was quite exciting for the aquarium, as no other king penguins dehydrated chicks last year. Pesto is also the only king penguin to hatch this year.
Pesto weighed less than half a pound when he was born, but has gained fame on social media for his enormous size and fluffy feathers.
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Why is Pesto so big anyway?
According to Sea Life Melbourne Aquarium Education Manager Olivia Hill, Pesto’s size is a combination of nature and nurture.
“A combination of his parents’ genetics (his biological father Blake is one of Sea Life Melbourne’s largest birds) and the excellent care of his foster parents, Tango and Hudson,” says Hill. Popular science.
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Pesto quickly started to increase in size. It has already weighed 50 pounds as a young animal, while adult king penguins typically weigh 31 and 37 pounds. Pesto is the largest chick this aquarium has ever had. However, it won’t necessarily always be this big.
“He is now losing weight because his parents are no longer feeding him (as is usual at this stage as they are moulting) and will soon be as heavy as any other adult,” says Hill.
VIDEO CREDIT: Sea Life Melbourne Aquarium/Olivia Hill.
VIDEO CREDIT: Sea Life Melbourne Aquarium/Olivia Hill.
What happens to pesto in this new phase?
Pesto is growing its adult plumage. These new black, white and yellow feathers push out his old fluffy juvenile feathers in a process called molting. It usually occurs once a year in all penguin species and usually lasts two to three weeks.
“During this process, molting feathers will fall out over time, but we see the birds preening their feathers with their beaks to remove the old ones and scratching them with their toenails, creating some unique and often funny ‘hairstyles’ in the process leads,” says Heuvel. “Pesto currently looks like he’s wearing a brown feather boa over a white tuxedo shirt.”
If he loses his feathers, he will look more like other king penguins. CREDIT: Sea Life Melbourne Aquarium/Olivia Hill. Alex Frank
What does Pesto look like after molting?
Eventually he will resemble other adult king penguins. Adult king penguins typically have an orange beak plate on the sides of their beak. The juveniles have a dark brown or black bill plate. However, there is usually very little difference in their plumage, making them difficult to tell apart in the wild.
[Related: African penguins may tell each other apart by the spots in their plumage.]
“We will be able to distinguish Pesto by this dark bill plate over the next year, until he molts for the first time as an adult (November 2025). Then he will shed his black beak plate and grow an orange beak plate, which means he is mature,” says Hill. “The only way to distinguish it from all other birds is by its wing band (241 – Brown Orange Black).”
How can I see Pesto?
He can currently be seen in the aquarium, but is also active on social media.
