Penguins have a bank of mum and dad: Researchers find grown up birds still beg their parents for food (and get it if fish are plentiful)

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Just like humans, Galapagos penguins who have ‘left the nest’ still turn to their parents for support.

Researchers studying the species in the Galapagos Islands discovered that fully grown offspring beg for food when adults return from feeding – and sometimes, the parents will oblige.

This behaviour is extremely rare among penguins, with just one other species known to do the same, and experts say it may have emerged as a result of the fluctuating food patterns in the islands.

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Researchers studying the species in the Galapagos Islands discovered that fully grown offspring beg for food when adults return from feeding – and sometimes, the parents will oblige. In the photo above, an adult can be seen feeding a fledgling 

Researchers led by a biologist at the University of Washington suspect that parents are more likely to give in to their grown offspring’s begging when food is bountiful.

The behaviour is rare, but over roughly a decade of field observations, the team observed it on numerous occasions.

‘Through field seasons over the years when we were observing penguin behaviour in the Galapagos Islands, we saw these isolated instances of adults feeding individuals who had obviously fledged and left the nest,’ said Dee Boersma, a UW biology professor.

‘And now we’ve collected enough field observations to say that post-fledging parental care is a normal – though probably rare – part of Galapagos penguin behaviour.’

The researchers observed five instances of post-fledging parental care in the wild from February 2006 to July 2015.

These adult offspring who have just left the nest are known as fledglings.

At this point, they’re about 60 days old, and have distinctly light coloured feet and cheeks, along with a relatively new coat of adult feathers.

The team found that fledglings would beg on the beach for food using vocalizations as the adults came out of the water.

While some adults would peck the fledgling away or ignore it, some were found to regurgitate food to the begging bird.

According to the researchers, those adults who complied and fed a fledgling were likely its parents, as penguin parents and offspring use a number of cues to recognize each other.

Galapagos penguins have several characteristics that set them apart from other species due to the unusual nature of the archipelago.

The volcanic islands sit on the equator, meaning its inhabitants are subjected to a number of extreme conditions, including high heat and dry land surrounded by cool ocean waters.

And, the oceanic food supply fluctuates depending on climate patterns in the wider Pacific basin.

As a result, the penguins adjust their behaviour.

Unlike other species, they’re known to prioritize molting, and do so twice a year, and before breeding.

Parental care may be influenced by these food fluctuations as well, the researchers say.

‘When climate patterns are ideal, ocean currents bring plenty of fish to the Galapagos for the penguins,’ said Boersma.

‘But when you get a strong El Nino, the adults struggle to feed themselves and meet the energy demands of their own bodies.

‘Galapagos penguins have adapted themselves not to the seasons, but to the whims of the bounty of the ocean.’

According to Boersma, parents may continue to feed their fledglings for weeks, giving their offspring time to learn to hunt effectively.

These adult offspring who have just left the nest are known as fledglings (pictured). At this point, they’re about 60 days old, and have distinctly light coloured feet and cheeks, along with a relatively new coat of adult feathers

Many other seabirds are known to do this, but in penguins, only Galapagos and Gentoo parents have been found to.

These species also stick close to their nesting site after the chick fledges, allowing them to continue feeding their offspring.

Other penguin parents molt soon after their young fledges, and often migrate from the nesting area.

Boersma says the Galapagos species may have evolved the unique behaviour to increase reproductive successes, and make the most of food availability.

‘In February 2017 when we were in the Galapagos, fully 40 percent of the penguins we counted were juveniles who fledged within the last few months,’ said Boersma.

‘That would indicate that food is plentiful and this was a good time to breed. But in the Galapagos, especially with climate change, the good times can vanish in an instant.’