A same-sex penguin couple have become parents after the egg they adopted successfully hatched at Valencia aquarium.
The two female penguins, Electra and Viola, at Oceanografic Aquarium in Valencia, Spain, hatched another couple’s egg.
Although the two penguins are infertile together, aquarium staff placed the egg from another penguin in their nest after they appeared to be broody.
Same-sex couples are common in more than 450 species in nature, although this is the aquarium’s first same-sex couple.
‘Electra and Viola are female and have been able to adopt, hatch and raise an egg from another couple, something that’s happened for the first time at the Oceanogràfic,’ the aquarium said in a blog post, calling them an ‘exceptional pair’.
The as yet unnamed addition is one of three chicks born so far to the colony of 25 Gentoo penguins (Pygoscelis papua) at Oceanogràfic this breeding season.
The three couples that have raised chicks so far have been two heterosexual pairs Navi and Aquela and Bolo and Melibea, as well as Electra and Viola.
The pair of females had begun to show typical penguin behaviours prior to reproduction, such as building their own nest out of stones.
Seeing this, aquarium staff moved a fertile egg from another couple and placed in Electra and Viola’s nest, who successfully carried out the entire breeding process.
Electra and Viola aren’t the first same-sex penguin couple to raise a chick, however, as homosexuality is common in penguins.
At Berlin Zoo last year, male couple Skipper and Ping adopted an egg that had been abandoned by its mother.
The two had previously displayed their instincts as nurturers by trying to hatch stones and even fish.
In London’s Sea Life Centre, meanwhile, a chick adopted by a pair of female penguins last year is being raised as gender-neutral by its keepers.
‘While the decision may ruffle a few feathers, gender neutrality in humans has only recently become a widespread topic of conversation,’ Graham McGrath, the centre’s general manager, said at the time.
‘However, it is completely natural for penguins to develop genderless identities as they grow into mature adults.’
Penguin reproduction normally begins with the construction of the nests that consist of round pebbles, which can reach more than 7 inches on each side, the aquarium said.
Stones are a very precious commodity for these animals and can even be part of the courtship ritual normally initiated by the male.
During courtship, the male will find the smoothest pebble to present to the female as a gift and a symbol of his affection.
If the female likes the gift, she will place it in the nest and the two will continue building up a pebble mound in preparation for the eggs.
The father and the mother then take turns every day to keep the egg warm during incubation.
The eggs hatch at 38 days and the chicks usually become independent at 75 days with an approximate weight of 6 to 7 kilograms.
Emperor and king penguins are the exception to stone nest-building, which lay one single egg, rest it on their feet and keep it warm under a feathery fold of skin.