The Aquarium Oceanogràfic Valencia in Spain announced this month some offspring at the gentoo penguins – this is not a special feature in itself. The number of chicks is also lower than in previous years, at just three. But for the first time two penguin females raise a chick in the aquarium.
The Oceanogràfico Valencia is home to 25 gentoo penguins(Pygoscelis papua),of which only three pairs have one chick each this year. However, the special couple, Electra and Viola, were given the egg by their keepers when they noticed that the two penguin ladies were beginning to show typical breeding behavior. According to a press release from the aquarium, the two females took poses like other breeding penguins and built their own nest of pebbles.
The keepers observed the behaviour of Electra and Viola for a while and finally decided to take a fertilized egg from another couple and have it hatched by the same-sex couple. The two females successfully adopted the egg and now take care of their first offspring.
Homosexuality in the animal kingdom is by no means uncommon and has been observed in over 450 species, both in nature and in zoos. Nevertheless, it is always something special to observe the successful raising by a same-sex couple. At the Sea Life Sydney Aquarium in Australia, two gentoo penguin males built a nest together in 2018, after which the keepers initially gave them an “exercise egg”. They turned out to be attentive fathers and were then given a real egg to hatch. Also at Sea Life London, two penguin fathers raised a chick last year.
With penguins, both partners are always involved in the breeding process: they start with the common nest-building of pebbles, which they arrange with great care. That is why pebbles are also such a valuable asset for the animals which they defend at all costs and which is why disputes between neighbours often occur. The stone nests can be quite large with a height of 20 centimetres and a diameter of 25 centimetres. Males also use the pebbles in the search for partners to impress females. It is not known whether Electra or Viola exhibited this behavior.
In the wild, gentoo penguins always lay two eggs, which are incubated by both parents. After 34 to 37 days, the chicks hatch, which remain in the nest for about 30 days before joining a “kindergarten” with other chicks. The chicks have completed their first moulting after 80 to 100 days and are off on their own from that moment on in search of food.
In nature, gentoo penguins live around the Antarctic continent and breed on the Falkland Islands, South Georgia and other sub-Antarctic islands and the Antarctic Peninsula. The IUCN estimates the population at 520,000 birds, with some populations currently declining.
Julia Hager, PolarJournal