When two female royal albatrosses at a New Zealand breeding colony embarked on a lesbian relationship, there were some raised eyebrows. But when the pair successfully incubated a chick, wildlife experts were delighted – and surprised.
The father – one of scores of males at the Taiaroa Head Royal Albatross Centre on the South Island's wind-swept Otago Peninsula – appears to have disappeared. He will play no role in the upbringing of his week-old chick and, just like an increasing number of children, this bird will grow up with two mothers.
"It's quite unusual in the albatross population here at Taiaroa Head to have two females mating together," Lyndon Perriman, the colony's head ranger, told Television New Zealand. "Even more unusual than that is that the egg is actually fertile this season."
While homosexuality is well documented in the animal kingdom, including among seabirds, Taiaroa Head – the only mainland albatross breeding colony in the world – has recorded only two previous instances of females setting up a nest together in the past 70 years. Neither resulted in a happy ending.
The latest pair had tried nesting with a male albatross during two previous breeding seasons, but the threesome did not work out. This time, the two females took turns sitting on the egg.
Sam Inder, the manager of the centre, said: "It's an unusual situation because we've had a triangle with one male and two females for the past couple of years, and obviously that hasn't been terribly conducive to getting on with a breeding programme. This year the male left the trio, but obviously not before he had mated with one of the females."
The male has not been seen since, and Mr Inder told the Australian Broadcasting Corporation: "My personal view would be having to live with two women might be just a bit demanding."
Initially, rangers at the centre were not sure whether the female pair would stay together, so they tried them out with a dummy egg. When they proved to be good parents, the original egg was returned to the nest. Now the ladies are taking turns to guard the chick and fly out to sea to fetch food.
There are about 140 royal albatrosses on the colony with wingspans of nearly 10 feet. This season 17 chicks have hatched from 17 fertile eggs, a rare 100 per cent success rate.
Following widespread coverage of the newborn albatross with two mothers, including in the gay press, Tourism Dunedin is now canvassing suggestions for a name for the chick.
It is not the only same-sex pairing within the animal world on the Otago Peninsula, just south of Dunedin. Currently, two male yellow-eyed penguins – an endangered species like the royal albatross– are incubating an egg.