Dual Mommies

Pairs of female Laysan Albatross help each other raise offspring. They are now successfully re-colonising islands

Pairs of female Laysan Albatross help each other raise offspring. They are now successfully re-colonising islands

The Laysan albatross employs a strategy called reciprocity, where unrelated females pair together and take turns raising offspring. On the island of Oahu, in Hawaii, 31 per cent of nests are female-female pairs. Female pairs raise fewer chicks than male-female pairs, but given the shortage of males, fewer chicks are better than none. Since albatross can only raise one chick each year, females stay together for multiple years for each to reproduce. This unusual strategy may explain why Laysan Albatross are successfully re-colonising islands, according to a study report in Science Daily. The study documents long-term pairing of unrelated female Laysan albatross and shows how cooperation may have arisen as a result of a skewed sex ratio in this species. Thirty-one per cent of Laysan albatross pairs on Oahu were female-female, and the overall sex ratio was 59 per cent females as a result of female-biased immigration. For most female-female pairs that raised a chick in more than one year, at least one offspring was genetically related to each female, indicating that both females had opportunities to reproduce.

albatrossreciprocitysame-sex behaviour