Female-female Albatross pairings
Figure is taken from Young et al 2008 (full citation at bottom of post).
I came across this paper looking for something to read in my ornithology class tomorrow. Albatross populations, along with many other oceanic bird species, are threatened by a number of compounding factors, most of which are anthropogenic - including long-line fishing, nest predation from invasive mammalian species on the small islands where breeding colonies are located, ingestion of plastics and other toxins in the ocean, etc. This is particularly troubling for Albatross species because (1) they are long-lived seabirds - which means they don’t begin to breed until their 7th year; (2) courtship (finding a mate) is a long process that takes a few years to build trust with another individual bird; and (3) they are particularly monogamous and only hatch one egg per breeding season.
Well, as it turns out, there has been male-biased mortality in some areas and so some populations have a skewed sex-ratio - 59% females in the population reviewed in this particular paper. This has created an observable change in the social behavior of the birds within this population. Approx. 30% of the pairings within this one breeding colony were unrelated female-female pairings - and they found that many of the pairings stayed together for 4+ years, one even for 19 years. And during those years, females alternated breeding while both raised the young.
And actually, female-female pairings are not uncommon in shorebirds, particularly when there is a female-biased sex ratio. It was just a recent paper and I thought it was cool to share. Because I feel as though a lot of these sorts of papers/records get pushed aside in science just because it doesn’t fit the “norm” (and I’m not talking human social norms here, although there are certainly biases formed from those as well and they definitely affect what mainstream science thinks of as important and worth teaching about).
If I ever become a professor somewhere, I’d really love to teach a class about variation in gender/sex/sexuality/etc within the animal kingdom. It would probably follow along the lines of Joan Roughgarden’s Evolution’s Rainbow.
Citation: Young, L. C., B. J. Zaun, and E. A. Vanderwerf. 2008. Successful same-sex pairing in Laysan albatross. Biology Letters 4: 323-325.
