A couple of ace birders recently had a “Ruff” time in Chatham waters. By which I, of course, mean that they found a Ruff, an exceedingly rare old-world sandpiper – the waters were actually quite calm. Painfully obscure bird puns aside, this was indeed an excellent find, representing only the 5th ever spring record for the Cape and islands. The natural history of the Ruff is the stuff of old spy novels, full of far-flung old world locales, sex, deception, and even murder. Oh, and also cross-dressing – we’ll get to that in a minute.
These birds mostly winter in the wetlands of Africa and the Near East, but return each summer to breed in Arctic Russia and Scandinavia. Here they were traditionally trapped for food by folks known locally as “wilsterflappers”, though the practice was outlawed in the 1970s. The wilsterflapper skill set is still used by old practitioners with names like actual person Joop Jukema to help researchers study the ecology of Ruffs, who have one of the weirdest mating systems in the animal kingdom.
Female Ruffs are so unlike the gaudy males that they even have a different name: the “Reeve." Not bad looking with bright orange legs and subtly beautiful brown plumage patterned with tiny heart-shaped markings, the Reeves are nevertheless totally outshined by the Liberace-esque males, who in breeding season sport huge, feathery Ruffs of either black, red, or white. Thus adorned, the males gather en masse, fight each other, and prance about for females, a mating system known as a “lek”.
Lek mating systems are uncommon but not unheard of in the bird world, but here’s where it starts getting weird – in addition to the dominant, territorial males that battle it out for females as in traditional leks, Ruffs have a second kind of male. Smaller, non-territorial, white plumaged satellite males gain access to leks, and hence females, by acting submissive to the dominant males. That’s not unheard of in lek systems, but Dutch researchers discovered yet a third type of male back in 2006. It turns out that one out of every hundred male Ruffs permanently sports a female plumage, and skulks around in the leks posing as a female. These cross dressers are called faeders, for the old English for father, and sneak in to mate with receptive females when they get the chance, decoy males away from the females, and, even weirder, have testes more than twice the size of normal males.
Hey, to each their own, and I use the term weird here only in avian mating system terms. These guys are true outliers, since the presence of permanent, female-mimicking males had never been documented in another species.
I recognize that the Ruff is an obscure bird that very, very few of you will ever see or even care about, but this species’ story was too juicy to ignore. And besides, who doesn’t love learning fun new Scandinavian words. Now if you’ll excuse me, I’m going to add “wilsterflapper” to the list of skills in my LinkedIn profile and see if I get any hits.