Everyone, meet the steamer duck. The steamer duck is one bad mother. See those orange nubbins on its wings? Those are keratinized spurs, which the steamer duck has evolved to wallop the living cuss out of any creature hapless enough to cross its path. (See that red stuff on the duck's head? Yeah. That's blood.)
Photos featured by kind permission of Arthur Grosset. See more of his photography here.
Over at Absurd Creature of the Week, Matt Simon recounts a disturbing instance of duck-on-duck violence, involving a pugnacious male steamer duck, an unfortunate shoveler duck, and an onlooking female steamer:
From time to time the steamer would drag the shoveler under, then resurface and continue beating the tar out of it as the female watched. At one point he shuffled over to her, but after 30 seconds returned to his victim and punched the poor critter 15 to 20 more times. "He then released the limp body of the shoveler," wrote Nuechterlein, "pecked at it, and released it again." At last he returned to the female for good, calling to her while she stretched, and the two flew off together. The shoveler eventually regained consciousness, and though seriously crippled, struggled to shore. It died 15 minutes later.
This is the avian version of Bloodsport, only without all of the terrible yet somehow endearing acting. The four species of steamer duck (so named for their penchant for flapping and running along the surface, kicking up water like steamboats) in South America are famous—at least in ornithological circles—for their brutality, getting all up in the grills of not just other steamers, but also other species in scrums lasting as long as 20 minutes.
Why the ducks are so aggressive is unclear, but one hypothesis is that steamers have evolved to be violent not only to chase off threats and competition, but to make an example of them:
Says Nuechterlein in the paper describing the fight between the steamer and the shoveler: "Possibly observational learning is important, and holding a 'public beating' enhances the effectiveness of territorial displays." And that, my friends, may be the only time "public beating" has ever appeared in a scientific paper.