This week there’s a bonus bird, for a reason that will be apparent. Steamer Ducks are birds of the genus Tachyeres meaning “fast rower.” And they can motor right along. Here’s a trio of Flying Steamer Ducks from Tierra del Fuego on the southern tip of South America.
These are dabbling ducks, like Mallards, but this is an especially heavy-bodied duck, weighing in at almost seven pounds. And it’s a bad-ass bird, highly territorial and attacking other birds, even herons. A battle between two drakes is a long, bloody affair.
But it’s the smallest member of the Steamer Duck genus. The Falkland Steamer Duck, endemic to the Falkland Islands, weighs as much as 22 pounds, as Charles Darwin noted when he passed through in 1833.
In these islands a great loggerheaded duck or goose (Anas brachyptera), which sometimes weighs twenty-two pounds, is very abundant. These birds were in former days called, from their extraordinary manner of paddling and splashing upon the water, race-horses; but now they are named, much more appropriately, steamers. Their wings are too small and weak to allow of flight, but by their aid, partly swimming and partly flapping the surface of the water, they move very quickly. The manner is something like that by which the common house-duck escapes when pursued by a dog; but I am nearly sure that the steamer moves its wings alternately, instead of both together, as in other birds. These clumsy, loggerheaded ducks make such a noise and splashing, that the effect is exceedingly curious.
Wait, you say, how can a duck that weighs 22 pounds fly?
It can’t. The wings are ridiculously small. It’s flightless.
In the absence of predators, the evolutionary advantages of flight are mostly lost. Island ecologies, in particular, sometimes make the anatomical costs of flight a liability, at least in evolutionary terms. The ability to swim very fast instead, with powerful leg muscles that are too heavy for a flying species, might be more useful. Flight muscles consume a lot of energy, even when you aren’t flying. Hence, the Falkland Steamer Duck.
Altogether, there are about 60 species of flightless birds surviving on the planet. Humans, rats, cats and dogs have destroyed the rest, because those extinct flightless birds hadn’t evolved in the presence of predators.
For more bird photos, please visit Frozen Feather Images.