Dendrocygna viduata – white-faced whistling ducks, Botswana. The photographer writes, "Here is a trio of white-faced whistling ducks. It’s not a particularly scientifically informative shot, but it’s one of my all-time favorite photos. Whistling ducks, on the other hand, are interesting from a number of perspectives. They’re the sister group of all other Anatidae, and they’re a very old genus: genetic divergence within Dendrocygna is approximately equal to that within the rest of Anatidae. And yet they all look pretty much alike, so we have a fine example of morphological stasis. That may also be the reason that white-faced whistling ducks, with fairly sedentary habits, are nevertheless found in both Africa and South America with no recognized subspecific variation. (Fulvous whistling ducks D. bicolor are worse: they’re found in North and South America, Africa, and India, still with no subspecies.)"
