useless natural history trivia V

[cab67]

1. If one were to list the ten fastest birds in horizontal flight, half would be waterfowl. People don’t appreciate just how fast they are on the wing.


2. Not one bird in the world has blue pigment in its feathers. Blue jays, bluebirds, bluetits, black-throated blue warblers, blue-headed vireos? Cerulean warblers, indigo buntings, azure-crowned hummingbirds, sapphire-spangled emeralds? No blue in the feathers. No azure, cerulean, indigo, or any other shade of blue.

Their feathers look blue because of the way light bounces off them.

This is also true for the skin of a bird if no feathers are present. The legs of blue-footed boobies and the heads and necks of cassowaries come to mind.

(Most of the red and yellow in bird feathers is from dietary sources and not made by the bird itself.)


3. There were horned rodents in central North America between around 17 million and 6 million years ago. They would have looked like horned prairie dogs or marmots, though they’re only distantly related to either of these. (Neither prairie dogs or marmots, of course, are horned.)


4. Charles Darwin once predicted the existence of a bizarre moth before the moth was discovered. He was sent some flowers from southern Africa with really, really long nectaries. He suggested that a moth with a really, really long “tongue” (proboscis) would be its primary pollinator. (Closely related flowers in that region are pollinated by moths.).

This turned out to be true – Morgan’s sphinx moth, Xanthopan morganii, had been named in 1856 (about 8 years before Darwin made his prediction), but it’s excessively long proboscis wasn’t observed until the early 20th century. At fullest extent, the proboscis is three times longer than the body.


5. You know how sharks are cartilaginous fish with no bone? Actually – not entirely true. Most extinct sharks had bony spines supporting the dorsal fins. Some modern sharks still have these. In fact, the stinger on a stingray is a modified fin spine, and it’s still bony.

(One could make a case that teeth and skin denticles - the "scales" on a shark that look a lot like teeny tiny teeth - are also a form of bone. The skin denticles are formed primarily of dentine with an enamel or enameloid coating surrounding a pulp cavity.)

The last common ancestor of sharks and modern bony fishes was way bonier than a shark. That sharks have so little bone isn't because they're primitive; it's because they lost much of the bone found in their ancestors.