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cab67

(3,787 posts)
Sat Apr 11, 2026, 01:04 PM 14 hrs ago

useless natural history trivia V

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.
16 replies = new reply since forum marked as read
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Hugin

(37,872 posts)
2. An example is flamingos are pink because of their diet.
Sat Apr 11, 2026, 01:09 PM
14 hrs ago

Without the diet they would be white like a swan

Jerry2144

(3,284 posts)
5. THat's a Jackalope if I've ever seen one
Sat Apr 11, 2026, 03:14 PM
12 hrs ago

They're rampant around here. People have been seeing them (ever since cannabis legalization)

cab67

(3,787 posts)
11. another fun fact -
Sat Apr 11, 2026, 04:44 PM
11 hrs ago

At some of the locations preserving these rodents (mylogaulids), there were also rhinos with paired horns, side-by-side rather than front-back.

Martin68

(27,821 posts)
8. As the OP mentioned, blue jay feathers have no blue pigment. They are blue because of the way they diffract light.
Sat Apr 11, 2026, 03:41 PM
12 hrs ago

cab67

(3,787 posts)
12. The light hits the feather the same way whether it's attached to the bird or not.
Sat Apr 11, 2026, 04:44 PM
11 hrs ago

Martin68

(27,821 posts)
7. When I dissected a shark in comparative Anatomy class I was able to carve away the skull from around the
Sat Apr 11, 2026, 03:40 PM
12 hrs ago

auditory spiral cochlea using a scalpel because it is made of cartilage. Very cool!

cab67

(3,787 posts)
10. Chances are...
Sat Apr 11, 2026, 04:42 PM
11 hrs ago

...the species you dissected was Squalus acanthias. They actually have bony dorsal fin spines.

They don't have internal bone, which is why you could whittle the braincase with a scalpel. BUT - unlike most extinct shark groups, the living shark radiations (Neoselachii) have calcified cartilage in their vertebral column. The vertebral centra aren't bony, but they develop calcium carbonate deposits. (Bone is calcium phosphate.). This gives them more rigidity.

cab67

(3,787 posts)
16. yes, but...
Sat Apr 11, 2026, 06:35 PM
9 hrs ago

...in this case, the light isn't bouncing off a structure with blue pigment. It's bouncing off a structure without it.

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