BIRDS ARE FLYING REPTILES??

They tell us that warm-blooded birds evolved from cold-blooded reptiles. Well let's take a closer look at some remarkable avian features...

·        Flight feathers are stronger than steel, by weight, and grow from muscle-controlled follicles below the skin (whereas scales are skin cell extensions)

·        Many bones in a bird's skeleton are porous and hollow to reduce take-off weight

·        To facilitate rapid waste removal, birds have a basic digestive system that incorporates a crop, proventriculus and gizzard. (Park your car under a pigeon roost for a liquid demonstration.)

·        Birds have no bladder for storing urine, and no sweat glands

·        A bird's heart rate can reach 20 beats per second and it’s wings can flap at up to 80 times per second! (the hummingbird)

·        Birds sing with their unique double-sided vocal organ called a syrinx

·        Beaks are made of light weight horn - not bone

And here's the feature that is hard to find information on in textbooks (why is that?)...

·        Birds have a totally unique one-way respiratory system that uses air sacs together with a lung.  Have you ever seen a bird 'out of puff' after an aerobatic display or a marathon flight?

Wouldn't you say this animal has been purpose-built for action: fly, swim, walk, or run....rather than hibernation?

The moral of this story? 

Don't stand under a pelican.

Photo credit:
Tony Sullivan