Interesting Bird's Facts

Everyone recognizes birds. They have feathers, wings, two legs, and a bill. Less uniquely, they have a backbone, are warm-blooded, and lay eggs. Some very Interesting Facts about Birds are:

1. The oldest bird was known as an Archaeopteryx and lived about 150 million years ago. It was the size of a raven, was covered with feathers, and had wings.
2. The most yolks ever found in a single chicken's egg is nine.
3. An ostrich egg needs to be boiled for 2 hours to get a hard-boiled egg.
4. The Royal Albatross' eggs take 79 days to hatch.
5. The egg of the hummingbird is the world's smallest bird's egg.
6. The egg of the ostrich is the world's largest bird's egg.
7. From the list of extinct elephant bird of Madagascar laid an egg that weighed 27 pounds.
8. Precolonial birds like chickens, ostriches, ducks, and seagulls hatch ready to move around. They come from eggs with bigger yolks than altricial birds like owls, woodpeckers, and most small songbirds that need a lot of care from parents in order to survive.
9. Air sacs may make up 1/5 of the body volume of a bird.
10. A bird's normal body temperature is usually 7-8 degrees hotter than a human's. 
11. Up to three-quarters of the air a bird breathes is used just for cooling down since they are unable to sweat.
12. A bird's heart beats 400 times per minute while resting and up to 1000 beats per minute while flying.
13. The world's only wingless bird is the kiwi of New Zealand.
14. Migrating ducks and geese often fly in V-shape formations. 
15. Each bird flies in the upwash of its neighbor's beating wings and this extra bit of supporting wind increases lift, thereby saving energy.
16. Falcons can swoop at over 200 mph.
17. Penguins, ostriches, and dodo birds are all birds that do not fly.
18. Hummingbirds eat about every ten minutes, slurping down twice their body weight in nectar every day.
19. The homing pigeon, Cher Ami, lost an eye and a leg while carrying a message in World-War-I. Cher Ami won the Distinguished Service Cross. Its leg was replaced with a wooden leg.
20. The only known poisonous bird in the world is the hooded pitohui of Papua, New Guinea. The poison is found in its skin and feathers.
21. The American turkey vulture helps human engineers detect cracked or broken underground fuel pipes. The leaking fuel smells like vulture food (they eat carrion), and the clustered birds show repair people where the lines need fixing.