Premium Only Content
Charming Birds -1-
Birds are a group of warm-blooded vertebrates constituting the class Aves, characterized by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweight skeleton. Birds live worldwide and range in size from the 5 cm (2 in) bee hummingbird to the 2.75 m (9 ft) ostrich. There are about ten thousand living species, more than half of which are passerine, or "perching" birds. Birds have wings whose development varies according to species; the only known groups without wings are the extinct moa and elephant birds. Wings, which evolved from forelimbs, gave birds the ability to fly, although further evolution has led to the loss of flight in some birds, including ratites, penguins, and diverse endemic island species. The digestive and respiratory systems of birds are also uniquely adapted for flight. Some bird species of aquatic environments, particularly seabirds and some waterbirds, have further evolved for swimming.
-
0:28
kainduk
4 years ago $0.01 earnedRunning birds
2332 -
0:14
ZHELT
4 years agoBirds are cool
51 -
0:30
TonyShmeat
4 years ago $0.03 earnedbirds eating papaya
1894 -
0:39
Louzzoo
4 years ago $0.01 earnedBirds riding birds compilation
147 -
0:40
TheDad58
4 years agoBirds In Slowmo
90 -
2:18
WMAR
4 years agoBirds preparing for migration
712 -
0:13
Abough
4 years agoLove birds enjoy
1231 -
0:39
Manchy
4 years agoFlock of birds
40 -
0:06
Toporkow
4 years ago $0.01 earnedHungry birds!
1732 -
0:29
Ohdoylerules519
4 years agoBirds chilling
53