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birds - choose a jigsaw puzzle to solve

Birds (Aves) are a group of endothermic vertebrates, characterised 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. They rank as the world’s most numerically-successful class of tetrapods, with approximately ten thousand living species, more than half of these being passerines, sometimes known as perching birds. Birds have wings which are more or less developed depending on the 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 flightless birds, including ratites, penguins, and diverse endemic island species of birds. 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. Reverse genetic engineering and the fossil record both demonstrate that birds are modern feathered dinosaurs, having evolved from earlier feathered dinosaurs within the theropod group, which are traditionally placed within the saurischian dinosaurs. The closest living relatives of birds are the crocodilians. Primitive bird-like dinosaurs that lie outside class Aves proper, in the broader group Avialae, have been found dating back to the mid-Jurassic period, around 170 million years ago.
Gray hens. - Animals. Birds. Gray hens.
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Gray hens.

Added 4 days ago by Grażyna

49

Cranes are flying. - A flock of flying cranes.
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Cranes are flying.

Added 5 days ago by Grażyna

16

Swans. - Swans at Hyde Park in London.
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Swans.

Added week ago by Grażyna

22

Two boos. - Two storks on the nest.
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Two boos.

Added 3 weeks ago by Grażyna

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Wild birds. - Wild birds on the feeding ground.
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Wild birds.

Added 3 weeks ago by Grażyna

15

Flamingos. - Beautiful flamingos birds.
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Flamingos.

Added 2 months ago by Grażyna

69

Beautiful peacock. - Birds. A beautiful colorful peacock.
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Beautiful peacock.

Added 2 months ago by Grażyna

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Pigeons in the wild - Pigeons looking for shelter in one of the Polish jungles.
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Pigeons in the wild

Added 3 months ago by Ann

57

Flamingos. - A flock of flamingos over the water.
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Flamingos.

Added 3 months ago by Grażyna

39

Menacing birds. - A flock of dangerous birds on the tree.
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Menacing birds.

Added 4 months ago by Grażyna

36

Flamingos. - Charming in the pond flamingos
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Flamingos.

Added 4 months ago by Grażyna

6

Swans. - Two swans: white and black.
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Swans.

Added 4 months ago by Grażyna

70

nice jackdaw - Very friendly girl at the Kosciuszko square in Gdynia.
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nice jackdaw

Added year ago by Mariusz

44

Common evening - Enjoying the sunset by small friends
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Common evening

Added year ago by ewunia x

602 3

Princess anime - Beautiful anime princess, dressed in a rich dress. Orange dress with flounces and ruffles. A beautif
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Princess anime

Added year ago by Ariadna

16

bird dance - birds, dance, feet, feathers
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bird dance

Added year ago by wieslawa

169 2