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bird

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.
white owl - our beautiful world of nature
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white owl

Added year ago by reniulek

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lovely animals - yellow, small ducklings
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lovely animals

Added year ago by Basiunia

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dodo puzzle - dodo jigsaw puzzle dodo
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dodo puzzle

Added year ago by tre

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xd is pepe - xdxdxdxdxdxdxdxdxdxdxdxdxdxdxdxdxdxdx
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xd is pepe

Added year ago by pepe

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beautiful spring - the picture shows spring
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beautiful spring

Added year ago by Mala

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Yellow Titmouse - colorful jigsaw puzzle
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Yellow Titmouse

Added year ago by andi

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Colorful parrot - colorful parrot puzzle
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Colorful parrot

Added year ago by andi

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Peacock eyes - colorful jigsaw puzzle
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Peacock eyes

Added year ago by andi

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extremely - donald duck on roller skates
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extremely

Added year ago by stachna

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extremely - the mica mouse rests
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extremely

Added year ago by stachna

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lovely animals - cat talk with a dog
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lovely animals

Added year ago by Basiunia

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Toucan - lorem ipsum dolor sit amet
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Toucan

Added year ago by Ayla

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Ara parrot - Lorem ipsum dolor sit amet
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Ara parrot

Added year ago by Ayla

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Peacock Tail - Peacock tail okigh kiug jhvg
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Peacock Tail

Added year ago by Ayla

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lovely animals - conference or meeting
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lovely animals

Added year ago by Basiunia

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lovely animals - it's not like Mom's
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lovely animals

Added year ago by Basiunia

28 1

lovely animals - This is called friendship
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lovely animals

Added year ago by Basiunia

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Blue parakeets - Blue parakeets
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Blue parakeets

Added year ago by Ayla

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Budgerigars parrots - Budgerigars parrots
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Budgerigars parrots

Added year ago by Ayla

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Rainbow parakeets - Rainbow parakeets
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Rainbow parakeets

Added year ago by Ayla

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Colorful parrots 03 - Colorful parrots 03
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Colorful parrots 03

Added year ago by Ayla

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Colorful parrots 01 - Colorful parrots 01
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Colorful parrots 01

Added year ago by Ayla

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little boy - I'm running away and you're gonna bury me
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little boy

Added year ago by Basiunia

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lovely animals - I'm running away and you're gonna bury me
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lovely animals

Added year ago by Basiunia

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koliberek - Hummingbird is a beautiful flower
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koliberek

Added year ago by emi

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duck - PARK IN CIECHOCINKA
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duck

Added year ago by LIDIA

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Norway - Northern Norway
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Norway

Added year ago by LIDIA

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Valentine's Day - colorful jigsaw puzzle. Special day.
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Valentine's Day

Added year ago by andi

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Swim or rise - Swim or rise up?
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Swim or rise

Added year ago by elamela

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spring - spring swan
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spring

Added year ago by iga

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Animals - Misiek koala on the tree
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Animals

Added year ago by Grażyna

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Colorful parrot - colorful puzzle-puzzle
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Colorful parrot

Added year ago by andi

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Colorful parrot - colorful jigsaw puzzle
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Colorful parrot

Added year ago by andi

156 1

Spring in flowers - The spring came ... the parakeet budgerigars
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Spring in flowers

Added year ago by elamela

254 1