Birds

There are about 10 thousand living varieties, more than 50 percent of which will be passerine, or "perching" birds. Birds possess wings whose development varies according in order to species; the just known groups with no wings will be the wiped out moa and elefant birds.  birds for sale near me Wings, which in turn evolved from forelimbs, gave birds the ability to fly, although additional evolution has led to the losing of flight in some birds, including ratites, penguins, and diverse native to the island island species. Typically the digestive and breathing systems of chickens are also distinctly adapted for flight. Some bird species of aquatic conditions, particularly seabirds plus some waterbirds, have further evolved for swimming.

Birds will be descendants of the primitive avialans (whose members include Archaeopteryx) which first made an appearance about 160 million years ago (mya) in China. Based on DNA evidence, modern birds (Neornithes) developed in the Midsection to Late Cretaceous, and diversified considerably around the moments of the Cretaceous? Paleogene extinction event 66 mya, which slain off the pterosaurs and non-avian dinosaurs.

Many social types pass on knowledge across generations, which is considered a type of tradition. Birds are cultural, communicating with visible signals, calls, and songs, and playing such behaviours as cooperative breeding in addition to hunting, flocking, and even mobbing of possible predators. The vast bulk of bird types are socially (but not necessarily sexually) monogamous, usually for one breeding time at a moment, sometimes for yrs, but rarely for life. Other types have breeding methods that are polygynous (one male together with many females) or, rarely, polyandrous (one female with many males). Birds produce kids by laying ova which are fertilised through sexual reproduction. They are generally laid within a nest and incubated by the parents. Many birds have the extended period of parental care following hatching