What makes a bird a bird?
The first thing most people notice about birds is that they can fly, but that is not what makes them unique. Bats, bugs, and butterflies also take to the air, and they aren’t birds. What makes birds different from every other kind of animal on earth are feathers. Feathers make it possible for birds to live a large part o their lives in the air. Feathers weigh very little, are strong (to survive long flights), and provide terrific insulation (which is why people living in the coldest parts of the world prefer jackets stuffed with goose down). Most birds also have hollow bones. If bird bones were solid, like human bones, birds would be too heavy, which would make flight very difficult.
Birds, from the class Aves) are bipedal, warm-blooded, vertebrate animals that lay eggs. There are around 10,000 living species, making them the most numerous tetrapod vertebrates. They live in ecosystems across the globe, from the Arctic to the Antarctic. Birds range in size from the 2 inch Bee Hummingbird to the 2.7 m Ostrich. The fossil record indicates that birds evolved from theropod dinosaurs during the Jurassic period, around 150–200 Million years ago and the earliest known bird is the Late Jurassic Archaeopteryx around 150 million years ago! Modern birds are characterised by feathers, a beak with no teeth, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a lightweight but strong skeleton. All birds have forelimbs modified as wings and most can fly, with some exceptions including ratites, penguins, and a number of diverse endemic island species. Birds also have unique digestive and respiratory systems that are highly adapted for flight.
They all have feathers and they all have wings. The feathers and wings of some birds have changed or are no longer used for flight, e.g emus or penguins, but they all have them. There are various other anatomical things which are specific to birds, such as the fact that they all have a beak or bill of some kind, most have no bladder and hollow bones. Their lungs are very different to other animals, and they have no teeth. Birds are very unique and their closest relatives are the reptiles, since they actually evolved from dinosaurs. The first proper bird is thought to be the archeopteryx. Reptiles usually lay eggs, which is where birds got it from.
Thats simple man, look a bird is a bird because it has wings and feathers. So yes…a chicken is a bird if any1’s wondering. An animal can have wings but if it does not have feathers it cannot/it should not be classed as a bird. Research is you want, their is not an animal that has wings and feathers that is not classed as a bird.
