ability to fly. Some use ground travel. Some use claws, others use only their
beaks. Birds come in many varieties of colors and sizes.
Birds are warm-blooded, egg-laying creatures from the aves class. Along
with the obvious feathers and wings, birds have other adaptations for flying
shores of Antarctica to the hottest parts of the tropics and from mountains,
deserts, plains, and facts to open oceans and deeply urbanized areas.
The sizes of birds range from the tiny bee hummingbird, which has a
total length of two and a half inches, to the albatross, which has a wing span
pounds. Other extinct birds have been measured to stand over ten feet high.
from archaeopteryx. The fossils that have been discovered from archaeopteryx
include six partial skeletons and one single feather. Archaeopteryx , unlike
modern birds, had teeth, a reptile like tail, and three claws on each wings.
Scientists think it could fly, but only weakly.
Approximately 85 species and 50 sub species have become extinct in the
last 300 years. Over half of them occurred in the 1800?s. Another thirty percent
occurred in the 1900?s. Over ninety percent of these extinction?s were island
forms, which are particularly vulnerable to human interference. Destruction of
predacious animals, and disease plays it?s part too.
themselves through perspiring. Air sacs throughout the body are connected to the
average body temperature of birds is about 106? F.
with their beaks or swallow it whole. On a bird?s esophagus their is a bag-like
stomach for it. They can also store food their for their young. In most birds,
the stomach is two parts. the first part is where digestive juices are added.
The second part, called the gizzard, has thick , muscular walls for grinding up
food. This replaces chewing. A lot of birds help the grinding process by
swallowing coarse materials like gravel. The nutritious matter is absorbed in
the small intestine. Then waste matter moves on to the large intestine. All
waste from birds release from the bird?s vent in the rear of the body.
heart of a large bird, like an ostrich, beats approximately the same rate of a
heart beat of more than 1000 times a minute! Arteries in birds carry blood from
the heart to organs in the body. Veins return blood to the bird?s heart.
cerebellum is relatively larger than a cerebellum on a mammal. The cerebellum is
Male birds have testes and the female birds have ovaries, just like in
other vertebrates. Most birds mate by pressing their vents together. Sperm cells
union produces a fertilized egg, or a zygote. When the egg is laid, the zygote
develops into an embryo as the egg is incubated.