Avian Adaptation:
The evolution for the class of birds was said to have begun in the Jurassic period, some 200 million years ago, where they derived from small theropod carnivorous dinosaurs. Birds have undergone a complete modification from their reptilian heritage, anatomically the most significant adaptation has become their structure which permits their ability for flight.
The earliest known bird is the Archaeopteryx which survived 150 million years ago. Birds evolved from the reptile species which today can be observed through many birds feet structure. Birds feet and legs are now used for walking, perching on limbs, and even tearing flesh from prey.
Birds beaks have also adapted to break hard seeds or rip flesh from prey.
Birds are an endothermic (regulate own body temperature) species and must consume a high quantity of food to maintain their body temperature. However, the respiratory system of birds is more efficient than of mammals although they both have a 4 chamber heart in common.
Birds are the only class of vertebrates to have feathers. The bone structure of birds is unique in that they are honey combed, very light weight, yet structurally sound to withstand the stresses of flight. As a result of flight, the digestive system of birds has become very efficient as to not burden the birds with extra weight to carry.
When a bird eats, the food is passed down the beak into the esophagus, a tube, that carries the food to a crop. The crop is a small sac wher food is stored until it can be deposited into the proventriculus. This is the first chamber of a birds stomach where the food is broken down by the digestive enzymes. The food is then passed into the gizzard, second chamber of the stomach, where the food is ground up. The food will then be released into the intestines where the nutrients are extracted for energy. When all the nutrients are absorbed, the waste usually gets deposited right on your car after you just cleaned it. Poop from the sky.
The earliest known bird is the Archaeopteryx which survived 150 million years ago. Birds evolved from the reptile species which today can be observed through many birds feet structure. Birds feet and legs are now used for walking, perching on limbs, and even tearing flesh from prey.
Birds beaks have also adapted to break hard seeds or rip flesh from prey.
Birds are an endothermic (regulate own body temperature) species and must consume a high quantity of food to maintain their body temperature. However, the respiratory system of birds is more efficient than of mammals although they both have a 4 chamber heart in common.
Birds are the only class of vertebrates to have feathers. The bone structure of birds is unique in that they are honey combed, very light weight, yet structurally sound to withstand the stresses of flight. As a result of flight, the digestive system of birds has become very efficient as to not burden the birds with extra weight to carry.
When a bird eats, the food is passed down the beak into the esophagus, a tube, that carries the food to a crop. The crop is a small sac wher food is stored until it can be deposited into the proventriculus. This is the first chamber of a birds stomach where the food is broken down by the digestive enzymes. The food is then passed into the gizzard, second chamber of the stomach, where the food is ground up. The food will then be released into the intestines where the nutrients are extracted for energy. When all the nutrients are absorbed, the waste usually gets deposited right on your car after you just cleaned it. Poop from the sky.
Reference
Twootz, "Bird Skeleton", retrieved from website April 13, 2013, http://twootz.com/article/Bird-Skeleton
Merriam-Webster, http://visual.merriam-webster.com/animal-kingdom/birds/bird/skeleton-bird.php
Henderson State University, Skeletal Adaptation of Birds,retrieved from website April 14, 2013, http://www.hsu.edu/pictures.aspx?id=1287
Henderson State University, Skeletal Adaptation of Birds,retrieved from website April 14, 2013, http://www.hsu.edu/pictures.aspx?id=1287