Bird anatomy Birds have a four-chambered heart, in common with mammals, and some reptiles (mainly the crocodilia). This adaptation allows for an efficient nutrient and oxygen transport throughout the body, providing birds with energy to fly and maintain high levels of activity. A ruby-throated hummingbird's heart beats up to 1200 times per minute (about 20 beats per second). Many birds possess a muscular pouch along the esophagus called a crop. The crop functions to both soften food and regulate its flow through the system by storing it temporarily. The size and shape of the crop is quite variable among the birds. Members
Human uses of birds Human uses of birds Human uses of birds have included both economic uses such as food and symbolic uses such as art, music and religion, for thousands of years. In terms of economic uses, birds have been hunted for food since Palaeolithic times. They have been captured and bred as poultry to provide meat and eggs since at least the time of ancient Egypt. Some species have been used, too, to help locate or to catch food, as with cormorant fishing and the use of honeyguides. Feathers have long been used for bedding, as well as for quill pens and