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
Birds of the Amazon Birds of the Amazon An immense number of bird species live in the Amazon rainforest and river basin (an area which is nominally home to one out of every ten known species of animal). Over 1,300 of these species are types of birds, which accounts for one-third of all bird species in the world. The diets of rainforest birds greatly differ between species, although, nuts, fruits and leaves are a common food for many birds in the Amazon. Birds migrate to the Amazon rainforest from the North or South. Amazon birds are threatened by deforestation since they primarily reside in