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
The Birds of the District of Geelong, Australia The Birds of the District of Geelong, Australia The Birds of the District of Geelong, Australia is a book published in 1914 by W.J. Griffiths in Geelong, Victoria, Australia. Authored by Charles Frederic Belcher, it was published in octavo format (225 x 144 mm), containing 414 pages bound in navy blue buckram. It is illustrated with numerous black-and-white photographic plates. It contains a systematic list of 244 bird species known to occur within a radius of from the city of Geelong, south-west of Melbourne on the western side of Port Phillip Bay, followed by largely personal reminiscences on the birdlife.