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 West Indies Birds of the West Indies Birds of the West Indies () is a book containing exhaustive coverage of the 400+ species of birds found in the Caribbean Sea, excluding the ABC islands, and Trinidad and Tobago, which are considered bio-geographically as part of South America. Written by ornithologist James Bond, the book was first published as "A Field Guide to the Birds of the West Indies" in 1936 by the Academy of Natural Sciences as part of the "International Series". It has been reprinted several times since then, including as one of the Peterson Field Guides series (PFG 18), a