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 World: Recommended English Names some 80% of the world's species and is still sometimes controversial. A number of authors have come up with lists of birds of the world, but none had as its primary goal the standardization of names. As a result, the field of English names of birds was left "a swirling sea of polylexy and polysemy, where one bird may have many names and one name may apply to many birds." In the late 1980s, the International Ornithological Congress (IOC) sought to reach consensus in standardized vernacular names for commonly used languages. Standardized names were published for French in 1993 and