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
Regulation of food and dietary supplements by the U.S. Food and Drug Administration whether it is to be regulated as a food or as a drug, based on the claims that the manufacturer or seller makes about its properties. The FDA is authorized to issue a standard of identity for any food. This is a description of what, exactly, must be in that food in order for it to be identified under a certain name. For example, a court has upheld an FDA ruling that for a product to be sold as cream cheese, it must contain a specified minimum percentage of milk fat, and a maximum level of moisture. Incorrectly identifying a