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
Methods used to study memory use single cell recordings solely for experimental purposes is exclusive to animal testing and has greatly increased our understanding of memory systems. Comparisons of the neuroanatomy of caching and non-caching birds has shed light on the neural basis of spatial memory. David Sherry and his colleagues devised experiments using the displacement of landmarks, to show that caching birds rely on spatial memory and landmark cues to find their caches, and local changes in cache appearance had no effect on food retrieval. They were able to show that changes in neurogenesis are directly related to food storing behavior. Food caching behavior