Bird Dissection

INTRODUCTION: The bird is a vertebrate whose body plan is adapted to its requirements for flight.For example, the skeletal system is lightweight and very strong.The flight muscles of the chest may make up one fifth of the total mass of a bird's body.Birds have extremely great energy requirements because of their high metabolic rate.The unique air sacs of their respiratory system provide them with a continuous supply of oxygen.In line with their needs for a streamlined, lightweight body, birds' reproductive organs are small and inactive for most of the year.During the breeding season, however, the male and the female reproductive organs increase greatly in size.

PURPOSE:In this investigation, you will be exploring some of the unique structural features of a bird through a dissection.The bird under study, found in great numbers in North America, may be either a pigeon or a sparrow.

CLASSIFICATION:††††† Kingdom: Animalia††††† Phylum: Chordata††††† Class:Aves

MATERIALS NEEDED:preserved specimen /probe /dissecting tray / forceps/scissors /hand lens / scalpel or razor blade

PROCEDURE:††††† Obtain a preserved bird.Place the ventral side up in a dissecting tray.




For an animal to use food as fuel, it must digest the food - break it down small enough to be absorbed into the bloodstream - and get rid of the waste products. A bird's gut looks much like your own, but there are some differences. Many seed and grain-eating birds have a crop connected to the esophagus. The expandable crop allows birds to quickly gather and store a large amount of food, then retreat to safety to digest it.

digestive system


Lungs exchange oxygen and carbon dioxide between the blood and air. Bird lungs are smaller than those of mammals, yet they are part of the most efficient respiratory machinery known in vertebrates. Even with this efficient respiratory system, birds breathe rapidly during flight - up to 450 breaths per minute for a pigeon.

Unique to birds are air sacs. Air sacs act as a bellows to suck air into the body, then circulate it in a one-way flow through the lungs - giving the lungs a constant flow of fresh air.

The nine air sacs also act as a cooling system since birds do not have sweat glands. They contribute to stability in flight by lowering the center of gravity and act as shock-absorbers in diving birds, such as Brown Pelicans. During courtship, male grouse inflate special air sacs on their chests like brightly colored balloons to attract a mate.


A bird's heart is much like yours - a four chambered muscle that pumps blood throughout the body. A bird's heart weighs up to twice as much as that of a mammal of equal size because flying is strenuous. Energy-hungry muscles need a bigger, faster beating heart to send them plenty of oxygen and nutrients. Smaller birds and mammals lead fast-paced lifestyles and generally have faster heart rates than large ones.Hummingbird 600 beats per minute at rest, Pigeon 200 beats per minute at rest, Ostrich 65 beats per minute at rest, Human 70 beats per minute at rest.



Birds are known for their fast reactions, balance, coordination and instinctive behavior. Bird brains are relatively larger than those of reptiles but smaller than those of mammals. Birds are not known for reasoning abilities however, some birds do have significant learning abilities, such as parrots trained to talk or do tricks.

bird brain