By Hillary GoinsZoologyMrs. Guy8th Period

Birds

Where Did Birds Come From? There are approximately 8,600 species of birds that belong to class Aves Scientists claim that birds emerged from theropod dinosaurs

Theropod dinosaur Blue bird

Characteristics of BirdsFeathers

Birds are the only living organisms with feathers.

Feathers help to keep the birds body temperature regulated and feathers also assist in flight.

“Preening” is a way that birds care for their feathers. Their bill is very similar to a comb in this process.

Feathers get worn after time and the birds shed them just as snakes shed their skin. This process is called “molting”. This usually occurs towards the end of summer.

Feathers usually shed in pairs so that the process doesn’t interfere with flight.

Wings are an adaptation that are necessary for flight.

Birds have a breastbone that is called the sternum. The muscles are connected to this bone and they are also attached to the upper bone

of each wing.

This bone is important because it reinforces the push and force that is necessary for birds to lift their bodies off of the ground.

Wings

EnergyBirds have a four-chambered heart which beats fast and moves oxygenated blood throughout the body. Good circulation is needed to supply cells with oxygen, which in turn, gives the bird the energy necessary for flight.

Birds have a respiratory system which gives oxygen to the lungs both when it inhales and exhales. The respiratory system is made up of lungs and anterior and posterior air sacs.

WHAT IS NECESSARY FOR FLIGHT?

Birds are endothermsWhat does that mean?

Endotherms keep a consistent body temperature which is not affected by the temperature of the environment.

This allows birds to live in all environments, however, they must eat lots of food in order to keep up the levels of energy they need.

How do birds reproduce?•Birds reproduce by internal fertilization.

•Birds lay eggs that are covered with a hard shell. The eggs are laid inside a nest which is made up of twigs and straw.

•Bird eggs are unique and can often be categorized by the color, size and shape of the eggs the bird lays.

•Birds incubate, or sit on their eggs, to keep them warm.