What characteristics do all birds have in common?

All birds… Are vertebrates Are endothermic Have feathers Have a four-chambered heart Lay eggs

The bodies of most (but not all) birds are adapted for flight

In order to fly birds need… 1) Hollow bones to make the bird lightweight

In order to fly, birds need… 2) large chest muscles to move their wings

In order to fly, birds need… 3) Feathers ---they are the only animals to have feathers

Different kinds of feathers: Contour Feather: one of the large feathers on a bird that gives shape to a bird’s body Flight Feathers: long contour feathers that extend beyond the body on the wings and tail Help the bird to balance and steer Contour feathers in general have a central shaft and projections called barbs Down Feathers: short, fluffy feathers that are specialized to trap heat and keep the bird warm Found right next to the bird’s skin at the base of the contour feathers Are soft and flexible

Feathers Contour Feathers Down Feathers

Feathers

Obtaining Food

Birds must obtain a lot of food to provide the energy needed for flight

Because they need energy for flight and they are endotherms, birds need a lot of food. Each day, the average bird eats food equal to about a quarter of its body weight This is why the phrase “You’re eating like a bird” is incorrect….bird eat a lot!

What do birds use to capture, grip and handle food?

Bills – shaped to help birds feed quickly and efficiently A bird’s bill is shaped depending on what it eats

Example: The pointy, curved bill of a hawk acts like a meat hook to pull off bits of its prey

Example: A duck’s bill acts like a kitchen strainer, separating out seeds and tiny animals from muddy pond water

Example: Pelicans need a large bill to scoop fish out of the water

Birds have special organs to digest food

2 organs that birds have that humans do not are a gizzard and a crop

Crop: an internal storage tank for storing food inside the body after swallowing it A muscular pouch near the throat

Gizzard

Gizzard: a thick-walled, muscular part of the stomach that squeezes and grinds partially digested food Birds have one to make up for the fact that they do not have teeth! The gizzard does the same grinding function for birds that your teeth do for you

Keeping conditions stable Being endotherms, birds need to keep warm To maintain their body temperature, they use energy from food and feathers to trap heat Down feathers are specialized to trap heat, as they are found right next to a bird’s skin

Birds Reproduction Have internal fertilization Lay amniotic eggs In most species, a female lays eggs in a nest Bird eggs will only develop at a temperature close to the body temperature of the parent bird A parent bird usually incubates the eggs by sitting on them to keep them warm Parents take care of their babies until they learn how to fly