Download CH 31 section 2 Birds foldable make n takes

BIRDS
Birds are animals that maintain a
constant internal body temperature.
They have an outer covering of
FEATHERS; TWO legs that are covered
with SCALES & are used for walking or
perching; and front limbs that are
modified into WINGS;
*NOT ALL
Ostrich, Emu,
Penguin!
BIRDS FLY!!
FEATHER
Structure made mostly of
protein that develops from a
pit in the bird’s skin. There are
two types of feathers:
CONTOUR Feathers (providing
lifting force & balance for
flight) & DOWN feathers (trap
air close to the birds body to
keep it warm).
Adaptations
HIGHLY efficient digestive,
respiratory, & circulatory
systems; aerodynamic
feathers & wings; strong
light-weight bones; &
strong chest muscles.
that allow
birds to fly
FEEDING
Small birds lose heat faster than a
larger bird, so small birds must eat
more relative to their body size.
Birds eat a variety of foods. Bird
beaks/bills are adapted to the
foods they eat.
CROP
Birds lack teeth & therefore cannot
break food down by chewing. Some
birds have a CROP. A crop is a
specialized structure that MOISTENS
& STORES food before it moves into
the GIZZARD or into the stomach. In
some birds the crop may (during
nesting season) break down cells
that produce a protein /fat substance
that is regurgitated & fed to young.
GIZZARD
Birds that eat insects or seeds have
a gizzard, which is a muscular organ
that helps to mechanically break
down food before it reaches the
stomach. The gizzard forms part of
the stomach.
RESPIRATION
Birds have a unique & highly efficient
respiratory system that allows a ONE
WAY flow of air which constantly
exposes the lungs to oxygen. This
allows birds to maintain a very high
metabolic rate.
CIRCULATION
Birds have a 4-chambered heart &
two separate circulatory loops.
RESPONSE
REPRODUCTION
Birds have well-developed sense
organs. Their brain can quickly
interpret & respond to a lot of
incoming signals. They have
excellent eyesight. Most species can
hear very well. The sense of smell &
taste are not well developed in most
birds (olfactory bulbs in birds are
very small).
Both the male and female
reproductive tracts open into the
cloaca. Bird eggs are amniotic eggs
with a hard shell. Most birds incubate
their eggs until they hatch.
GROUPS
OF
BIRDS
There are 30 different ORDERS of birds.
The larges order is the
PASERINES (perching birds).
Other groups of birds include:
Pelicans & their relatives,
Parrots; Birds of Prey; Cavity
Nesting Birds; Herons & their
relatives; Ostriches & their
relatives