31-2 Birds
*Ornithology is the
study of birds
Characteristics
1. Forelimbs modified into wings
2. Feathers
3. Hollow, lightweight bones
4. Endothermic
5. Efficient respiration
6. Heart with a completely divided ventricle (4
chambers)
7. Scaley feet (birds are related to reptiles)
8. Furculum (wishbone)
Classification
Kingdom Animalia
---Phylum Chordata
------Subphylum Vertebrata
---------Class Aves
Aviation = flight
Types of feathers
Down feathers - provide insulation
* birds are endothermic
Contour feathers - cover head and
body, provide coloration
Flight feathers - on wings and tail,
● Feathers are covered in oil to keep them
water proof - "like water off a duck's back"
- this oil is secreted from a preen gland
● Preening is a behavior that replaces the oil
on feathers, and repairs broken links on
the vanes
Evolution of Birds (from reptiles)
● Archaeopteryx - “ancient wing”
● Reptile like - Had teeth in beak,
bony tail, claws on wings
● Bird like = Had feathers,
& fused collarbone
(wishbone)
Adaptations for flight:
● Efficient digestive, respiratory, and
circulatory systems
● Aerodynamic feathers and wings
● Strong, lightweight bones
● Strong chest muscles
FEEDING
-- shape of the beak
related to food
Examples:
Hooked beaks used
for tearing meat
Long sharp beaks for
spearing fish
The shape of a
beak and type of
feet a bird has
can tell you much
about its lifestyle
What do you think
this bird eats?
How does its feet
help it in its
habitat?
Digestive System
● Birds lack teeth
● Crop stores and moistens food
● Gizzard grinds the food
Some birds will use their
beaks to tear food into bits,
most of these chunks of
flesh are swallowed whole
Mouth esophagus crop stomach/gizzard
small intestine large intestine cloaca
Other systems
Respiration
● Mouth trachea air sacs and bones
lungs
● A one way flow of oxygen
Circulation
● 4 chambered heart (double-loop system)
Excretion
Nervous System - response
● Well develop sense organs
● A large brain
● Cerebrum = thinking, decision making
● Cerebellum = coordinated movement
● Medulla oblongata = basic body process
● Optic lobes = vision
● Olfactory lobes = taste and smell
Movement
● Flightless (ostrich, penguin…etc)
● Forelimbs modified for flight = wings
● Collarbones are fused making a strong base
for flight muscles - fused bone is the
furculum
● Air spaces make the bones light in weight
● Strong chest muscle attach to a keel of the
sternum (breastbone)
Reproduction
● Internal Fertilization + Amniote Egg
● Incubation
● “egg tooth”
Many baby birds are
born helpless and
without feathers. These
baby birds require lots
of care from their
parents.
Some babies hatch with feathers and can follow
their mom around, swim and eat on their own.
Some babies IMPRINT on the first thing they see.
Bird Myths
If you touch a baby bird, the mother won’t
take it back
Reality – most birds have a poor sense of
smell, there may be other reasons why mom
has rejected the baby
Turkeys can’t fly.
Reality - wild turkeys can fly, just not long
distances. Another myth is that turkeys
drown in the rain, that one is also untrue.