Birds
Ch. 4 Sect. 1
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Vocabulary Words
• Aves• Ornithology• Contour Feathers• Down Feathers• Preening• Crop• Gizzard
• Gastroliths• 4 Types of birds• Archaeopteryx• Protoavis
Classification
• Kingdom: Animalia
• Phylum: Chordata
• Class: Aves
• The study of birds is called Ornithology
Bird Characteristics1. Flight adaptations
– Flight is made possible because of their:• Strong but lightweight skeletons• Wings• Feathers• Strong flight muscles• Efficient respiratory system• Ability to quickly convert food into energy• Well developed senses (especially eyesight)
Lyre Bird
2. Hollow Bones– Most bones of birds that fly are almost
hollow• These bones have thin cross braces inside that
strengthen without adding weight. • The hollow spaces are filled with air
– Many bones are joined together for added strength
– Large sternum (breastbone) to support chest muscles need for flight
– Last bones in the spine support the tail feathers which are needed for steering and balancing
• Birds do NOT have bones in their tails
3. Feathers– Birds are the only animals that have feathers– Two types of feathers:
1. Contour Feathers– Strong, lightweight– Give the bird its coloring and smooth shape– Flight feathers– Developed after hatching
2. Down Feathers– Soft, fluffy– Developed before hatching (baby birds are born with
these)– Adults have them underneath their contour feathers– Work as insulation to help birds maintain their body
heat
– Preening • Birds have oil glands by the base of their tails• Using their beaks birds rub oil from this gland over
their feathers. • This oil makes their feathers water-repellant
Body Systems• Reproduction
– Internal fertilization– Lay amniotic eggs
• Eggs are typically laid in a nest• Group of eggs = clutch• Incubated (kept warm) by one/both parents
– Incubation period varies by species
• Young are cared for by one/both parents after they hatch
• Digestive System– Flying requires large amounts of energy to
supply this energy a bird’s digestive system changes food into energy very quickly
• Ex. Some birds can digest food in 1 hour Humans can take 24 hours to digest food
– Birds have powerful beaks for crushing but no teeth
Passage through a Bird’s digestive system:1. Mouth2. Crop
- Food waits here to absorb enough moisture to move on
3. Stomach- Food is partially digested
4. Gizzard- Food is ground and crushed by small stones the bird has swallowed- These stones are called gastroliths
5. Intestines6. Nutrients move into the blood stream and wastes
are secreted out the cloaca
The gizzard of a loonWARNING: This is kind of icky.
Can you spot the gastroliths?
• Respiratory System– Birds are endotherms
• Endotherms maintain their own internal body temperature
– Birds have two lungs• Each lung is connected to balloon-like air sacs that
reach into different parts of the body• Most of the air inhaled by a bird passes directly
into the air sacs behind the lungs• When a bird exhales the air with oxygen passes
from the air sacs into the lungs• This means that birds get oxygen when they inhale
and exhale!
• Circulatory System– Large 4 chambered heart
• Ex. A sparrow’s heart is 1.68% of its body weight a humans is only 0.42%
• The four chambers keep oxygenated blood separate from carbon dioxide blood.
• Bird’s hearts beat very rapidly– A hummingbird’s heart can beat over 1,000 times per
minute! The average human’s resting heart rate is only 72.
Groups of BirdsThere are 4 main groups1. Flightless Birds
- Ex. emu, ostriches
2. Water Birds
- Ex. swans, flamingos
3. Birds of Prey - Ex. owls and hawks
4. Song Birds
- Ex. cuckoo, nightingale
Kingfisher – A Bird of Prey
What we see What a fish sees
King Fisher
The Importance of BirdsBenefits:• Food• Raw Materials (ex. feathers)• Pets• Pest Control
– Ex. Owls eat mice
• Pollinators– Pollen is transferred from flower to flower by their feathers– Seeds can also be dispersed in their droppings
Negatives:• Droppings can damage buildings/cars • Their waste can contain harmful microorganisms
Origin of Birds• Scientists hypothesize that birds
developed from reptiles millions of years ago
• Archaeopteryx is the oldest birdlike fossil– 150 mya– Solid bones, teeth, bony tail
• Protoavis– 225 mya– Hollow bones, well developed sternum, teeth– May have been the first species of birds
Grouping Birds• Birds in general - A flock of birds
–Chickens - A peep of chickens –Crows - A murder of crows –Ducks - A paddling of ducks –Falcons - A cast of falcons–Parrots - A company of parrots –Swans- A ballet of swans–Turkey – A rafter of turkeys
The End!