Chapter 27 Chordata- Birds

Feathers

modified scales made of keratin to provide lift and preserve body heat

Quill

base, grow from follicles

Ranchis

center shaft

Barbs

branches off the ranchis

Vane

flat, webbed surface of barbs

Barbules

microscopic hooks between barbs

Contour Feathers

flight and form

Down Feathers

under contour feathers, for insulation

Filoplume Feathers

hair-like degenerate feathers with a weak shaft and tufts

Powder Down Feathers

disintegrate to release talc-like waterproof powder

Molting

shedding feathers and growing new ones

Pneumatized Bones

laced with air cavities

Vertebrae

most except for cervical vertebrae are fused to move neck for sight

Pectoral Girdle

connects wings to the sternum

Sternum

large breastbone to attach flight muscles

Pygostyle

fused lower vertebrae to support tail for lift and breaking

Pectoralis Muscles

depress wings during flight

Supracoracoideus muscles

raise the wing with rope and pulley arrangement

Proventriculus

first chamber of stomach, secretes acid and digestive enzymes

Gizzard

second part of stomach, contains small rocks the bird has swallowed, for grinding food

Crop

first section below esophagus, stores food waiting to be digested

Colic Caeca

where small and large intestines meet, contains bacteria to aid in plant digestion

Cloaca

where digestive waste is mixed with uric acid containing urine

Air Sacs

provide more oxygen during flight, decrease density

Migration

to exploit seasonal changes, expand living space, reduce territorial aggression

Infundibulum

first part of the oviduct, special glands inside add the albumen of the egg

Albumin

egg white, 2/3 of the egg

Monogamous

one partner for each breeding season

adaptions for flight

Wings for support/propulsion, respiratory, circulatory and digestive systems to meet high oxygen demands and respiratory system cools body, light and rigid bones, superb sensory structures in nervous system

preening

rubbing feathers with oil secreted by the preen gland to zip the barbules back together

types of molting

lost in pairs, some molt continuously to keep flight, water birds may molt all at once, birds in temperate climates molt their flight feathers in late summer after nesting season

how is the skeletal system unique

strong, light and delicate bones, skull fused to one piece, keratinized beak around bony jaws, pneumatized bones

bird feeding determination

beak shape

food quantity and metabolic rate

need lots of food compared to their weight for high activity flight

respiration

air sacs store air, during inspiration air goes through to posterior air sacs into lungs, for expiration the air is in the lungs and is pushed into the anterior air sacs, then out

how are testes and ovaries unique

testes enlarge up to 300 times during breeding season, ovaries and oviducts on only one side work, usually left

path an egg takes

fertilized in upper oviduct, infundinulum for the albumen, travels down the oviduct to gain shell and shell pigments, cloaca, vent

precocial young

can walk, swim, and feed themselves soon after birth

atrical young

featherless, blind, helpless and need heavy parental care

circulatory

4 chambered, inversely proportional heart, fast heartbeat

Elliptical wings (flycatcher bird)

large wing slots, broad, alula, wide but pointed

High aspect ratio wings (swallow)

slender tip, no wing slots, sweepback boomerang shape

Dynamic soaring wings (albatross)

no wing slots, long, narrow and straight

High-lift wings (hawk)

broad wing, wing slots, alula, wide square ish shape