Gallus domestica

CLASS AVES

CLASSIFICATION

Kingdom: Animalia

Phylum: Chordata

Class: Aves

Order: Galliformes

Family: Phasianidae

Subfamily: Phasianinae

Genus: Gallus

Species: Gallus gallus

Subspecies: G. g. domestica

GALLUS GALLUS DOMESTICA

EXTERNAL PARTS OF THE CHICKEN

CHICKEN EYES AND NOSTRILS

Eyes

attached are also much bigger than in mammals such as humans.

Orbits are made of many small bones that merged together. They made a thin plate.

Nostrils

Located at the end of the beak

EYELIDS

Chickens have 3 eyelids:

upper eyelid

Lower eyelid

Nictitating membrane

NICTITATING MEMBRANE

transparent or translucent third eyelid

can be drawn across the eye

for protection and to moisten it while maintaining visibility

to protect the parents' eyes from their chicks while they are feeding them

BEAKS AND EAR OPENINGS

Have a pointy beak for picking up food

No teeth are present Located at the sides of

their head behind the eyes

covered by feathers

are more like ear holes

No outer ear, or pinna

They have visible ear lobes

It is believed that the same gene that determines the color of the ear lobe also determines egg color.

Their ear lobes also can be colored from near white to near black. These birds will lay eggs that are nearly white to a deep, soft brown. The shade of brown of the egg will be indicated by the degree of color of the ear lobe. In other words, a chicken with blackish lobes will not lay a black egg, but it may be a deep brown.

WATTLE

Wattles are located under the chin.

They are meaty, red growths.

Both male and female chicken have wattles.

wattles cools down the chicken.

This happens when the blood circulates from the comb to the wattles. The circulating blood lowers the temperature of the chicken during the hot weather.

COMB

fleshy protuberance on top of the head of a chicken

the cockerel have a larger comb than the hen chicken

act as a cooling mechanism for the birds

large combs on males attract females as chickens can detect colour and are very attracted to the colour red.

serves as an indicator of the bird’s health.

TYPES OF COMBS

THE FORELIMB

THE FORELIMB

The bird’s wing and is responsible for powered flight.

Primarily supported by an elongated radius, ulna, and modified wrist bones.

THE FORELIMB

THE FORELIMB

Upper Arm

Short and stout humerus

Connects the scapula with the lower arm (or forearm)

Provides the musculature necessary for flight

THE FORELIMB

THE FORELIMB

Forearm

Composed of an elongated radius and ulna

Serves as attachment point for flight feathers

Reduced wrist flexion

THE FORELIMB

THE FORELIMB

Manus

The phalanges of the bird wing follow a trend of reduction and fusion to form the distal part of the wing

Modern birds have mostly only the second digit of the hand present

THE FORELIMB

THE HINDLIMB

THE HINDLIMB

Composed of the thingh, shank and foot.

Enables bipedal locomotion for birds.

THE HINDLIMB

Thigh

Upper portion of a bird’s hindlimb

Composed of a short femur.

THE HINDLIMB

THE HINDLIMB

Shank

Lower portion of a bird’s hindlimb

Composed of the tibiotarsus (fused tarsus and proximal part of the tibia).

THE HINDLIMB

FOOT AND REMIGES

FOOT

1. Hallux or hind toes

2. Inner toe3. Middle toe4. Outer toe5. Scales6. Reticulate

scales

REMIGES

PTERYLAE

Region on the chicken skin where feathers grow

Symmetrical tracts

Separated from each other by semi-apteria

Feather macropattern

APTERIA

Bare area(feathers don’t grow) on the chicken skin

Spaces between the feather tracts of birds

Covered by down or semi-plume feathers