Pigeon - semi domesticated birds and living symbol of peace

Living symbol of Peace

 

GENERAL FEATURES

It is cosmopolitan in nature.
It is a gentle bird.
It reffered to be the "Symbol of peace."
It exhibits social behaviour.
They fly in flocks and roost( a place where birds are going to sleep ) together.
It is monogamous and the partnership is lasts for entire life.
It is zoological name is Columba livia.It is commonly called rock pigeon.
It shows the sexual dimorphism.(we can identified the sex easily).
It is graminivorous in nature i.e., it intakes the grains as a food materials.
Each  clutch has 2 eggs.Both sex takes the care over the youngones.
The incubation period for nestlings are 17 days.

      —  Body (spindle)-head,neck,trunk and tail.

—  Elongated jaws-beak/bill.(upper and lower beak).

—  Rhampotheca-a horny sheath covered the beak.

—  Upper beak-base-2 external nostrils.

—  3 eyelids-upper ,lower and third eyelid(nictitating membrane).

—  2 ear openings-external auditory meatus.

—  Forelimbs-modified into wings.

—  Hind limbs-thigh,shank and foot.

It consists of several system…

   Skin and Exoskeleton

—  Digestive system

—  Circulatory system

—  Respiratory system

—  Flight muscles

—  Nervous system

—  Excretory system

—  Reproductive system

—  Skeletal system

Skin

Thin and dry.
No skin glands.
2 layers.

EPIDERMIS	DERMIS(connective tissue)
Outer layer-Epitrichium	Nerves
Middle-Stratum corneum	Blood vessels
Inner – Stratum Malphighii	Muscle fibres

Exoskeleton

Beaks	Feeding,preening,fighting
Claws	Perching and walking
Scales	Cover the lower part of the hind limbs.
Feathers	Nature’s masterpiece

Pterylosis-arrangement of feathers on the body.
Pterylae-arranged in tract form.
Apteria-featherless area.

Pigeon has 4 types of feathers.

Quill feathers	Remiges(23) -wings, Rectrices(12)- tail region, Coverts –cover the bases of remiges and rectrices, Contours (entire surface).
Filoplumes	Clearly seen in plucked birds.
Down feathers	Seen in nestlings.
Rictal bristles	Located in the base of the bill.

Digestive System

(Alimentary canal and digestive gland

—  Mouth

—  Buccal cavity

—  Pharynx

—  Oesophagus

—  Crop(pigeon’s milk)

—  Stomach

—  Gizzard

—  Small intestine

—  Large intestine

—  Cloaca 

   Circulatory system Blood
—Plasma and corpuscles(RBC and WBC).
—No platelets.
—RBC-oval, nucleated.
—WBC-lymphocytes,monocytes,basophils,eosinophils and neutrophils.
Heart —Muscular pumping organ.
—Conical shape.
—Double layered membrane-pericardium.
—Pericardial cavity- Pericardial fluid.
—4 chambered.
—Double circulation i.e.,oxygenated and deoxygenated blood.
—Heart beat -190 times/minute.
—Contraction-systole and relaxation-diastole.
Arterial system ,venous system and portal system Arterial system —Carry the blood from the heart to the various parts of the body.
Venous system —Carry the blood from the various parts of the body to the heart. Portal system —Carry the blood from one organ to the other organ.
—2 types
—Hepatic portal system(blood from alimentary canal to liver).
—Renal system(blood from posterior part of the body to kidney).
Respiratory system (pulmonary respiration) —External nostrils(base of the upper beak)
—Olfactory sacs
—Internal nostrils
—Buccopharngeal cavity
—Glottis
—Trachea
—Larynx
—Primary and secondary bronchi
—Air sacs
—9 air sacs —2 cervical air sacs
—one median interclavicular air sac
—2 anterior thoracic air sacs
—2 posterior thoracic air sacs
—2 abdominal air sacs
Flight muscles

—Muscles used for flight-flight muscles.
—Pectoralis major(downstroke)
—Pectoralis minor(upstroke)
—Coraco brachialis longus(rotation during the flight)
—Coraco brachialis brevis(rotation during flight)
—Extensor carpi radialis(fore arm)
—Extensor carpi ulnaris(fore arm)
— Tensor longus (prepatagium stretching process in flight)
— Tensor brevis (prepatagium stretching process in flight)
—Tensor accessorius (prepatagium stretching process in flight)
—Tensor posterious (postpatagium stretching process)
—Biceps (upper arm)
—Triceps(upper arm)

Nervous system Central nervous system —Brain and
—Spinal cord
Peripheral nervous system —Cranial nerves and
—spinal nerves
Autonomous nervous system  Sense organs —Tactile organs (sense of touch).
—Taste buds (sensory cells and supporting cells)
—Olfactory organs (sense of smell).
—Eyes (photoreceptor).
—Ears (hearing and equilibrium).
Excretory system

—Metanephric type(Gr.meta=after,nephros=kidney)-located in posterior region.
—Flattened dark red kidney.
—Semisolid urine(excreted along with feacal matter).
—Uric acid –guano(droppings of birds).
— Skeletal system

Skull —Autostylic(Gr.auto-self,stylos-pillar).
—Formed of pneumatic bones.
—Fused bones ,No sutures
—It consists of cranium,olfactory capsules,auditory capsules,optic capsules,upper jaw,lower jaw,hyoid apparatus(tongue).
Vertebral column  —Cervical-14
— Thoracic-5
—Lumbar-6
—Sacral-2
—Caudal-11

Ribs —7 pairs
—Cervical-2
—Thoracic-5
Appendicular skeleton

Girdles —Pectoral girdle
—Pelvic girdle 

Limbs

—Fore limbs

   Upper arm,fore arm and hand

—Hind limbs

    Thigh ,shank and foot Reproductive system
Reproductory system

Sexes are separate.
Exhibits sexual dimorphism.
Male reproductory system.
Female reproductory system.
Male Reproductive system —Pair of testes
—Testes attached to the kidney – mesorchium.
—Testis- numerous tubules –seminiferous tubules.
—Vasadeferens coiled tube arised from testis.
—Vasadeferens run backward to open into urodeaum of the cloaca.
—Posterior end of vasdeferens is slightly dilated to form seminal vesicles.
FemaleReproductive system
—Single ovary on the left side.
—Attached to the kidney –mesovarium.
—Only one oviduct
—Oviduccal funnel/ostium-anterior end of oviduct opens into the body cavity through a funnel.
—Oviduct is differentiated into magnum,isthmus,uterus,and vagina.