Cockatiel Anatomy

Bones

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As birds must be very light to fly easily, their bones are hollow.

Cockatiel’s sternum is rather flat, but the other side has developed to protruding mane, attached to the chest muscles. If you can’t feel the sternum, the cockatiel is probably overweight. If you can feel it too clearly, the bird is probably too skinny. Because there are five lumbar vertebrae fused together, and the breast is not very flexible either, the back of the cockatiel isn’t really bending. Instead, the neck is very flexible, and a cockatiel usually sleeps the head turned backward, beak embedded in the back feathers.

The skull is attached to the vertebra with one condyle and is formed from bones that are fused together. The mission of the skull is to protect the brains that are located inside the round shaped braincase. The eye sockets are very large. The length of the skull is around 2,2-2,7cm.

Cockatiels don’t have teeth. Instead, they have a beak. The tail is attached to a stub tailbone called the pygostyle. The forelimbs are developed through evolution and formed as wings. Looking at the wing bone structure, you can see same elements as the human hand would have. It is noticeable, for example, that the wing has three fingers: the thumb, middle finger and ring finger, although these are clearly atrophied.

The legs and feet have developed for multitasking. Cockatiels use their feet to move, sit, scratch and catching objects. The femur is very short, and the knee is hidden among the feathers. The tibia and instep are longer parts of the birds. So, unlike mammals that use mostly the knee to refract their legs, birds use their ankle.

An integral part of the structure of the foot is the “intertarsal bend,” which is a fusion of the ankle bones of the calf and shin bone. Intertarsal bend, therefore, is located in the center of the ankle. It’s that larger “ball” of the leg that resembles a knee turned just to opposite direction. The whole foot structure is made for agile climbing.

Digestion

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1. Esophagus or gullet
2. Crop
3. Proventriculus
4. Gall bladder
5. Large intestine
6. Rectum
7. Anus or Vent
8. Cloaca
9. Kidneys
10. Pancreas
11. Spleen
12. Liver
13. Ventriculus or gizzard
14. Lungs
15. Small intestine
16. Brains
17. Spinal column
18. Thyroid
19. Trachea

Respiratory

The parrot respiratory system, divided in lungs and air bags, is very highly developed. The system serves well the capability to fly. Their gas exchange is really effective.

The trachea divides into two bronchi. The lungs themselves are small and spongy-like. One of the interesting characteristics of the respiratory system are the air sacks. Their mission is to dissipate liquids and restore gasses that the bird breathes. As the liquids dissipate, the cockatiel can somewhat control the body temperature and prevent it from rising too much. A bird breathes, air flows through the lungs to the air sacks in the tempo of the movement of the ribs and sternum – going through the vasculature twice. As the bird flies the muscles moving the wings cause the air sacks to wide and shrink and this causes the air rotation and changing from the lungs.

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Neitokakadu

A cockatiel needs a good respiratory system and good muscles to fly.
Photo: Shutterstock / Omepl1

Sight

As all the birds do, cockatiel has a brilliant sight. It is much better than we humans have. Their eyes work without depending on each other. Picture reflecting the retina is huge and bright. The fact that the eyes are positioned to the sides of the head means that the field of vision is wide. A small blind spot forms to the very front and back of the head but this little “flaw” is replaced with a very bendable neck.

Humans have trichromatic vision. This means that we have three types of pin cells. Parrots have tetra or even pentachromatic vision, meaning that they have at least one pin cell type more than we do – and this means that they can see a whole color dimension that we can’t. Whereas a human can see red, green and blue light, parrots see red, green, blue and ultraviolet light reflections. So, they can see the UV colors. It is also doubted that they may see even colors we aren’t even aware of. Bird’s cornea passes through the near UV up to 230 nm. Shorter waved UV would be already dangerous (Viitala, 2003). UV color perception will be introduced, especially regarding a feather suit. Feather costumes have different UV absorbers, as well as the reflective patterns, which may be relevant, for example, when it comes to choosing a mate. Ultraviolet colors matter when choosing what to eat. To improve the vision of your cockatiel that lives indoors, you absolutely have to have a bird lamp that is a UV lamb designed to serve the parrot’s vision.

The bird lamp affects to…
– Perception of movement
– Communication
– Calcium absorption
– Eating
– Juvenile sex ratio

Cockatiels can detect 1,200 pictures in a second (Forbes, 2007), comparing to humans who can see about 20 pictures per second and even less in dim light. To guarantee that your bird can use the whole seeing capability, remember to provide the bird lamp. Yes, your cockatiel can “live” without it but not as happy as with it. Especially if your cockatiel keeps screaming all the time it might be wise to see that you use a proper UV lamp: the screaming might be caused by flashing fluorescent light that makes the bird very nervous.

Sources:
Häkkilintujen tutkiminen, sairaudet ja hoito, 1991, Eläinlääketieteellinen korkeakoulu, Opintomonisteita 13 (Kristiina Kontio-Jalanka, Harry Jalanka