final report visual psyche

8/2/2019 Final Report Visual Psyche

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What is a Parrot?

Parrots, also known as psittacines are birds of

the roughly 372 species in 86 genera that

make up the order Psittaciformes, found in

most tropical and subtropical regions.



Features:

Characteristic features of parrots include a

strong, curved bill, an upright stance, strong

legs, and clawed zygodactyl feet. Many parrots

are vividly coloured, and some are multi-

coloured.



Parrots are mainly seed, nut and fruit eaters,

augmenting their diets with a few insects for

protein. They are usually found in flocks,

which accounts for their sociability and need

for human contact in captivity. They mate for

life and are capable of bonding strongly with

their owners.



Parrots, along with ravens, crows, jays andmagpies, are among the most intelligent birds,

and the ability of some species to imitate human

voices enhances their popularity as pets.

Parrots do not have vocal cords, so sound isaccomplished by expelling air across the mouth

of the bifurcated trachea. Different sounds are

produced by changing the depth and shape of

trachea.



What is a lovebird?

A Lovebird are pint-sized bundles of joy. Theyhave the full personality of parrots while beingeasy to house because of their size. A lovebird is

one of nine species of the genus Agapornis(Greek: agape 'love'; ornis 'bird').They are a social and affectionate small parrot.

The playful and very inquisitive nature plus the

small size of the species Agapornis make them avery ideal pet especially when they have beenhand raised.



Characteristics

The lovebird is a short, thick-bodied parrot

and is about 5 to 6 inches long from head to

tail. A lovebird has a relatively large beak for

it's size and the basic color of the species is

green.



Their name stems from the parrots' strong,

monogamous pair bonding and the long

periods which paired birds spend sitting

together. Lovebirds live in small flocks and eat

fruit, vegetables, grasses and seed.



It is important to realize that while lovebirds

are a small parrot, they have the intelligence

and abilities of some of the largest parrots.

And they can learn to mimic sounds and

speech on occasion.



Why call them lovebirds you ask?

Well they were named lovebirds because if

kept in pairs the lovebirds will constantly

groom each other and sit as close together as

possible when sleeping or resting.



The Mirror Game They fly up to their

reflections in the mirror to watch themselves

fly, then land, then the other one goes. They

never hit the mirror and can play this game

forever without getting tired.



Parrots Eye

Facial shape and eye shape

Parrots are narrow-faced, day-active birds, so

their eye bulb is flat and shallow and set at theside of the head.

This leads the parrot to see only with one eye at atime (monocular field of vision).

They have better lateral visionthan they do frontal vision and they takeadvantage of "monocular"vision for that reason.



The field of vision where a parrot sees stereowith both eyes is only about 6-10°. In return, it

gives them a field of vision close to 360°, so theycan see most of what happens in front, behind, above and below them.

In addition, parrots can move their eye bulbs in

the sockets (not all birds can), which allows themto look around without moving as a protectionfrom predators.



Scleral Ring

Unique to birds (and some reptiles), the sclera

ring is a bone structure around the lens. It

protects the eye bulb (especially in birds with

a shallow eye socket) and helps with the

accommodation of the lens to focus on

objects.



Iris

In birds, the muscles attached to the iris are

striated, so the bird can actually control opening

and closing the pupil. This allows much faster

adaptation to bright and dark (e.g. during flight).

birds "pin" their eyes or also known as Eye

pinning when they are excited. Parrots often

rapidly dilate and constrict theirpupils when they are being aggressive or are

excited.



Pecten oculi

This structure at the back of the eye where

the visual nerve enters is unique to birds and

some reptiles. It can have a folded, fan-like or

conical structure. It has a nutritional function

as well as regulating pressure and

temperature inside the eye.



Retina

Inner eye layer. This layer is the one thatcontains the nerve cells for vision. The retinain birds is much thicker than that of mammals,

which reflects their excellent vision. It contains two types of nerve cellsrods &

cones

In day-active birds such as parrots, thenumber and density of cones is high about300,000 cones per square millimeter.



Ultraviolet vision

Another special feature of avian cone cells is thatthey contain droplets of colored oil, whichfunction as filters to increase the width of thecolor spectrum.

. While humans have rods that are most sensitivein the areas of red, green ,and blue. Birds have 4or 5 different types, which causes them to detectultraviolet light, fluorescent light, in addition to

red, green, and blue light or they are"tetrachromatic" or "pentachromatic"depending on the species.



Vision in the ultraviolet spectrum is important

for e.g. seeing UV reflections off the cuticle of

berries, which indicates if they are ripe or not.

It is also said that UV light plays an important

role in the birds circadian rhythm and

reproduction.



Facts:

Accommodation of the lens:

most day-active birds have about 30-50D

range of accommodation.Sharpness of vision

day-active birds have a much higher density of

cones and a more homogenous distributionon the retina, which leads to a higher

resolution overall.



Detection of movement parrots can see at about 150-200 frames per

second (fps)

And they have a third eyelid called thenictitating membrane. It helps to be able tosee when blinking which prevents it from

drying out during flight, acting like birdygoggles.



Parrots Binocular field

(a) an approach to an object and

(b) manipulation of an object.



(a) a parrot is likely to approach a targetobject with its head pitched downwards, sothat the object is near the point of maximumbinocular width (at 90° elevation) within thebird's field of view, which is thought to be

near the point of highest visual acuity. However, once the object is actually grasped

(b), tactile exploration, using the bill tip organand ygodactyl feet, is likely to dominate visual

exploration, as the parrot can only see justbelow its bill tip. Also the unique shape of thebill obstructs seeing the detail of anythingheld within the bill.



What makes a parrot different from

other bird species?

The parrots visual field is unlike those of anyother bird species. It has a broad frontalbinocular field and a near comprehensive

view around the head. The scientists suggestthat tactile cues that parrots receive fromtheir unique bill-tip organ have led to theabsence of visual coverage of the region

below the bill. Parrots simply feel what theyare doing with an object using a special touchsensitive bill-tip organ, but they cannot seewhat they are doing.

final report visual psyche

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