Description:
There is a very wide variety of parakeets! They consist of about 120 species with many sub-species. The parakeet genera are found in various parrot sub-families.
Parakeets are small to medium sized parrots generally with slender bodies and long, tapered tail feathers. They vary in size from about 7" up to 18" (18-45 cm) in length and their feathers are brilliantly colored.
They have a hooked upper bill that they use to climb, hold things, or to dig. They also use their beak to chew, break seeds, and peel fruit. Most parakeets have an unfeathered cere at the top of their beak that surrounds their nostrils. The coloration of the cere on some parakeets, such as the Budgerigar, is different for the male and the female making it easy to sex them.
Parakeets are fairly intelligent birds. Each species has its own set of calls with some birds being quite adept at mimicking sounds they hear. Some will repeat words, phrases and even whistle!
The average life span of parakeets, though longer in captivity than in the wild, is unknown on most species. It is known that some of the smaller parakeets such as the Budgerigars, the Bourke's Parakeet, and the Elegant Parakeet may reach about 10 years, while some of the larger parakeets such as the Ringneck Parakeet and the Regent Parakeet may reach up to 25 years.

Distribution:
Parakeets live in many diverse habitats and are found throughout Australia, Asia, tropical and subtropic regions of Africa, Central and South America.
Australia has over 30 species of parakeet including: Budgerigar, Cockatiel (described in the Cockatiel section), Bourke's Parakeet, Princess of Wales, Red-rumped Parakeet, Stanley Parakeet, Mulga Parakeet, Scarlet-chested Parakeet, Red-winged Parakeet,Turquoise Parakeet, Blue-winged Parakeet, Red-capped Parakeet, Elegant Parakeet, Superb Parakeet, Regent Parakeet, Mallee Ringneck Parakeet, Port Lincoln Parakeet, Australian King Parakeet, and five of the six species of the Rosellas including the Pennant's Parakeet (Crimson Rosella), Golden-manteled Rosella (Eastern Rosella), and the Pale-headed Rosella, .
Asian parakeets include the Indian Ringneck Parakeet, Mustached Parakeet, Rose-ringed Parakeet, and the Plum-headed Parakeet.
New Zealand has 2 species including the Yellow-fronted Parakeet.
Central and South American parakeets (whose colorings are not quite as intense as the Australian parakeets) include: the Quaker or Monk Parakeet, Barred Parakeet, Canary-winged Parakeet, Grey-cheeked Parakeet, Orange-chinned Parakeet, Tui Parakeet, and conures such as the Mitred Conure and the Nanday Conure (see them under the Conure section).

Care and feeding:
Fresh food and water must be provided daily. In the wild, parakeets feed on seeds, fruits, nuts, berries, blossoms, leaf buds, and some enjoy nectar, insects, spray millet and grains. A parakeet's diet consists of a good seed mixture supplemented with sprouted seed, various fruits, green foods, millet spray (for small parakeets), and for some, occasional mealworms are generally regarded suitable. Different seed mixes for parakeets are available, depending on its size and the strength of its bill.
There are parakeet seed mixes for birds the size of a budgerigar, cockatiel mixes for birds a bit bigger, and conure/small parrot mixes for the larger parakeets. A single small parakeet will eat about two tablespoons of seed a day and a half a cup of fruits and vegetables. A larger parakeet will eat about four tablespoons of seed a day and a cup of fruits and vegetables.
Supplements are very important and can be put in an extra dish and rotated for variety. Some of the supplemental fruits include apples, grapes, bananas, pears, cherries, mangos, oranges, papaya, melons, peaches, and berries. Many garden vegetables that are good include spinach, watercress, field lettuce, poppy, chickweed, dandelions, carrots, corn on the cob, peas, zucchini, green peppers, endive, and sweet potatoes. Additional proteins can be offered on rare occasions and definitely when your parakeets are brooding. Some proteins are cottage cheese, hard boiled eggs, peanuts, monkey chow, and even dog food.
Note: Do not feed avocado as it is toxic to birds! Other foods that are indigestible to birds are raw and green potatoes, all the cabbage family, grapefruit, lemons, plumbs, rhubarb, and dried fruits that have been treated with sulphur dioxide.
Vitamins can be added to the drinking water or the food about 2 or 3 times a week, offer sparingly or not at all if they are being offered a wide range of other supplements. A cuttlebone or mineral block is important for their beak. Bird sand or gravel and oyster shell provides important minerals and can be offered in a separate dish.
The personal hygiene of your parakeet (for those species that like it!) can include a bath or shower two or three times a week to help keep it's plumage in good shape. Different species prefer different kinds of bathes and some do not want a bath at all. Bathing can be accomplished with either a flat earthenware dish that your bird can step into and use it's beak to throw water on itself, or by spraying your bird with a light mist of lukewarm water. Use either a hand held shower sprayer or a hose with a fine spray head.
The wings should be kept trim if you want to discourage flight and to prevent the loss of your pet through an open window or door. The beak needs to be trimmed if it becomes overgrown or deformed. There are many mineral blocks, lava blocks, and other beak grooming items available at your pet store to help your bird keep it's beak in shape. A variety of concrete type perches are also available to help keep the nails trim, but they should be trimmed if they become overgrown. Bird nail trimmers and styptic powder to stop the bleeding are also available at pet shops.

Housing:
Parakeets in the wild are fast, long distance flyers and need a home that provides them with room to fly and exercise. As a general rule, the larger the cage, the happier your parakeet. Parakeets kept in a cage need to be let out for exercise daily. The parakeet cage should be large enough so that the bird's head does not touch the top, it's tail does not touch the bottom, and it has enough room for unrestricted movements. A cage for a pair of small parakeets should be at least 39"x20"x32" (100x50x80 cm). A cage for a pair of larger parakeets should be at least 59"x32"x59" (150x80x150 cm) and bigger for the even larger species. These sizes will provide room for lots of movement as well as horizontal exercise and vertical climbing. This also provides space for perches, food dishes and a variety of playthings.
Place the cage where it will be away from harmful fumes and drafts. Keep the cage well ventilated and have good lighting. Most parakeets need a humidity level of 60 to 70% and 12 hours of daylight.To provide you pet with a sense of security, you can cover the cage at night.
You will need dishes for food, water, treats, and grit. Also provide two perches starting at 1/2" (12 mm) for the smallest parakeets, with larger diameters for larger birds. Perches can be round or square as well as various sized fruit tree branches. Natural perches from willow, poplar and fruit trees are good for the bird's feet and for it's beak. The gnawing it will do on the perches will also alleviate your pet's boredom. Place one perch up high for roosting and one low by the food, water, and grit dishes.

Maintenance:
The basic cage care includes daily cleaning of the water and food dishes. Weekly you should wash all the perches and dirty toys, and the floor should be washed about every other week. A total hosing down and disinfecting of an aviary should be done yearly, replacing anything that needs to be freshened, such as old dishes, toys and perches.

Social Behaviors:
Parakeets are very social with good personalities. They are friendly to people and like lots of attention and handling. Both males and females make equally good pets.
Parakeets are flock oriented birds, which contributes to them needing a full-time companion. It is best if you can keep them in pairs or in small flocks. Pairs of breeders should be housed separately, however, as many species become aggressive during this time.

Handling/Training:
Parakeets become accustom to their new environment fairly rapidly. Generally though, you should give a new arrival a few days to get use to you, your voice and it's cage before trying to handle it. A hand fed baby will not need much taming and can often be handled right away, as it is use to human attention. To be able to handle and train your parakeet depends first on trust, so go slowly and be consistent.
Parakeets are generally most receptive to training in the evening and each session is best if limited to under 20 minutes with about an hours rest in between. Your first goal is to get the parakeet to accept a treat from you, which will lead to it allowing you to gently scratch it's head. Then you can begin to work on getting your parakeet to step up on your hand.
Depending on the tameness of the bird, these two steps can be instantaneous as in a hand fed baby or take several weeks or longer for an untamed bird. Remember that taming and training a bird takes patience, never 'punish' your parakeet! This only serves to destroy the trust you've spent so much time building.
Once your parakeet has gotten over it's shyness, then you can work on speech training. Repetition and frequency are the keys here. Almost every parakeet can learn at least a few words, although they are not generally as vocal as African Greys or the Amazons.

Activities:
Exercise and play are important activities for the physical well being and psychological health of your parakeet. Being designed for long distance flying, parakeets need to fly! If you keep your parakeet in a cage, you should let it out to fly a couple of hours each day.
They also love to climb and chew! Natural perches and fresh twigs from willow, elder, poplar, chestnut, linden, hawthorn, and fruit trees work well for this, as does knotted hemp rope. Provide your parakeet with lots of activities! Other playthings they will enjoy are climbing ropes, wooden ladders, chains, bells, parrot swings, and wooden or other bird safe toys.