Conservation status Least concern
Budgerigar hen of approximately natural colouration
The Budgerigar (Melopsittacus undulatus, nicknamed budgie), the only species in the Australian genus Melopsittacus, is a small parrot belonging to the tribe of the broad-tailed parrots (Platycercini); these are sometimes considered a subfamily (Platycercinae), which may be correct, in which the budgerigar is then placed as a separate tribe (Melopsittini), which is almost certainly erroneous. Though budgerigars are often called parakeets, especially in American English, this term refers to any of a number of small parrots with long flat tails. The budgerigar is found throughout the drier parts of Australia and has survived in the inlands of that continent for over 5 million years.
At least two possible origins for the English name budgerigar have been proposed:
- A compound of budgery, "good" and gar "cockatoo" in some Australian Aboriginal languages. This is supported by the Oxford English Dictionary. The word budgery itself, also spelt boojery, was formerly in use in Australian English slang meaning "good".
- An alteration of Gamilaraay gidjirrigaa (IPA: /ɡiɟiriɡaː/), possibly influenced by the slang word budgery mentioned above. This is supported by the American Heritage Dictionary.
The genus name Melopsittacus comes from Greek and means "melodius parrot". The species name undulatus is Latin for "undulated" or "wave-patterned".
Budgerigars are about 18 cm long and weigh 30-40 grams. Wild budgerigars have green underparts and rumps, while the upperparts are barred with black and yellow. The forehead and face is yellow in adults, and barred black with yellow in young till they change into their adult plumage at 3-4 months of age. Each cheek has a small dark purple patch and a series of black spots across the throat. The tail is greenish blue or purple; outside tail feathers have a central yellow band. Their wings have greenish-black flight feathers and black coverts with yellow fringes. Bill olive grey and legs greyish blue, with zygodactyl toes. Wild budgerigars are noticeably smaller than those in captivity. These parrots have been bred in many other colours in captivity, such as white, blue, and even purple, although they are mostly found in pet stores in blue, green and seldomly white.
The colour of the cere (the area containing the nostrils) differs between the sexes; royal blue in males, pale-brown to white(non-breeding) or brown (breeding) in females and pink in immatures of both genders (usually of a more even purplish-pink colour in young males). Young females can often be identified by a subtle chalky whiteness that starts around the cere nostril holes. Males that are albinos, lutinos or recessive pieds usually retain the immature purplish-pink cere color their entire life. 
There are presently at least 32 primary mutations in the Budgerigar Parakeet enabling hundreds of possible secondary mutations (stable combined primary mutations) & colour varieties (unstable combined mutations)
Of which the australian-recessive-grey-factor, the BrownWings, the DarkWings, the english-recessive-grey-factor, the Faded the english-recessive-grey-factor, the NSL-Ino & the SaddleBack mutations are either highly uncommon, extremelly rare &/or presumed 'extinct' of visual specimens.
Each of those 32 primary mutations belonging to either one of the 4 basic groups of mutations classified in Parrot species genetics. Namely ;
Albinism : where eumelanin is reduced in ALL body tissues & structures deviding into 2 sub-groups ; Complete-Albinism & Incomplete aka Partial Albinism,
Dilutism : where eumelanin is always +/- incompletely (never completely) reduced virtually only in feathering,
Leucism : where eumelanin is reduced virtually only in feathering and devides into 2 sub-groups ; Total-Leucism & Local-Leucism,
Melanism : where eumelanin is +/- increased virtually only in feathering.
Each of those 32 primary mutations inherit either ;
autosomal-Co-Dominant (A-Co-D), autosomal-Complete-Dominant (A-C-D), autosomal-Incomplete-Dominant (A-I-D), autosomal-recessive (A-R), autosomal-Poly-Genic (A-P-G) Sex-Linked-recessive (S-L)
It must be noted that : the word autosomal is often replaced as a synonym by the NSL acronym standing for Non-Sex-Linked.
Here's a listing of the Budgerigar aka Budgie Parakeet's 32 primary mutations genetic identities, followed by their common names in parenthesis, followed by their according allele &/or Locus symbols & ending with their genetic inheritance ;
Blue Loci (plural of Locus) :
Dark-Factor : D-Locus : A-Co-D with regards to only other Blue Loci alleles &/or always otherwise A-I-D
Blue : bl*bl : A-Co-D with regards to only other Blue Loci alleles &/or always otherwise A-R
BlueII : blII-Locus : A-Co-D with regards to only other Blue Loci alleles &/or always otherwise A-R
YellowFacedBlue : blII*yf : A-Co-D with regards to only other Blue Loci alleles &/or always otherwise A-R
GoldenFacedBlue : blII*gf : A-Co-D with regards to only other Blue Loci alleles &/or always otherwise A-R
Structural mutations :
Crest-Factor : Cr-Locus : A-P-G
Dark-Factor : D-Locus : A-I-D
Grey-Factor (Dominant-Grey-Factor) : G-Locus : A-C-D
grey-factor (english-recessive-Grey-Factor) : g-Locus : A-R
grey-factor (australian-recessive-Grey-Factor) : ag-Locus : A-R
Violet-Factor : V-Locus : A-I-D
Dilutistic mutations :
dil-Locus (Dilute Locus) multiple-allelic-series :
Suffused (Dilute) : dil*dil : A-Co-D with regards to only other dil-Locus alleles &/or always otherwise A-R
ClearWings : dil*cw : A-Co-D with regards to only other dil-Locus alleles &/or always otherwise A-R
GreyWings : dil*gw : A-Co-D with regards to only other dil-Locus alleles &/or always otherwise A-R
Local-Leucistic (Pied) mutations :
ADM (Anti-DiMorphic) Pied (danish-pied, recessive-pied, harlequin) : s-Locus : A-R
Piebald (Australian-Pied) : Pb-Locus : A-C-D
Pied (Continental_Dutch-Pied & Clear-Flighted_Dutch-Pied) : Pi-Locus : A-C-D
Total-Leucistic (Clear) mutations :
Spangle-Factor : Sp-Locus : I-D
Dark-Eyed-Clear : dil*cw / dil*gw : is not a genuine primary mutation but a mutation variety produced by the visual combination of ADM-Pied & either Dutch-Pied varieties : A-Co-D
Albinistic mutations :
NSL-Albinism (recessive-albinism) : a-Locus : multiple-allelic-series :
NSL-Ino (recessive-Ino) : a*a : A-R
Bronze_Fallow (german_Fallow) : a*bz : A-Co-D with regards to only other a-Locus alleles &/or always otherwise A-R *This mutation more precisely belongs in the Incomplete-Albinistic mutations but it was necessary to display it's relationship with the a-Locus*
Brown or BrownWings (sepia) : b-Locus : presumed A-Co-D with regards to only other a-Locus alleles &/or always otherwise A-R *This mutation more precisely belongs in the Incomplete-Albinistic mutations but it was necessary to display it's relationship with the a-Locus*
Cinnamon (CinnamonWings) : cin-Locus : S-L-R
Dun_Fallow aka Grey-Brown_Fallow (english_Fallow) : df-Locus : A-R
Faded : fd-Locus : A-R
possible Beige_Fallow aka Pale-Brown_Fallow (australian_Fallow) : pf-Locus : A-R
possible Plum-Eyed_Fallow (scotish_Fallow) : pl-Locus : A-R
SL-Albinism : ino-Locus : multiple-allelic-series :
SL-Ino : ino-Locus : S-L-R
SL-ClearBody : ino*cl : SL-Co-D with regards to only other ino-Locus alleles &/or always otherwise S-L-R
BlackFace : bf-Locus : A-R
Other mutations :
DarkWings : dw-Locus : A-I-D
Dominant-ClearBody : Cl-Locus : A-C-D
Opaline : op-Locus : S-L-R
SaddleBack : sb-Locus : A-R
Slate : sl-Locus : S-L-R
Habitat and behaviour
Budgerigars are nomadic birds found in open habitats, primarily in Australian scrubland, open woodland and grassland. The birds are normally found in small flocks, but can form very large flocks under favourable conditions. The species is extremely nomadic and the movement of the flocks is tied to the availability of food and water. Drought can drive flocks into more wooded habitat or coastal areas. They feed on the seeds of spinifex, grass weeds, and sometimes ripening wheat. .
Feral birds are found in the St Petersburg, Florida area in the United States, but are much less common than they were back in the early 1980's. Colder than normal winter temperatures in some years and increased competition from European Starlings are the main reasons for the declining population.
Breeding takes generally place between June and September in the North and between August and January in the South but they are opportunistic breeders responding to the rains when grass seeds become most abundant. Populations in some areas have increased as a result of increased water availability at farms. The nest is in a hole in a tree, fence post or even a log laying on the ground; the 4-6 eggs are incubated for 17-19 days, with the young fledging about 30 days after hatching.
Both male and female budgerigars sing and can learn to mimic sounds, although both singing and mimicry are more pronounced in males.
Budgerigars in captivity
The budgerigar is one of the few parrots to be domesticated as a pet. Believed to be the most common pet parrot in the world, it has been bred in captivity since the 1850s. Breeders have worked over the decades to produce a wide range of colour and feather mutations, such as yellow, blue, white, violet, olive, albino and lutino (yellow), clearwing and spangled. Feather mutations can produce crests or overly long shaggy feathers known as "feather dusters".
Modern show budgerigars, also called English budgerigars, are larger than their wild cousins, with puffy head feathers, giving them an exaggerated look. The eyes and beak can be almost totally obscured by feathers. Such birds are reported to be more prone to genetic mutations because of inbreeding. Most budgerigars in the pet trade are not of the show variety and are similar in size and body conformation to wild budgerigars.
Budgerigars can be taught to speak, whistle tunes, and play with humans. They are intelligent and social animals and enjoy the stimulation of toys and interaction with humans as well as with other budgerigars. A common behaviour is the chewing of material such as wood, especially for female budgerigars.
In captivity, budgerigars live an average of five to eight years, but are reported to occasionally live to 15 if well cared for . The life span depends on the budgerigar's breed (show budgerigars typically do not live as long as the common budgerigars) and the individual bird's health, which is influenced by exercise and diet.
Although wild budgerigars eat grass seeds almost exclusively, avian veterinarians recommend supplementation with foods such as fresh fruits and vegetables, sprouted seeds, pasta, whole wheat bread and other healthy human foods, as well as pellets formulated for small parrots. Adding these foods provides additional nutrients and can prevent obesity and lipomas, as can substituting millet, which is relatively low in fat, for seeds mixes. Budgerigars do not always adapt readily to dietary additions, however. Chocolate and avocado are recognized as potential toxins. Plums, lemons, limes, and members of the cabbage family are bad for them as well. Recommended fruits and vegetables are apples, oranges, bananas, strawberries, carrots, unsprayed lettuces, parsley, peaches and spinach.
"Context speaking" budgerigars
In 2001, budgie owner Ryan B. Reynolds of Ontario, Canada received much publicity due to his release to the press of certain recordings of his talking budgie, Victor. In these recordings, Victor performed what appeared to be "speaking in context". To the layperson, the recordings appeared to audibly demonstrate that Victor was able to use his 1000+ word vocabulary to express coherent lines of thought, meaning and reasoning. Despite the widespread TV, newspaper and radio publicity the recordings received in 2001, the recordings have yet to be scientifically analysed, proven, (or disproven).
A budgerigar named Puck holds the world record for the largest vocabulary of any bird, at 1,728 words. 
- ^ BirdLife International (2004). Melopsittacus undulatus. 2006 IUCN Red List of Threatened Species. IUCN 2006. Retrieved on 11 May 2006. Database entry includes justification for why this species is of least concern
- ^ Online etymology dictionary
- ^ A Reference Dictionary of Gamilaraay
- ^ a b c d e f Forshaw, Joseph Michael, William T. Cooper (1973 & 1981). Parrots of the World, 1st and 2nd. ISBN 0-87666-959-3.
- ^ Birds Online - How to tell the sex of a budgie. Retrieved on 25 April 2006.
- ^ a b The Wild Budgerigar (article). Retrieved on 25 April 2006.
- ^ Birds Online - Life span of a budgie. Retrieved on 26 December 2005.
- ^ Margaret A. Wissman, D.V.M., D.A.B.V.P.. Medical Conditions and Diseases of the Budgerigar and Cockatiel (article). ExoticPetVet.Net. Retrieved on 26 April 2006.
- ^ Elvira Cordileone (2006). Are Birds Trying to Tell Us Things? (article). Toronto Star. Retrieved on 7 May 2006. publication date: 23 Mar. 2006