The budgerigar (/ˈbʌdʒərɪˌɡɑːr/; Melopsittacus undulatus) is a long-tailed, seed-eating parrot usually nicknamed the budgie, or in American English, the parakeet. Budgies are the only species in the genus Melopsittacus. Naturally, the species is green and yellow with black, scalloped markings on the nape, back, and wings. Budgies are bred in captivity with colouring of blues, whites, yellows, greys, and even with small crests. Juveniles and chicks are monomorphic, while adults are told apart by their cere colouring, and their behaviour.

The origin of the budgie's name is unclear. First recorded in 1805, budgerigars are popular pets around the world due to their small size, low cost, and ability to mimic human speech. They are the third most popular pet in the world, after the domesticated dog and cat.[3] Budgies are nomadic flock parakeets that have been bred in captivity since the 19th century. In both captivity and the wild, budgerigars breed opportunistically and in pairs.

It is found wild throughout the drier parts of Australia, where it has survived harsh inland conditions for over five million years. Its success can be attributed to a nomadic lifestyle and its ability to breed while on the move.[4] The budgerigar is closely related to lories and the fig parrots.The budgerigar has co-existed with Indigenous Australians for 50–70,000 years. Several possible origins for its name have been proposed. First, it may be a mispronunciation or alteration of the Gamilaraay word gidjirrigaa (Aboriginal pronunciation: [ɡ̊iɟiriɡaː])[9][10] or gijirragaa from the Yuwaalaraay.[11] Second is a modification budgery or boojery (Australian English slang for "good") and gar ("cockatoo").[12] Alternative spellings include budgerygah and betcherrygah,[13] the latter used by indigenous people of the Liverpool Plains in New South Wales.[14] While many references mention "good" as part of the meaning, and a few specify "good bird", it is quite possible that reports by those local to the region are more accurate in specifying the direct translation as "good food".[15] However, reports that this could also translate as "tasty treat", implying they were eaten by the aborigines, are likely to be apocryphal. The name likely derived from the species' migratory nature. With seasonal changes that left the plains barren, the budgerigar would move towards residual water that still produced the seeds they sought. By following the birds, the aborigines could locate water and also other game or food plants – thus, leading to "good food".

The budgerigar was first described by George Shaw in 1805, and given its current binomial name by John Gould in 1840. The genus name Melopsittacus, from Ancient Greek, means "melodious parrot".[16] The species name undulatus is Latin for "undulated" or "wave-patterned".[17]

Alternative names for the budgerigar include the shell parrot, the warbling grass parakeet, the canary parrot, the zebra parrot, the flight bird, the scallop parrot. Alth