Melopsittacus undulatusbudgerigar

Geographic Range

Melopsittacus undulatus, commonly known as the budgerigar, is naturally distributed through Australia except for coastal areas in the far east and the far south-west. This species has also been introduced to many areas around the world including S. Africa, Japan, U.S., Puerto Rico, Switzerland, and New Zealand, however, they have only successfully been established in southwest Florida (Juniper, 1998).


Budgerigars occupy a range of semi-arid and sub-humid habitats mainly in the interior of Australia. However, they sometimes can be found in dry grasslands of the southeast. Although mainly restricted to the interior of the continent, there are occasional coastal interruptions in the northeast and in the central south. They seasonally migrate to the north during the winter in order to have a continuing food source (Juniper, 1998).

Physical Description

Budgerigars are small, streamlined parrots that average 18-20 cm in length. They are unlikely to be mistaken for any other parrot because of their small size, pointed wings and tails, and distinct plumage patterns (Juniper, 1998). Most wild budgerigars have a yellow forehead (juveniles have a barred forehead), a yellow and black striped head with purple and black markings on the cheeks, a pointed bill whose tip of the upper mandible extends over the lower mandible, and a yellow throat. Their lesser and median wing coverts are centered black and outlined in yellow. Both their greater coverts and flight feathers are centered black and outlined with green and yellow, but their flight feathers also have a central yellow bar. Their uppertail coverts are bright green and extend to a blue-green tail. Caged species differ greatly in their plumage color and patterns (Phillips, 2000).

There is slight sexual dimorphism. In breeding females, the cere (the skin at the base of the bill, covering the nostrils) is light brown or beige. Otherwise the cere is blue. (Forshaw 1977)

  • Sexual Dimorphism
  • sexes colored or patterned differently
  • male more colorful
  • Average mass
    30 g
    1.06 oz
  • Range length
    18 to 20 cm
    7.09 to 7.87 in
  • Average basal metabolic rate
    0.3035 W


Budgerigars are monogamous and breed in large colonies throughout their range. There has been some record of extra-pair copulations, probably so the female can receive extra help raising the clutch.

Breeding for Budgerigars can occur during any time of the year but most frequently occur with an abundance of seed. Most grass seeding occurs during the winter in northern Australia and during the spring and summer in southern Australia. This means Budgerigars also breed after heavy rains because grass growth is dependent upon water. In fact, any good rain will set off breeding, even when they are in the costly process of molting (Kavanau, 1987).

Budgerigars make their nest in pre-existing cavities that are available in fence posts, logs, and Eucalyptus trees. Several nests can be found on the same tree branch measuring only 3-5 m apart from one another. They fill their nests with decayed wood dust, droppings, and any other soft material available. (Kavanau, 1987)

  • Breeding season
    Breeding for Budgerigars can occur during any time of the year but most frequently occur with an abundance of seed.
  • Average eggs per season
  • Average time to hatching
    18 days
  • Average age at sexual or reproductive maturity (female)
    Sex: female
    180 days
  • Average age at sexual or reproductive maturity (male)
    Sex: male
    180 days

The female chooses the nest site and incubates while the male spends most of the time foraging and feeding all until the chicks are ready to fledge. The parents often have several broods in succession.

  • Parental Investment
  • altricial
  • pre-fertilization
    • provisioning
    • protecting
      • female
  • pre-hatching/birth
    • provisioning
      • female
    • protecting
      • female
  • pre-weaning/fledging
    • provisioning
      • male
    • protecting
      • male
      • female
  • pre-independence
    • provisioning
      • male
    • protecting
      • male
      • female


  • Average lifespan
    Status: captivity
    21 years


Budgerigars aggregate into large flocks and are strongly social. Their grouping allows for greater success in feeding and also helps in protection from predators. There does not seem to be any hierarchy in groups based upon the relatively few battles among individuals, but females are generally more aggressive than males.

Their activity, like most birds, begins just before sunrise with preening, singing, and movement within trees. After sunrise, the birds fly to the foraging area and feed throughout the day. They do not forage during midday or in extremely hot weather, instead they take shelter under shade and remain motionless. At the end of the day, they congregate by calling loudly and flying at high speeds around the trees. They then return to their roosting site just after sunset and remain at rest until the next morning (Kavanau, 1987).

Communication and Perception

Food Habits

Budgerigars are highly successful exploiters of food and water resources whenever available (Kavanau, 1987). They are ground-feeders and thus prefer to take the seeds of grasses and crop plants, particularly spinifex and tall tussock grasses. They first dehull the seed and then swallow it whole or broken. These seeds are extremely energy rich and are equivalent to the caloric content of animal tissue. Therefore, no alternate food source is necessary. Budgerigars are very scheduled in their drinking habits and drink about 5.5% of their body weight daily (Kavanau, 1987). To satisfy this demand, they often locate themselves near water holes. (Kavanau, 1987)

  • Plant Foods
  • seeds, grains, and nuts

Economic Importance for Humans: Positive

Budgerigars are the most widely known pet bird in the world (Phillips, 2000). Their population of about 5,000,000 worldwide has allowed scientists ample opportunity to study them. In fact, more is known of their biology than of any other parrot.

Economic Importance for Humans: Negative

Their ability to consume a large number of seeds when in groups concerns farmers.

Conservation Status

None known.

Other Comments

Budgerigars are the only bird known to use their feet for scratching the sides of the crissum (undertail coverts). According to Kavanau, Budgerigars exist in more color varieties than most other species of bird or animal (Kavanau, 1987). The scattered colors of their plumage are accentuated in ultra-violet light, especially the sides of their cheeks, which may play a part in sexual dimorphism. Check out for an amazing video of Budgerigars hatching.


Kelly Sims (author), University of Michigan-Ann Arbor, Terry Root (editor), University of Michigan-Ann Arbor.



Living in Australia, New Zealand, Tasmania, New Guinea and associated islands.

World Map


living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

World Map


uses sound to communicate


young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.


uses smells or other chemicals to communicate

  1. active during the day, 2. lasting for one day.

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.


forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.


an animal that mainly eats seeds


An animal that eats mainly plants or parts of plants.


referring to animal species that have been transported to and established populations in regions outside of their natural range, usually through human action.


offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).


Having one mate at a time.


having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.


generally wanders from place to place, usually within a well-defined range.


reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.


the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.


reproduction that includes combining the genetic contribution of two individuals, a male and a female


associates with others of its species; forms social groups.


uses touch to communicate

tropical savanna and grassland

A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.


A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.

temperate grassland

A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.


uses sight to communicate

year-round breeding

breeding takes place throughout the year


Forshaw, J. 1977. Parrots of the World. Neptune, NJ: TFH Publications.

Juniper, T., M. Parr. 1998. Parrots: A Guide to the Parrots of the World. Sussex, TN: Pica Press.

Kavanau, J. 1987. Behavior and Evolution. Los Angeles, California: Science Software Systems, Inc..

Phillips, N. August 19, 2000. "Index Page for Pages on Budgerigars with a difference" (On-line). Accessed October 22, 2000 at