Nymphicus hollandicus

Geographic Range

Cockatiels are native to the Australian mainland; they are widely distributed throughout Australia, with denser populations in the southwestern region of the continent. Cockatiels are also found in Tasmania, but are considered to have been introduced to this island accidentally.

• Biogeographic Regions
• australian australian
  • native native

Habitat

Cockatiels are widely distributed through the Australian mainland, tending to prefer inland areas to coastlines. They tend to congregate in areas near bodies of freshwater and prefer generally open areas as opposed to dense forest. Thus, open woodland areas encompassed by waterways in addition to savannas bordering waterholes are optimal areas to find cockatiel flocks. Generally nomadic, cockatiels prefer Acacia seeds to other foods and densely populate areas with Acacia shrubs. (Pizzey and Knight, 1997). Cockatiels follow preditable migratory patterns in southern Australia, where weather patterns are more regular. Here, they move in groups of one hundred to one thousand (Kavanau and Lee, 1987). Cockatiels are presented with large temperature variations in their habitats, from 4.5 degrees Celsius during winter nights to heat exceeding 43 degrees Celsius in the summer (Allen and Allen, 1981). Cockatiels are secondary cavity nesters, preferring large tree hollows when building nests (typically dead eucalypts). Nest sites are usually near water, approximately one to two meters above the ground.

• Habitat Regions
• tropical tropical

• Terrestrial Biomes
• savanna or grassland savanna or grassland

Physical Description

The smallest member of the Cacatuinae subfamily (the cockatoos), with an average weight of 80 g, cockatiels slender and streamlined. Cockatiels are the only type of crested parrot that has a tail which comes to a point. This tapered tail is very long (ca. 15 cm), making up half of their length. In flight, these tail feathers spread out into a wide fan, the elevation angle of which can be adjusted by the bird to control altitude and stability. While long-term artificial selection for mutations in color have resulted in many different color variations in pet cockatiels (from the speckled pearl mutation to the light yellow-white lutino mutation), wild cockatiels of both sexes share similar characteristics in appearance. Males exhibit dark brown to gray plumage, with patches of white bordering areas such as the upper wing when folded. Their cheeks have bright orange circular patterns, bordered by white. Females are also mainly gray, with cheek patches of a drab, burnt-orange shade, which lack a white border. Feathers in these cheek patches are modified to protect the ear and minimize flight turbulence. The underside of the tail feathers tends to be more complex in color variation than the rest of the body, possessing distinctive bars of alternating color. Both males and females have dark brown irises and crests of approximately 5 cm. These crests, composed of several dozen feathers, adorn the top of the head and are used in communication; the angle at which the crest is held is indicative of a bird’s mood. Cockatiel coloration has resulted from natural selection to optimize camouflage while foraging on the ground. Their colorations allows them to be easily overlooked by aerial predators, especially in shady areas. Their beaks, characteristic of all parrots, have curved upper sections that come to a point. The nostrils sit atop the beak at the attachment point of the upper beak to the skull and are round. The bill is dark gray, while legs are blackish gray. Cockatiels exhibit zygodactyly, as do all parrots , they have two toes facing backwards, and two facing forwards.

• Other Physical Features
• endothermic endothermic
• homoiothermic
• bilateral symmetry bilateral symmetry

• Sexual Dimorphism
• sexes colored or patterned differently
• male more colorful

Reproduction

Cockatiels are monogamous and form relationships with a mate early on. These bonds serve for more than reproductive purposes - pairs stay together and remain loyal to one another throughout the entire year. Because cockatiels remain paired throughout the year, they readily proceed to breeding without expending energy to find a suitable mate. Before mating begins, there are several ritualistic behaviors that both sexes exhibit. Vocalization plays an important role in communicating readiness in both sexes; females emit muffled peeps while holding their tail feathers erect to signify readiness, while males are much more aggressive in their vocalizations, whistling unique mating calls referred to as songs. Males accompany these songs with a variety of physical behaviors, including a strut-like walk, holding of the wings erect and away from the body, and rapid beak-pounding to draw attention. One of the behaviors observed in male cockatiels just prior to mating is the observation of the nest cavity, a preselected hollow in which to lay eggs. Males inspect nest cavity for threats before females first enter them, and often males will repeatedly jump in and out of boxes to signify safety.

• Mating System
• monogamous monogamous
• cooperative breeder cooperative breeder

Cockatiel breeding is tied to seasonal changes, the most important being rainfall. Large spring rainfalls assure plentiful food supplies and usually trigger mating events. Interesting field observations to note are the behaviors of cockatiels before large spring rain storms: “[W]hen a thick black rain cloud darkens the sky, cockatiels call excitedly to one another as they fly from perch to perch. The excitement of these events usually elicits a frenzy of sexual display by the males…who search for nestholes accompanied by the hen (Smith, 1978).” As secondary cavity nesters, cockatiels nest in large tree hollows, where pairs typically claim an entire tree. They prefer dead eucalypts approximately 2 meters above the ground and close to a source of freshwater; these snags riddled with cracks are favored as they are less likely to become flooded with water during periods of excess rainfall. Upon obtaining an adequate nest hole and after safety inspections by the male, mating can commence. Once stored in the oviduct, cockatiel spermatozoa are long-lived, allowing egg fertilization up to a month after disposition. Females oviposit as soon as four days after finding a nest hole, and clutch sizes generally average from four to seven eggs, which are laid every other day. Female cockatiels are indeterminate egg-layers, having the ability to replace lost or broken eggs with more. Hence, if nutritional demands are sustained, females can continue to lay eggs until a clutch of appropriate size is established. Eggs are incubated for 17 to 23 days and chicks are independent and leave the nest by five weeks, though sexual maturity is not reached until 13 months in males and 18 months in females.

• Key Reproductive Features
• iteroparous iteroparous
• seasonal breeding seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual sexual
• fertilization fertilization
• oviparous oviparous

Cockatiels have a strong parental drive and both parents share responsibilities in the hatching and raising of chicks. Both male and female chicks have unique roles in incubating eggs; males incubate eggs from early morning to late afternoon, while females incubate throughout the entire night. Males stand outside the nest cavity near the entrance at nightfall. When chicks hatch, both parents participate in allofeeding, the process through which food is passed from one bird to another, but the male mainly carries this role. This feeding process is usually initiated 2 h post-hatch. Cockatiels rarely abandon chicks; in captive studies many would not leave the nest box unless physically removed by researchers. As many duties are shared by both parents, parental compatibility is essential in cockatiels; a study by Spoon and Milliam (2006) suggests that this compatibility correlates to many aspects of reproductive success, including clutch size and number of chicks raised to independence.

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

Lifespan/Longevity

Wild cockatiels have a lifespan of 10 to 14 years. Those in captivity can live much longer; extensive research in cockatiel nutrition and metabolic requirements have allowed for diet optimization to achieve optimum health. Captive cockatiels can live for up to 25 years, with the oldest on record reaching an incredible 36 years old. Diet and environmental factors play essential roles in cockatiel lifespan.

Behavior

Cockatiels are exceptionally social birds, establishing pair bonds early on and usually feeding and moving together in groups of several birds to larger flocks of up to several thousand. Migratory patterns are region-specific; northern Australia’s wetter climates have more nomadic cockatiel populations, continually relocating to fresh water and food, while the weather patterns of southern Australia offer more predictability, thus southern cockatiels seasonally migrate in groups. Cockatiels are timid by nature and exhibit several preferences in nesting habits, foraging habits, and more. With no prevalent natural defense mechanisms, cockatiels always choose flight when a threat is perceived; they are able to attain speeds in excess of 40 miles per hour in the air. Cockatiel feathers serve many important physiological purposes and often feather presentation in cockatiels is indicative of mood; cockatiels contract feathers to appear very thin when frightened, and puff them out when content. Feathers serve as the means through which flight is achieved, but also provide insulation to conserve body heat; cockatiels must maintain internal body temperatures in excess of 100 degrees Fahrenheit (38 degrees Celsius). Outer feathers are waterproofed. This is achieved through preening, which can constitute a substantial portion of a cocktiel’s daily routine. Cockatiels waterproof their outer feathers by making direct beak contact with their uropygials or sebaceous glands, which secrete an oily substance that they then manually coat their feathers with. Similar to other members of the Cacatuinae subfamily, cockatiels have a powder down composed of keratin. This powder down serves to further waterproof feathers, but is removed in excess through preening. Large clouds of dust can be seen coming from perching cockatiels as they shake themselves after a preening session. A final important aspect of preening comes in the contents of oil secreted from the uropygial. This oil contains vitamin D precursors that coat feathers; these precursors when exposed to sunlight activate to produce vitamin D, which is essential for calcium absorption. Cockatiels ingest this synthesized vitamin D while preening.

• Key Behaviors
• arboreal arboreal
• scansorial
• flies
• diurnal diurnal
• motile motile
• nomadic nomadic
• migratory migratory
• social social

Home Range

Cockatiel territories can span several miles from their nest. As they generally nest close to an available freshwater source, they don’t typically have to travel far to hydrate themselves. However, groups of cockatiels can venture great distances from their nests during normal foraging on the ground for seeds. These distances can be achieved relatively quickly, thanks to their high flight speeds.

Communication and Perception

Cockatiels are unlike some larger species of parrots in that they cannot accurately imitate the human voice, but have the ability to mimic melodies and can sing. Cockatiels have a range of distinctive variations used to communicate moods. High-pitched chirps can be indicative of stress and, by the pitch and duration of the cry, the magnitude of the stressor can in some cases be determined. For example, cries of a lower pitch can be indicative of a mild stressor, while higher pitched cries are accompanied by flight. This indicates that a threat is severe enough to cause immediate evasion. Cockatiels can communicate over relatively large distances, as they are shrill and very loud. Other forms of vocal communication are male songs, which are prolonged calls occurring during mating periods to indicate availability and attract females. Cockatiels also express mood visually through the use of their crests. The crest is held vertically erect when the bird is startled or is alert. When content, it is generally held at roughly a 45-degree angle to the head. When agitated or threatened, the crest is held flat against the head. During flight, the crest is also laid flat against the skull, reducing wind drag. Another notable behavior is the spreading of the wings both upwards and outwards while at rest. This is typically seen in reproductive courtships by both sexes and is often used as a visual method to impress another bird.

• Communication Channels
• visual visual

• Other Communication Modes
• mimicry mimicry

• Perception Channels
• visual visual
• tactile tactile
• acoustic acoustic
• chemical chemical

Food Habits

Cockatiels are almost exclusively ground foragers. They are zygodactylous, their long toes not only serve to wrap around perches, but also extend outward to make extremely large, stable feet for walking on the ground. While cockatiels can feed on a variety of plant and animal matter, their sharp curved beaks are adapted to maximize efficiency in shucking and consuming seeds, their food of choice. Either in pairs, small groups of 6 to 8 birds, or larger flocks of several hundred birds, cockatiels search open areas for sun-dried seeds from grasses, shrubs, and trees. Cockatiels use their tongues to rotate seeds as they use their upper beak to remove shells; they can remove a shell and consume a seed in only a few seconds. Cockatiels also remove seeds directly from branches. Cockatiels obtain water primarily from freshwater pools such as water-holes. Vulnerable to predation on the ground, they drink rapidly, usually only taking one to two sips of water, then extending their necks upwards to swallow and survey their surroundings. Cockatiels utilize metabolic water production, and can go for long amounts of time without drinking. Versatile in their feeding behavior, cockatiels can also consume softer foods, such as fruits and berries. They have also been observed to eat small ground-dwelling insects. Cockatiels remain silent during foraging.

• Primary Diet
• herbivore herbivore
  • granivore granivore

• Animal Foods
• insects

• Plant Foods
• seeds, grains, and nuts
• fruit

Predation

Australian birds of prey are the primary predators of cockatiels. Cockatiels are mostly preyed upon from above while feeding by raptors. They are camouflaged to blend in with the ground. Other than their coloration, cockatiels have no natural defenses to predators other than their high-speed flight. Thus, cockatiels always respond to threats by aerial evasion. They also use loud, shrill vocalizations to communicate threats among each other and stay in large flocks, where many eyes can look for predators. Cockatiels can also in extreme circumstances deliver a powerful bite from their sharp beaks and well-developed jaw muscles, which can easily pierce the skin. Cockatiels bite as a last resort defense mechanism, which can be observed in nesting cockatiels confronted with an invasive predator to the nestbox.

• Anti-predator Adaptations
• aposematic aposematic
• cryptic cryptic

Ecosystem Roles

Although they prefer sun-dried seeds, cockatiels can serve the role of seed-dispersers in their ecosystems when they choose to consume fresh seeds, as they are very messy eaters and scatter seeds and shells as far as four to five feet away from themselves when they eat. They can also disperse the seeds of the fruits they consume.

Cockatiels are also susceptible to bacterial infection, particularly in the liver, and in such cases harbor bacteria such as Giardia lamblia and Cryptosporidium galli , which are associated with weight loss, abnormal droppings, and mortality.

• Ecosystem Impact
• disperses seeds

Economic Importance for Humans: Positive

Cockatiels are popular pets, the second most popular bird after budgerigars. Through selective breeding, dozens of color mutations have been achieved; perhaps the most extreme of these is the lutino variation, in which the cockatiel is completely white or light yellow, with only its bright orange cheek patches accentuating this uniform color. Cockatiels bred selectively can sell for high prices. Societies such as the National Cockatiel Society host regular shows and exhibitions in which cockatiel breeders can showcase their birds and compete for prizes. Many students also benefit from cockatiels by conducting research in university settings. The Psittacine Research Group in California is one group that has an established cockatiel colony devoted to research. This laboratory has provided students with research experience, as well as valuable data to the scientific community concerning cockatiel nutrition and behavior.

• Positive Impacts
• pet trade pet trade
• research and education

Economic Importance for Humans: Negative

Cockatiels can be regarded as pests to agricultural industries in Australia, where flocks of several thousand have been known to raid crop fields, particularly fields of sorghum, millet, wheat, and sunflowers. There have been open seasons on cockatiels in Queensland, Australia. They are generally protected by law and are sometimes dealt with by the use of pesticides to deter them from fields.

• Negative Impacts
• crop pest

Conservation Status

Cockatiels have a very large range and densely populate the Australian mainland. The exact population has never been quantified for this reason and they are not considered threatened currently.

Other Comments

As pets, cockatiels are extremely loyal to their owners once they have established a bond, which is similar to the pair-bonds between wild cockatiels. Cockatiels are also favored to other birds partially because of their social rituals with one another in the wild; pair bonds show affection by grooming each other’s head, so pet cockatiels enjoy being stroked on the head, often lowering their heads to signify their desire to be petted. Male cockatiels can also mimic melodies, further increasing their popularity.

Additional Links

Encyclopedia of Life

Contributors

Brandon Newmyer (author), Radford University, Karen Powers (editor), Radford University, Tanya Dewey (editor), University of Michigan-Ann Arbor.

References

Allen, G., C. Allen. 1981. Cockatiel Handbook . Neptune, New Jersey: TFH Publishing Co.

Antunes, R., D. Simoes, A. Nakamura, M. Meireles. 2008. Natural infection with Cryptosporidium galli in Canaries (Serinus canaria), in a Cockatiel (Nymphicus hollandicus) and in Lesser Seed-Finches (Oryzoborus angolensis) from Brazil. Avian Diseases , 52: 702-705.

Blakers, M., S. Davies, P. Reilly. 1984. The Atlas of Australian Birds . Beaverton, OH: Melbourn University Press.

Cayley, N. 1931. What bird is that? A guide to the birds of Australia. . Sydney, Australia: Angus and Robertson LTD.

Foreshaw, J., W. Cooper. 2002. Australian Parrots 3rd edition . Melbourne, Lansdowne: Avi-Trader Publishing.

Kavanau, , Lee. 1987. Behavior and evolution: lovebirds, cockatiels, and budgerigars. . Los Angeles, California: Science Software Systems.

Martin, S., R. Millam. 1995. Nest box selection by floor laying and reproductively naive captive cockatiels. Applied Animal Science , 43: 95-109.

McCaffery, E. 2009. "Cockatiel Cottage" (On-line). Accessed March 15, 2010 at www.cockatielcottage.net .

Millam, J., B. Zhang, E. El Halawani. 1996. Egg production of cockatiels (Nymphicus hollandicus) is influenced by number of eggs in nest after incubation begins. General and Comparative Endocrinology , 101: 205-210.

Pizzey, G., F. Knight. 1997. Field Guide to the Birds of Australia . Sydney, Australia: Angus and Robertson.

Roudybush, T., C. Grau. 1991. Cockatiel (Nymphicus hollandicus) Nutrition. The Journal of Nutrition , 121: 206.

Smith, G. 1978. Encyclopedia of Cockatiels . Neptune, New Jersey: TFS Publishing.

Spoon, T., J. Milliam. 2006. The importance of mate behavioral compatibility in parenting and reproductive success by cockatiels, Nymphicus hollandicus. Animal Physiology , 71: 315-326.