Cockatoo
belongs to the bird family “Cacatuidae” and the only family from the family group “Cacatuoidea”.
It has 21 species in the family. Together with “Psittacoidea” (the true
parrots) and “Strigopoidea” (the largest New Zealand parrots), they make and structure
the order “Psittaciformes”. The family has a mostly Australasian distribution, reaching
from the Philippines and eastern Indonesian islands to New Guinea, Solomon Islands,
and Australia.
Size and Weight
Cockatoos
are normally medium-to-large, solid, and sturdy sized parrots which range from 30
to 60 cm (12 to 24 inches) long. They are weighing about 0.66 to 2.65 lb (300
to 1200 gram) in weight. However, one breed of Cockatiel is significantly
smaller and thinner than other breeds. This breed is 32 cm (13 inches) long in
size (including long-pointed tail feathers) and weighing about 2.8 to 3.5 oz (80
to 100 gram) in weight.
Cockatoo Appearance
Cockatoos
are familiar with the attractive crests and curved beaks. Their plumage is usually
less interesting than other parrots. Normally they are bigger than other parrot
species but the Cockatiel (the smallest Cockatoos), is a small bird.
Cockatoos
are common birds in aviculture, but their requirements are hard to meet, whereas, the cockatiel is the easiest Cockatoo species to uphold and kept in imprisonment. The
white-Cockatoos are usually seen in captivity than the black-Cockatoos. The unlawful trade in wild-caught birds causes a decrease of some “Cockatoo” species in the
wild.
Vocalization
The
Cockatoos are very vocal as they can make a loud and harsh call. They perform
various functions comprising letting individuals identify one another, warning
others of predators, demonstrating different dispositions, and maintaining the unity
of the flock for defending their nests. Carnaby's Black Cockatoo can make
more than 15 different calls. Some Cockatoos such as the Gang-Gang, are moderately
silent birds but do have weaker growling calls while feeding. Cockatoo parrots
also make a specific hissing sound when vulnerable.
Distribution and Habitat
The
Cockatoos have a very limited variety than that of “True Parrots”. They are
normally found in Australasia, Indonesia, and the Philippines. Out of 21 species,
11 exists in the wild only in Australia whereas 7 species are found only in
the islands of Philippines, Indonesia, Papua New Guinea, and Solomon. The
remaining 3 species are found in New Guinea and Australia.
Some
species of Cockatoos have extensive distributions, with the galah, for instance,
most are found in Australia, while other breeds have small distributions, for
example, the Baudin's Black Cockatoos of Western Australia or to the minor island-group
like Tanimbar Corella, which is constrained to Tanimbar Islands of Indonesia.
Some Cockatoos have been familiarized unintentionally to the zones outside
their natural range including New Zealand, Singapore, and Palau, whereas, two
Australian Corella breeds have also been familiarized to the regions of the continent
where they are not innate.
The
Cockatoos live in various kinds of habitats from forests in Subalpine areas to Mangroves.
Though, no breed is seen in all the habitats. The most common breeds (galah and
cockatiel) are open-country experts that feed on grass-seeds. They are frequently
extremely moveable fast flyers and are itinerant. The flocks of these parrots move
across large parts of the island for searching their foods such as seeds and
other foods.
Breeding
The
Cockatoos are exclusive breeders, with couples they make great relationships
that can last several years. Numerous birds pair-up in the group prior to reaching
sexual maturity age but delay the breeding process at least for one year. The females
breed initially from 3 to 7 years of age and males are then mostly older. The Cockatoos
can also show site loyalty, returning to same nesting-sites in following years.
Dating is usually simple, mostly for recognized couples, with black-cockatoos alone
engaging in dating feeding. The known pairs engage themselves in grooming each
other, but all the engagement culminates after incubation starts, perhaps because
of the strength of pair-bond.
The clutch size differs within the breed, with the palm Cockatoo and some other bigger
Cockatoos producing only one egg, whereas some smaller breeds lay 2 to 8 eggs. About
20% of the laid eggs are infertile. The females of black-cockatoos are provisioned
by males numerous times in a day. The incubation period of Cockatoos is dependent
on the species size.
Diet and Feeding
The
Cockatoos are multipurpose feeders and they eat a variety of foods including vegetable
items. The seeds are also a great diet for all parrot species. The galahs,
corellas and some black-cockatoos feed mostly on the ground while others mostly
feed in the trees. The western and long-billed Corellas have lengthened beaks
to excavate tubers and roots. Many breeds of Cockatoo feed on the canopy of the
trees.
Relationship with Humans
The
human activities can affect positively on some breeds of Cockatoo and also
affect negatively on other species. Numerous breeds of an open-country have promoted
significantly from anthropogenic variations to the landscape, with the excessive
increase in reliable seed-food sources, existing water and have also improved
well to a diet comprising foreign products. This advantage seems to be constrained
to Australian breeds, as Cockatoos preferring open-country outside Australia
have not become more plentiful. Mostly forest-dwelling breeds have suffered seriously
from habitat demolition; in the main, they seem to have a more particular food
and have not been able to include unusual food into their diet.
Agricultural Pests
Some
breeds of Cockatoos are grave agricultural pests. They are occasionally
controlled by shelling, poisoning or imprisonment followed by gassing. They can
be an irritation in city regions due to the demolition of the property. They keep
their beaks in the wild by mastication on wood but, in an urban area, they may
chew outside furniture, door and window frames; soft ornamental lumbers, for
instance, western red cedar is readily destroyed. Outside Australia, Tanimbar
Corella is a pest on “Yamdena Island” where it attacks the maize crops.
Intelligence
A
team of experts from Oxford University, the University of Vienna and the Max
Planck Institute conducted experiments on 10 untrained Tanimbar Corellas and
found that they were talented to solve difficult mechanical puzzles.
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