Sulphur-crested Cockatoo
FAMILY: Cacatuidae
GENUS: Cacatua
SPECIES: galerita
Description:
Large conspicuous white
cockatoo with yellow crest frequently raised in alarm or display. Beak and feet
black. No sexual dimorphism. Males are distinguished from females by the colour of the eye; females have slightly lighter (reddish) coloured irises than males, although many females have a
blackish iris (like the males). There is also some marginal difference in the
size of the head and general stature. Males have slightly larger heads and when
in pairs usually stand taller with legs apart giving an overall dominant
appearance.
Immature birds resemble adults but are extremely difficult to sex.
Length:450-500mm.
Distribution:
Across northern and
eastern Australia.
Habitat:
Forests and woodlands
including wet sclerophyll and rainforest.
Diet:
Seeds, grains, nuts,
fruits, bulbs, fruits, insects and insect larvae.
Breeding:
May-September in the
north, August-January in the south.
Usual nesting site is a
large hollow limb or a hollow tree trunk most often at least 10m above ground.
It appears that tall eucalypts close to or bordering water courses are
preferred nesting sites. Both males and females prepare the nest by chewing around
the entrance and inside the hollow which may be excavated to some depth. The
nest base is rotten wood.
In captivity hollow
eucalypt logs are best suited for breeding. The log should be approximately
35-40 cm in internal diameter and about 1m in length. The log should be
suspended vertically or in an inclined position. Some birds prefer entrances at
the front of the log, whereas others prefer an entrance on top. The preferred
nesting material is a mixture of wood shavings and dirt or peat moss.
Courtship Display
Male Sulphur-crested
Cockatoos strut towards females with the crest erect and tail feather spread
wide. He also nods/bobs and flicks the head from side to side whilst emitting a
low chuckling call. These displays are often performed during the process of
nest preparation and many such displays usually precede the actual copulation.
Sexual Maturity
These birds usually
breed at 4-5 years of age. However, this may not always be the case. There are
records of Sulphur-crested Cockatoos breeding at 2 years
of age but this is under rather unusual circumstances such as in an
overabundance of food. Similarly, sexually mature pairs may not breed until 6
or 7 years of age, depending on prevailing circumstances.
Clutch:
1-3 white oval eggs.
Incubation period: 30days. Fledging usually occurs at 9 to 12 weeks. Chicks
remain with the parents for an indefinite period thereafter however.
Mutations and Hybrids:
Lutino Sulphur-crests are
similar to the normal variety but with a pale beak and flesh coloured feet and eyes.
Hybrids have been
recorded with Major Mitchell, Galah, Little
(short-billed) and Slender- (long) billed Corellas
Suitable Aviaries and Compatible Birds
Historically, this
species has been kept as a pet bird and most of us are probably aware of the
typical "cocky-cage". As a minimum, a single bird may be housed in
such a cage provided it measures at least 800mm x 600mm x 1200mm
(approximately). Pairs can be kept in a slightly larger cage. However, these
birds always fare better (and look more spectacular) in larger aviaries. These
should be somewhere in the vicinity of 2m wide x 2m high x 5 or 6m long so as
to provide amply flight space and to accommodate nesting logs etc.
The wire should be of a heavy duty grade, as cockatoos easily chew holes in
lighter grade wire. Similarly, the frame should be constructed of steel to
avoid the birds chewing the structure away.
Species Specific Problems
Intestinal worms are a
common problem in species which spend considerable time on the ground.
Similarly, fungal infections may become a problem. These are relatively easily
dealt with however simply by maintaining a high standard of hygiene. Another
problem encountered in this species is Psittacine
beak and feather disease. This is an incurable disease which is transmitted
through feaces. Essentially, it results in poor
feather growth and feathers which don't replace themselves when they fall out.
Similarly, the beak is also affected and becomes fragile and does not repair
itself. The bills of birds with this condition have a deep black, glossy
appearance rather than the normal chalky grey colour.
It is advisable to test birds suspected to have this condition. The best course
of action for affected birds is to destroy them as there is no cure. Infected
birds will infect their offspring simply by feeding them as there is always chances of contact with faeces
in the nest and during feeding of the young.
Feather plucking is also common to Sulphur-crested
Cockatoos. This has a range of causes and can usually be rectified.