Macaw Compendium
Introduction to Psittacine Birds
General:
The Psittaciformes (parrots, lories, cockatoos, parakeets) are an
unique order within the birds of this world. In taxonomic systems
they are normally filed between the Columbiformes (Pidgeons) and
Cuculiformes (Cuckoos and Touracos).
The psittacine birds exist in all shapes and sizes.
The size varies from 8.5 cm in Pygmy Parrots to 100 cm in the Macaws and
the colors from a dull dark brown (Vasa Parrot) to bright colorful mixtures
of red, green, blue and yellow. (Sun Conures, Lories). Often sexual
dimorphism is absent but also in some genera/species very obvious.
Typical:
One of their typical sign is the big head with a bended strong
beak. The upper part is curved downward, ending in a sharp tip and fits over
an upward curved lower mandible with a broad front.
The upper mandible of the beak is movable against the head with an
extra angle and muscles, while in other birds this mandible is blocked to the
skull and more or less unmovable. The special mechanism of muscles for the beak
(crosswise up and down) gives great power.
The broad and fleshy tongue is strengthened by a horny layer under the tip.
Beak and tongue together make an excellent tool for cracking seeds, wood
carving, digging holes etc. or are used as "third hand" while climbing and
to examine things.
The nostrils are placed in a naked or feathered fleshy cere at the base of
the upper mandible.
Also the zygodactyl feet (two toes forward, two back) are obvious and
give them excellent ability in climbing and manipulating things. The outer
toes are prolonged against the inner.
Compared to other orders of birds the Psittaciformes have less but stronger
feathers. The parson's nose is reduced and there are special powder dunes
which produce a fine mealy dust to conserve the plumage.
Generally a psittacine bird has 12 tailfeathers. The shape of these feathers
varies within the genera/species.
The feathers of the Psittaciformes contain a specific group of pigments,
called Psittacin which in combination with others lead to the beautiful
colors that are found in these birds.
Environment:
These birds live in a
great variety of environments from hot tropical rainforests to nearly
antarctical climate. Many of their species are highly specialized in
nutrition and biotop requirements. Others seem to be cosmopolites.
There are more than 330 different species distributed from equatorial to
near antarctical regions of the world. Some species like Myiopsitta (Quaker)
or Psittacula sp. (Ringnecks) which escaped from captivity have settled
successfully in cities and parks which do not form their native environment.
Nesting:
With little exceptions they nest in hollows of old trees, termite buildings
or hollows of steep river banks and mountain slopes. The hatched birds are
very weak and take a long time to develop until fledging. This is typical for
birds which nest in hollows. Depending on the
environment there is a more or less clear defined breeding season.
Eggs are normally of white color. The clutch may contain from one
or two (Kakapo) up to eight eggs (Nymphicus, Touit and others).
Social Behavior:
Outside the
breeding season parrots in general are very social birds which gather in flocks
from small parties to thousands in number. This instinctive socialization
soon made them pets in human history. Kept in captivity parrots are forced
to take man as flock-social partner by instinct if there is no natural partner
availibale.
Pair bonding is very strong. Young parrots may choose their lifetime
partners before maturity. In some of the species it is even possible that a
bird will die after the loss of it's mate.
Natural History:
Fossile relicts of birds are rare,
so the development of the families/genera cannot be tracked back clearly.
The great differences between the geographical groups and the lack of
intermediates between most of the families leads to the conclusion that
the "endemic development" of Parrots started in early history of the aves.
The oldest fossile parrot has been found in Great Britain and is dated
from the early Eocene - more than 60 million years ago.
It could be identified as some sort of conure by the specific form
of tibia-bones parrots have in their feet (zygodactylism).
It is believed that under the existing psittacines
Strigopidae (Kakapo) and
Nestoridae (Kea, Kaka) show the oldest living forms of these birds.
Human History:
In human history we know of the first parrots brought to the ancient Greece.
At the court of Artaxerxes II, the pysician Ctesias gave a description of the
Plum-headed Parakeet and noticed it's ability to speak. Parrots from the
genus Psittacula were well known in ancient Rome and with the discovery of
the New Worlds in the 15th and 16th century the trade in live parrots
started to become a regular business.
Nowadays the world-wide trade of live psittacines has reached such an extent
that there is an urgent need for controlling. Also the business brought many
of the species to the fringe of extinction and many efforts have to be
taken to preserve of what is left.
Another reason for the decline of the parrots
as well as other animals of the world is the destruction of
habitats and environments by humans which regardless the known problems
increases year by year.
Captivity:
Because of their instinctive social behavior parrots always have been famous
as pets. Humans are accepted as flock-partners and it is possible to touch
the bird because preening is an expression of partnership within the
psittacines. They may learn to imitate human voices - and even use it to
communicate with their human partners. The great capability to learn certain
tricks and behavior which is not typical for the wild bird is another reason.
Rearing and keeping parrots is not the topic of this compendium. It just
gives you a short impression about the (nowadays) existing macaws.
Intelligence:
The broad skull of the Psittaciformes gives room for a more extended brain
than in other birds. Well known is their great capability to learn. In
captivity many parrots can learn to imitate human language and also may
even use it to express their needs.
Researches (Pepperberg et al.) have shown that is possible for a parrot
to identify "same" and "different" attributes of known and unknown
items and to express this in human language.
But as in all "intelligent" beings
the individual's character varies very much. - One African Grey Parrot will
learn to speak easily while the other refuses to learn a single word.
You should have a look at
"Pepperberg Pages" for further information on this subject.
Mortality:
Left aside human influences it is estimates that the loss under young
psittacines is as high as in other birds. Only in Australia wild parrots
are banded or receive wing-tags for field observations, so no secure data
about the lifespans of parrots in general is availiable.
Well known is the longevity in captive parrots. There are proved records of
larger birds like Cockatoos and Amazons which reached an age of
more than 100 years.
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Created for the Macaw's homepage Feb. 1996
pfeffer@club.tu-clausthal.de