| Copyright © Linda S. Rubin | CockatielsPlusParrots.com |
Home | Bio | Books | Magazine | Presentations | Calendar | Blog | Contact Us | Terms of Use | Sitemap
| Male Gang-gang Cockatoo © 2005 Linda S. Rubin |
| Normal Grey Cockatiel © 2005 Linda S. Rubin |
Linda S. Rubin has raised and kept cockatiels and parrots since 1976 and is the author of several books at www.CockatielsPlusParrrots.com. She
is the Founding President of the Cockatiel Foundation, Inc., Specialty Organization Vice President of the American Federation of Aviculture, Inc., and
a Certified Panel Judge for the Cockatiel Foundation and the Society of Parrot Breeders & Exhibitors, Inc.
is the Founding President of the Cockatiel Foundation, Inc., Specialty Organization Vice President of the American Federation of Aviculture, Inc., and
a Certified Panel Judge for the Cockatiel Foundation and the Society of Parrot Breeders & Exhibitors, Inc.
| Parrot Articles |
 | |  | |  | |  | |  | |  | |  | |  |
 | |  | |  | |  | |  |
It is generally understood that Cockatiels are quite prolific and a greater number can be reared in captivity compared to many species of
cockatoos. Because Cockatiels can be raised in greater numbers within a shorter span of time, lessons may be more quickly learned
concerning husbandry and other aspects of aviculture. In some instances, this knowledge could be considered where appropriate, perhaps
concerning some aspects of health, genetic predisposition to disease, husbandry, nutrition and possibly further evolutionary questions
involving environmental adaption.
For example, many cockatiel breeders feed low-fat diets (e.g., it does seem that Cockatiels can simply “glance” at a seed and appear to gain 5
grams). Feeding a diet low in fat to Cockatiels can assist in preventing a shortened lifespan, as well as some difficulties in reproduction and
various health issues (i.e., weight gain can prompt a propensity for growing tumors and other health issues, especially when space is restricted
in captivity). We already know these issues similarly appear to affect the Galah. A significant pool of knowledge in Cockatiel culture has
already accumulated over the decades and could prove useful in providing a wider view or a reference when examining this family of birds.
Strides in nutrition and avian medicine have added greatly to keeping and raising avian species in captivity, and Cockatiels have benefited from
many formal studies and observations providing noteworthy information. Additionally, cockatiel breeders throughout the world have
established various gene pools of Cockatiels and their mutations, which might prove informative as a reference. Fortunately for aviculturists, a
unique study was undertaken some years ago to address the evolution of cockatoos, which revealed some fascinating results.
Researchers at the University of California, at Davis, David M. Brown, a Ph.D. student at UCLA and Dr. Catherine A. Toft, professor at the
Center for Populations Biology at UC Davis, conducted the study, "A Cockatoo's Who's Who: Determining Evolutionary Relationships
Among the Cockatoos." The study was published in volume 11, No. 2. of the Exotic Bird Report in the Psittacine Research Project of
the Department of Avian Sciences at the University of California at Davis, which highlighted intriguing new findings.
To start, Brown and Toft acknowledged a lengthy history of the exhaustive work by other researchers identifying 350 species of parrots,
beginning with Linnaeus in 1758, and which revealed the following facts before Brown and Toft began their own investigation.
First, it was found that cockatoos form a unique group in themselves among the parrots. Some of the more notable morphological
characteristics include an erectile crest that can be lowered and raised at will (aiding many observers to be able to explain and interpret
cockatoo body language), plus a lack of dyck texture in feathers that other parrots utilize in order to produce the blue and green colors that
appear in their plumage.
Second, it was noted that cockatoos have traditionally been divided into two major groups, the predominantly black Calyptorhynchi,
Calyptorhynchus, and the predominantly white Cacatuini, including Cacatua.
The goal of the researchers was to establish both the evolutionary relationships between the cockatoos, as well as to determine an exact
hierarchal order in which the cockatoos descended from a common cockatoo ancestor. The second question to consider was at what point
in the evolution did the Gang-gang, Galah and Major Mitchell cockatoos depart from their common cockatoo ancestor? A major element in the
research was to determine whether or not a Cockatiel is actually a cockatoo. And, if it turns out that the Cockatiel truly is a cockatoo, to which
group of cockatoos is the Cockatiel most closely related.
Researchers Brown and Toft built an evolutionary tree by sequencing a segment of mitochondrial DNA (a region of the ribosomal 125 gene)
from 15 of 19 species of cockatoos. The researchers found that the genetic evolutionary tree confirmed the following results.
It was found that the first species to diverge from the common cockatoo ancestor was the Palm Cockatoo, followed by a a group that included
the Gang-gang cockatoo, the Red-tailed cockatoo - and - the Cockatiel. Later descendants to follow included the Galah, the Major Mitchell’s
and finally, the two groups of white cockatoos.
It was also discovered that the sexually dimorphic species that readily identified their gender differences such as the Gang-gang, Red-tailed
Black and the Cockatiel, are in fact more closely related to one another than to any other species of cockatoo. Additionally, it was specifically
mentioned that the shared trait of sexual dimorphism by the above species is probably inherited from a common ancestor, as opposed to
evolving as an independent trait.
Of significant import, it was determined that the Cockatiel is indeed a cockatoo and is most closely related to the black cockatoos in the
genus Calyptorhynchus (the Red-tailed, Yellow-tailed, White-tailed and Glossy Cockatoo), and the Gang-gang Cockatoo of the genus,
Callocephalon.
Additional research revealed that the white cockatoos that include the Moluccan, Blue-eyed, Greater Sulphur-crested and Lesser Sulphur-
crested cockatoos most notably shared prominently colored crests, rounded wings and heavy beaks.
Furthermore, the remaining group of white cockatoos containing the Red-vented, Little Corella, Ducorp’s and Goffins carried shorter crests,
slender wings and smaller beaks.
Interestingly, the primarily deep pink cockatoos that include the Galah and Major Mitchell’s - based on the researcher’s DNA data - very
likely evolved after the Palm Cockatoo and black cockatoo groups (including the Cockatiel), but prior to the existence of the two white
cockatoo groups. This fact indicated that the two white cockatoo groups did not evolve on the evolutionary tree until much later or further
along.
Finally, it was determined that cockatoo species that originated at the base of the evolutionary tree are distributed across Australia. It was
also found that cockatoo species that split from their common ancestor, evolving in more recent history, spread northward to New Guinea,
Indonesia and the South Pacific Islands.
Many cockatiel enthusiasts have long regarded the Cockatiel as a miniature cockatoo. The nominant grey Cockatiel in its wild form is more
closely aligned to the black cockatoos, sharing their darker color, distinctive cheek patches and under tail-barrings. It is easy to see how the
smaller, wild, dark grey Cockatiel could be related to the black Red-tailed, Yellow-tailed, White-tailed and Glossy cockatoos sharing similar facial
cheek marking, scalloping, flecking, spottings and under-tail barrings. Even the mutation Cockatiels of today, such as the newer Yellow-cheek
and Golden-cheek cockatiel mutations, among others, display the cheek markings of some of its larger cousins.
Cockatiels similarly share the same unique powder-down feathers and lack of dyck feather texture that prevent them from displaying any
authentic green or blue feather colors as seen in other Psittacine birds. Many aviculturists are aware that the Whiteface cockatiel is the genetic
form of the blue allele, which can also be seen in the “blue” mutation form of the Galah cockatoo.
In more recent years two examples of a successful hybridization between the Cockatiel and the Galah have produced at least two known
“Galatiels” in two Australian aviaries. These babies were viewed at conventions and verified by other aviculturists and their story is
documented in several Australian avicultural consumer magazines. Videotapes were also released for wide viewing.
Cockatiels share the cockatoo’s erectile crest, characteristic of all cockatoos, and an obvious enthrallment for endless head scratching
sessions, but with a bonus of vocalizing with a much quieter voice.
The Cockatiel – or smallest of cockatoos – with many of the characteristics of a large cockatoo built into a much smaller “package,” make it an
excellent alternative for anyone who cannot keep a larger cockatoo. And, because of its propensity to reproduce quickly, a closer study might
prove useful for possible reference when considering cockatoo behaviors or other aspects of cockatoo culture.
Aviculturists can be grateful to researchers Brown and Toft for forging the answers to these intriguing questions that once held long debate.
Many an aviculturist working with reproducing Cockatiels will be surprised to learn that they are, in fact, a breeder of Cockatoos - albeit, “the
littlest cockatoo.”
To learn more about avian research at UC Davis, or to make a donation to future projects, contact: The Psittacine Research Project, Department
of Animal Science, University of California, One Shields Avenue, Davis, CA 95616-8521.
Reference:
Brown, David, M., and Toft, Catherine, A. A Cockatoo’s Who’s Who: Determining Evolutionary Relationships Among the Cockatoos. Exotic Bird Report, Volume 11, No.
2. Psittacine Research Project, Department of Avian Sciences, University of California, Davis, CA.
cockatoos. Because Cockatiels can be raised in greater numbers within a shorter span of time, lessons may be more quickly learned
concerning husbandry and other aspects of aviculture. In some instances, this knowledge could be considered where appropriate, perhaps
concerning some aspects of health, genetic predisposition to disease, husbandry, nutrition and possibly further evolutionary questions
involving environmental adaption.
For example, many cockatiel breeders feed low-fat diets (e.g., it does seem that Cockatiels can simply “glance” at a seed and appear to gain 5
grams). Feeding a diet low in fat to Cockatiels can assist in preventing a shortened lifespan, as well as some difficulties in reproduction and
various health issues (i.e., weight gain can prompt a propensity for growing tumors and other health issues, especially when space is restricted
in captivity). We already know these issues similarly appear to affect the Galah. A significant pool of knowledge in Cockatiel culture has
already accumulated over the decades and could prove useful in providing a wider view or a reference when examining this family of birds.
Strides in nutrition and avian medicine have added greatly to keeping and raising avian species in captivity, and Cockatiels have benefited from
many formal studies and observations providing noteworthy information. Additionally, cockatiel breeders throughout the world have
established various gene pools of Cockatiels and their mutations, which might prove informative as a reference. Fortunately for aviculturists, a
unique study was undertaken some years ago to address the evolution of cockatoos, which revealed some fascinating results.
Researchers at the University of California, at Davis, David M. Brown, a Ph.D. student at UCLA and Dr. Catherine A. Toft, professor at the
Center for Populations Biology at UC Davis, conducted the study, "A Cockatoo's Who's Who: Determining Evolutionary Relationships
Among the Cockatoos." The study was published in volume 11, No. 2. of the Exotic Bird Report in the Psittacine Research Project of
the Department of Avian Sciences at the University of California at Davis, which highlighted intriguing new findings.
To start, Brown and Toft acknowledged a lengthy history of the exhaustive work by other researchers identifying 350 species of parrots,
beginning with Linnaeus in 1758, and which revealed the following facts before Brown and Toft began their own investigation.
First, it was found that cockatoos form a unique group in themselves among the parrots. Some of the more notable morphological
characteristics include an erectile crest that can be lowered and raised at will (aiding many observers to be able to explain and interpret
cockatoo body language), plus a lack of dyck texture in feathers that other parrots utilize in order to produce the blue and green colors that
appear in their plumage.
Second, it was noted that cockatoos have traditionally been divided into two major groups, the predominantly black Calyptorhynchi,
Calyptorhynchus, and the predominantly white Cacatuini, including Cacatua.
The goal of the researchers was to establish both the evolutionary relationships between the cockatoos, as well as to determine an exact
hierarchal order in which the cockatoos descended from a common cockatoo ancestor. The second question to consider was at what point
in the evolution did the Gang-gang, Galah and Major Mitchell cockatoos depart from their common cockatoo ancestor? A major element in the
research was to determine whether or not a Cockatiel is actually a cockatoo. And, if it turns out that the Cockatiel truly is a cockatoo, to which
group of cockatoos is the Cockatiel most closely related.
Researchers Brown and Toft built an evolutionary tree by sequencing a segment of mitochondrial DNA (a region of the ribosomal 125 gene)
from 15 of 19 species of cockatoos. The researchers found that the genetic evolutionary tree confirmed the following results.
It was found that the first species to diverge from the common cockatoo ancestor was the Palm Cockatoo, followed by a a group that included
the Gang-gang cockatoo, the Red-tailed cockatoo - and - the Cockatiel. Later descendants to follow included the Galah, the Major Mitchell’s
and finally, the two groups of white cockatoos.
It was also discovered that the sexually dimorphic species that readily identified their gender differences such as the Gang-gang, Red-tailed
Black and the Cockatiel, are in fact more closely related to one another than to any other species of cockatoo. Additionally, it was specifically
mentioned that the shared trait of sexual dimorphism by the above species is probably inherited from a common ancestor, as opposed to
evolving as an independent trait.
Of significant import, it was determined that the Cockatiel is indeed a cockatoo and is most closely related to the black cockatoos in the
genus Calyptorhynchus (the Red-tailed, Yellow-tailed, White-tailed and Glossy Cockatoo), and the Gang-gang Cockatoo of the genus,
Callocephalon.
Additional research revealed that the white cockatoos that include the Moluccan, Blue-eyed, Greater Sulphur-crested and Lesser Sulphur-
crested cockatoos most notably shared prominently colored crests, rounded wings and heavy beaks.
Furthermore, the remaining group of white cockatoos containing the Red-vented, Little Corella, Ducorp’s and Goffins carried shorter crests,
slender wings and smaller beaks.
Interestingly, the primarily deep pink cockatoos that include the Galah and Major Mitchell’s - based on the researcher’s DNA data - very
likely evolved after the Palm Cockatoo and black cockatoo groups (including the Cockatiel), but prior to the existence of the two white
cockatoo groups. This fact indicated that the two white cockatoo groups did not evolve on the evolutionary tree until much later or further
along.
Finally, it was determined that cockatoo species that originated at the base of the evolutionary tree are distributed across Australia. It was
also found that cockatoo species that split from their common ancestor, evolving in more recent history, spread northward to New Guinea,
Indonesia and the South Pacific Islands.
Many cockatiel enthusiasts have long regarded the Cockatiel as a miniature cockatoo. The nominant grey Cockatiel in its wild form is more
closely aligned to the black cockatoos, sharing their darker color, distinctive cheek patches and under tail-barrings. It is easy to see how the
smaller, wild, dark grey Cockatiel could be related to the black Red-tailed, Yellow-tailed, White-tailed and Glossy cockatoos sharing similar facial
cheek marking, scalloping, flecking, spottings and under-tail barrings. Even the mutation Cockatiels of today, such as the newer Yellow-cheek
and Golden-cheek cockatiel mutations, among others, display the cheek markings of some of its larger cousins.
Cockatiels similarly share the same unique powder-down feathers and lack of dyck feather texture that prevent them from displaying any
authentic green or blue feather colors as seen in other Psittacine birds. Many aviculturists are aware that the Whiteface cockatiel is the genetic
form of the blue allele, which can also be seen in the “blue” mutation form of the Galah cockatoo.
In more recent years two examples of a successful hybridization between the Cockatiel and the Galah have produced at least two known
“Galatiels” in two Australian aviaries. These babies were viewed at conventions and verified by other aviculturists and their story is
documented in several Australian avicultural consumer magazines. Videotapes were also released for wide viewing.
Cockatiels share the cockatoo’s erectile crest, characteristic of all cockatoos, and an obvious enthrallment for endless head scratching
sessions, but with a bonus of vocalizing with a much quieter voice.
The Cockatiel – or smallest of cockatoos – with many of the characteristics of a large cockatoo built into a much smaller “package,” make it an
excellent alternative for anyone who cannot keep a larger cockatoo. And, because of its propensity to reproduce quickly, a closer study might
prove useful for possible reference when considering cockatoo behaviors or other aspects of cockatoo culture.
Aviculturists can be grateful to researchers Brown and Toft for forging the answers to these intriguing questions that once held long debate.
Many an aviculturist working with reproducing Cockatiels will be surprised to learn that they are, in fact, a breeder of Cockatoos - albeit, “the
littlest cockatoo.”
To learn more about avian research at UC Davis, or to make a donation to future projects, contact: The Psittacine Research Project, Department
of Animal Science, University of California, One Shields Avenue, Davis, CA 95616-8521.
Reference:
Brown, David, M., and Toft, Catherine, A. A Cockatoo’s Who’s Who: Determining Evolutionary Relationships Among the Cockatoos. Exotic Bird Report, Volume 11, No.
2. Psittacine Research Project, Department of Avian Sciences, University of California, Davis, CA.
In the discussion of cockatoo evolution, it appears a long debate has been answered that would shed light
on the cockatoo’s family structure, including the order and relationship of various genera to one another
and just how closely they are related. Pivotal to this exploration and an adjunct to the question of cockatoo
ancestry is whether or not the Australian Cockatiel is an actual member of the cockatoo family. The latter
is an important question not limited to cockatiel enthusiasts. Should it be found that the Cockatiel is
indeed a cockatoo - and the genera to which it is related is identified - perhaps some parallels might be
drawn that could prove beneficial to cockatoo culture at large, or to some species of the cockatoo family.
on the cockatoo’s family structure, including the order and relationship of various genera to one another
and just how closely they are related. Pivotal to this exploration and an adjunct to the question of cockatoo
ancestry is whether or not the Australian Cockatiel is an actual member of the cockatoo family. The latter
is an important question not limited to cockatiel enthusiasts. Should it be found that the Cockatiel is
indeed a cockatoo - and the genera to which it is related is identified - perhaps some parallels might be
drawn that could prove beneficial to cockatoo culture at large, or to some species of the cockatoo family.
| INTRODUCTION |
| RESEARCH STUDY |
| EVOLUTIONARY RELATIONSHIPS |
| ANOTHER COCKATOO |
| FUTURE STUDIES |
| THE GENETIC EVOLUTION OF COCKATOOS Which Genera Arrived First? Is a Cockatiel a Cockatoo? ©2002 Linda S. Rubin, CF & SPBE Panel Judge All Photos and Articles “All Rights Reserved” by Author. Written permission from author required for reprints. First published in the June 2002 issue of BIRD TALK magazine. Subsequently published in: August 3, 2006 issue of CAGE & AVIARY BIRDS (United Kingdom) October, 2006 issue of TALKING BIRDS (Australia) Volume XXXVIII, No. 1/2, 2011, American Federation of Aviculture, Inc. AFA Watchbird Journal October/November/December 2011 Society of Parrot Breeders & Exhibitors SPBE Journal |
| Unique Avian Solutions for Breeding, Genetics, and Companion Parrots |