Chromosomal analysis has the additional potential to identify chromosomal defects which may result in embryonic mortality. Some chromosomal abnormalities which have been identified include inversions, translocations and triploidy. An inversion occurs when a segment of a chromosome is removed, rotated 180 degrees and reunited with the chromosome. Such a bird may look normal but have poor breeding performance. Chromosome translocations occur when two segments of two different chromosomes are exchanged resulting in two different abnormal chromosomes. Such birds will exhibit approximately 50% reduction in fertility. In triploidy, the chick receives the normal one set of chromosomes from one parent, while receiving two sets of chromosomes from the other, resulting in three sets of chromosomes. Triploid parrots will invariably be infertile.

Avian Genetic Sexing Laboratory, Marc Valentine, Call ahead for test kit - 901-388-9548.

Sexing by DNA Probe

DNA probes have been developed which can accurately distinguish the DNA in the sex chromosomes of male and female birds. The DNA probe is a labeled DNA fragment cloned from the sex chromosomes. This fragment tags similar sequences in the DNA samples of many bird species and gives characteristic and sex-specific patterns for each taxonomic group. The examination of both sex chromosomes and the internal controls implicit in the method (species-specific patterns and DNA quality cross checks) make this method extremely accurate.

Samples for DNA sexing are stable and can be stored for years, therefore in questions of accuracy or identity, stored samples can be referred to. These samples are also suitable for DNA fingerprinting as a means of individual identification. Zoogen, Inc., 1105 Kennedy Place, Suite 4, Davis CA 95616 916- 756-8089.

Hormonal Sexing Methods

Sex determination by measurement of sex steroid hormones in feces, egg wastes or plasma has been used for sex determination as well as assessment of functional activity of reproductive organs. Fecal steroid analysis was extensively researched at San Diego Zoo but is not currently commercially available due to the inability to sex immature birds or birds with poor gonadal activity.

Vent Sexing

Palpation, examination or eversion of the vent is used for sexing avian species such as newly hatched poultry, waterfowl and ratites. A rudimentary copulatory organ is present in males of these species.

Sexual Dimorphism In Psittacines

A few physical characteristics can be helpful in determining gender in monomorphic birds. For most species these traits cannot be relied upon totally for pairing. Sexual dimorphism is reliable and definitive in some species. Eclectus Parrots (Eclectus sp.) are an example of striking sexual dimorphism in which the female is deep red and purple with a black beak, while the male is a brilliant emerald green with a yellow-orange beak. For many year the sexes were mistaken for separate species with obvious difficulties in captive propagation.

Size and shape of the head and beak may be an indication of sex. The male bird usually has a larger, broader head and heavier beak than the female. Males of some species, such as cockatoos, are often significantly larger than females.

Behavioral differences can be helpful in gender determination. Male birds will often sing a courting song and dance while the female observes. This is more common in passerines than in psittacines and is the most reliable way of sexing society finches. The characteristic courting song of a male cockatiel is usually apparent before chicks moult to adult plumage. A parrot that spends excessive time rooting around on the cage floor and shredding paper is likely to be a female attempting to build a nest. Male birds of many species tend to be more aggressive than females, with some notable exceptions such as Eclectus parrots and Buffon¹s macaws. Females tend to be more likely to bite and protest more loudly when restrained.

Observation of copulation does not assure that birds are properly paired. Homosexual pairing is uncommon if birds are allowed to choose their mates. Groups of large psittacines which are allowed to pair up in a group cage must be watched carefully, especially macaws. If one pair decides to breed, they may become very aggressive toward other birds in the cage.

Palpation of the pelvic bones is commonly used by aviculturists for sexing birds. The pelvic bones are located slightly caudal to the vent and can be palpated with the bird restrained in dorsal recumbency or in a standing position grasping a perch. The pelvic bones of the mature female are supposedly farther apart to allow her to lay eggs. In addition the pelvic bones of the female are supposedly more pointed while in the male they are more rounded and directed medially. When performed on known sex birds it has been highly inaccurate.

Sexual dimorphism is often found in Australian and Asian psittacine species whereas Neotropical (Central and South American) and African species are typically monomorphic. Birds which inhabit arid climates show a higher incidence of sexual dimorphism than jungle or forest species which may indicate more dependence on sight identification among species in arid climates. Intensive observation of a species may reveal slight dimorphic traits. If African Grey Parrots from the same region are observed, the females will appear lighter in color than males. Many birds (not typically psittacines) molt into a prenuptial plumage prior to the breeding season.

In most species which exhibit sexual dimorphism, immature birds resemble females. Some species such as Asian parakeet species which have ringed necks do not exhibit adult dimorphic plumage until 1.5 to 2.5 years of age after reaching sexual maturity. Surgical or laboratory sex determination techniques are the logical alternative to excessive holding time prior to accurate gender determination by dimorphic traits.

SEXUAL DIMORPHISM IN PSITTACINES

Parrots of Australian and Pacific Distribution

LORIDAE -
Most species are monomorphic. The head is usually larger in male birds.

Monomorphic genera
Pseudeos - Dusky Lory
Chalcopsitta - Black Lory, Duvenbodes Lory
Eos - Red Lories
Lorius - Chattering Lory
Vini - Blue Lories
Most Trichoglossus sp. - Rainbow lories

Dimorphic genera (species)
Charmosyna - Stella Lory (Charmosyna papou) - The female has a yellow patch on the rump and lower back which is absent in the male.
Apparent in red and black color morphs.

Red-Flanked Lory (Charmosyna placentis) - The male has bright red patches on the flank which are absent in the female. The male has bright blue cheek patches, while the female has yellow streaked cheek patches. Other less common members of the genus are also dimorphic.

Trichoglossus - (T. flavoviridis meyeri) Meyer¹s lorikeet - The male has a larger and brighter yellow ear patch than the female.

CACATUIDAE

CACATUINAE

Monomorphic genera
Probosciger - Palm cockatoo - Male is usually larger and has a larger beak. Size also varies geographically and with subspecies.

Dimorphic genera
Calyptorhynchus - Black cockatoos - Dimorphism is striking in some species and barely noticeable in others. In the Banksian cockatoo (C. magnificus) the male plumage is black except for bands of red in the tail whereas the female is dotted and barred with orange-yellow.

Callocephalon - Gang gang cockatoo - The male is slate grey with a red head and crest. The female has a grey head and crest and plumage that is barred with yellow-orange.

Cacatua and Eolophus - White and pink cockatoos. Adult birds, except for the Bare-eyed cockatoo (C. sanguinea) can usually be sexed by eye color. The female has a red iris, whereas the iris of the male if dark brown to black. A bright light may be needed to determine eye color in some species such as the moluccan cockatoo (C. moluccensis). The female of most species is smaller than the male. Red eyed males and dark eyed females have been reported and are more common in captive reared birds. The iris is brown in immature birds of both sexes.

NYMPHICINAE
Nymphicus - Cockatiel - Sex is easily determined in the wild type (grey) as the male has a large yellow facial patch and crest which is absent in the female. The primary flight feathers and tail feathers of the female are diagonally barred with white. Immature birds resemble females. Cinnamon lutino and fallow cockatiels can be sexed by the faint diagonal barring of the primary flight feathers in the females and in cinnamons a faint yellow mask in the male. Pied cockatiels can be sexed as greys unless heavily pied and these areas are white. Pearl cockatiel males loose their pearling when mature. White faced cockatiels are sexed as greys.

PSITTACIDAE

PSITTACINAE

Monomorphic genera
Cyanoramphus - Kakarikis

Dimorphic genera
Melopsittacus - Budgerigar - In the normal green variety the cere of the adult male is blue, whereas the cere of the adult female in pinkish-brown. This is not dependable in color mutations such as lutino, blue or white birds.

Platycercus - Rosellas - The male of most rosella species is slightly brighter than the female or immature. Female and young of several species have a row of white spots on the ventral surface of seven or eight primary and secondary flight feathers. These are lost by the male at the time they reach sexual maturity. Wing spots are retained in adult female Yellow Rosellas (P. flaveolus). Golden mantled rosellas (P. eximius), Mealy Rosellas (P. adscitus) and Stanley Rosellas (P. icterotis). Male Stanley Rosellas have red heads and bright yellow cheek patches, while females have green heads and dull cheek patches.

Psephotus - Red Rumped Parakeet - (P. haematonotus)- Most species in the genus exhibit sexual dimorphism. The male red-rumped parakeet has a red patch on the rump, while the female is drab. Other species are uncommon in aviculture.

Neophema - Grass parakeets - Sexual dimorphism varies from a slight variation in the Bourke¹s parakeet (N. bourkii) (the male has more blue and pink on the breast) to extreme sexual dimorphism in the Scarlet chested parakeet (N. splendida) (the chest is red in the male, green in the female).

Polytelis - Barabands, Rock Pebblars etc. - The males of this genus are typically larger and brighter in color than females and young birds. Female Barabands parakeets (P. swainsonii) lack the yellow feathers of the male. In Rock Pebblars (P. ) the ventral surface of the males tail is black, while tail feathers of the female are margined and tipped in pink. The male princess of Wales (P. alexandrae) is brighter in color and the bill is deeper red than the female. In many species the male has an elangated spatula tip on the third primary.

Aprosmictus - Crimson-winged parakeet - The male has a black mantle.

Alisterus - King Parrots - Sexual dimorphism is present in plumage and beak color of some species. Some subspecies of green-winged King Parrots (A. chloropterus) show dimorphism in the green patch on the wing which is absent in the female, but some subspecies are monomorphic. In Australian King Parrots (A.scapularis) the male is red and the female¹s head is green.

Roratus - Eclectus parrots - The male is brilliant emerald green with a yellow-orange beak. The female is red-maroon and purple with a black beak. The color difference is evident at the time of emergence of the first tail and contour feathers in chicks. The down of both sexes is black.

Tanygnathus - Great bills, Blue napes, and Muller¹s Parrots - The beak of the male Muller¹s parrot (T. mulleri) is red, and the beak of the female is white. The beak of the male Great billed parrot (T. megalorynchos) is much large than the female¹s.

Psittaculirostris - Fig Parrots - Most species are obviously dimorphic in plumage.

Psittrichas - Pesquet¹s Parrot - Male has a red line behind the eye which is absent in the female.

Parrots of Afroasian Distribution

PSITTACIDAE

PSITTACINAE

Monomorphic genera

Coracopis - Vasa or black parrots - Monomorphic in plumage, however the tissues of the vent in males is hypertrophied especially in breeding season.

Agapornis - Lovebirds - Commonly available species are monomorphic. Some species show definative dimorphism such as the Abyssinian Lovebird (A. taranta) in which the male has a red patch on the forehead and lores which is absent in the female. The male Madagascar Lovebird (A. cana) has a grey head while the female has a green head.

Psittacus - African Grey parrots - Very slight dimorphism is evident on close examination but should not be considered definitive. Females (P. erithacus erithacus) tend to be lighter grey than males and have red edging on the under tail coverts caudal to the vent. Tinmeh greys (P. erithacus timneh) are monomorphic.

Dimorphic genera

Psittacula - Ring-necks - All male birds in the genus have a ring encircling the neck or a wide black moustache ring. In some species this is lacking in the female and young while in some it is less prominent. Adult male plumage may not be evident until 1 1/2 to 2 1/2 years of age. In some species the beak color is different. The male Derbyan parakeet (P. derbyana) and some subspecies of the moustache parakeet (P. alexandri) have a red beak while the female¹s beak is black.

Loriculus - Hanging Parrots - Adult birds are dimorphic in plumage and in some species in eye color. In most species, the forehead and/or crown of the male is blue or red and it is green in the female.

Poicephalus - Senegals and related species - Some members of the genus show marked sexual dimorphism whereas other are monomorphic. The male red- bellied Parrot (P. rufiventralis) has a deep red- orange breast and abdomen whereas the female¹s breast is greenish-brown. The female Ruppell¹s Parrot (P. rueppellii) is more brightly colored than the male having a bright blue rump patch that is absent in the male. The senegal (P. senegalus) shows slight but unrelable dimorphism. The undertail coverts of the male are yellow or orange while the female¹s are greenish yellow to greenish orange.

Parrots of South American Distribution

PSITTACIDAE

PSITTACINAE

Monomorphic genera

Ara - Macaws

Andorhynchus - Hyacinth Macaw

Aratinga - Conures

Pyrrhura - Conures

Nandayus - Nanday Conure

Enicognathus - Slender billed and Austral Conures

Cyanoliseus - Patagonian Conure

Deroptyus - Hawkhead parrots

Myiopsitta - Quaker Parakeets

Rhynchopsitta - Thick-billed Parrots

Brotogeris - Bee Bee Parakeets

Pionus - Pionus Parrots

Pionites - Caiques

Amazona - Amazon Parrots - Most species are monomorphic. In the Spectacled Amazon (A. albifrons) the male has red marking on the cranial edge of the carpus and adjacent upper wing coverts on the dorsal side of the wing which are absent or reduced in the female. In the Yellow lored Amazon (A. xantholora) the female is duller and lacks white on the head and red facial markings which are found in the male. The adult male Yellow- faced Amazon (A. xanthops) has a patch of yellow- orange on the breast and abdomen which is reduced or absent in the female.

Bolborhynchus - Mountain Parakeets - Only one species, the golden-fronted Mountain Parakeet (B. aurifrons) is dimorphic. The male has yellow markings on the lores, forehead, throat and part of the cheek, whereas the female is predominantly green.

Dimorphic genera

Pionopsitta - Pileated Parrot - The male has a red head and the female has a green head. Dimorphism is evident in immature plumage. Other members of the genus are monomorphic and very rare in aviculture.

Forpus - Parrotlets -All species are dimorphic. In most species the male will have coloration on the rump or wings while the females are usually predominantly green.

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