Amazons are not sexually dimorphic although small but overlapping differences in beak, head and body size do occur between the sexes. Incorrect attempts have been made to determine sex by these differences. Last year I bought a “pair” Double Yellow Heads which had major differences in body size and head size. However, surgical sexing revealed two males; no wonder the breeder had no success with this "pair"!

Methods of sexing presently being used include DNA blood sexing, chromosomal karyotype, and my favourite endoscopy. Although noninvasive techniques, which simply need a blood sample, are of no risk to the bird they only tell you the sex of the bird. We recently surgically re-sexed a Red Lored that had been DNA sexed as a female. Well the bird was a male and there was apparently a mix up in paper work between the lab, vet and owner!

Endoscopy has proved to be a more useful management tool, if performed by an experienced avian veterinarian, for it can also evaluate maturity, the general condition of many internal organs plus the bird will be immediately identified by a band. The presence of air sacs allows main organs to be viewed including testes and ovaries, making the bird an ideal patient for laparoscopic examination. This allows the veterinarian to make a health check on the bird long before any external signs of sickness are given by the bird.

The equipment required for endoscopy includes a light source, fibre-optic light guide, a small diameter endoscope and anaesthetic gas machine all of which can cost at least $5,000. Be careful when a veterinarian who does not have this equipment says that the risks of surgical sexing are too high and offers blood sexing. We have now surgically sexed about 1,200 birds with Avian Veterinarians in Guelph, Toronto and Montreal with only two loses. A very small surgical incision is made necessitating the use of isoflurane, the anaesthetic of choice. The two birds that died both had other complications, one was an extremely obese Maximillian Pionus and the other a baby African Grey with major crop burn plus the veterinarians involved were both inexperienced.

Veterinarians appear to be charging about the same for both procedures so the extra information from endoscopy (e.g. gonads are scarred) may save you a lot of time and effort. Both sexing procedures can be performed on young birds before they are sexually mature, which is useful for structuring breeding populations and exchanging birds at a younger age. Chromosomal karyotype (different from DNA blood sexing) can detect birds with genetic abnormalities such as triploids but these birds are rare. It is more important to know the quality of the internal organs of a bird which can be done in a very cost effective way by surgical sexing.

Leg banding is commonly done by most clinics surgically sexing. By convention, the right leg is banded for males, and the left is used for females. All of our birds are banded and we have only had a few minor problems. It is important that the space between the butt ends of an open band is as small as possible for if this gap if left too wide it could allow the cage wire to pass through thereby hooking the bird. The bird will then panic and may in the struggle break its leg or chew off its foot. Close bands on domestic reared babies are quite safe and are an important means of identification. They can verify that the bird is domestic since they can only be slipped on very young babies and if the breeder has kept good records, the parentage of the bird.

By:Hagen