Determine Bird’s sex by DNA Testing

Avian DNA testing technique has emerged as a reliable method of determining bird’s gender in recent times. It is in fact a non-surgical way of finding out avian gender. Various species of birds like parrots, finches, cockatoos, lorikeets, raptors, etc., can easily be gender tested by this method. However, parrot sexing is the most common of all.

The need for DNA sexing arises as the physical traits or characteristics fail to provide the bird owners, breeders, and veterinarians with an exact determination of bird’s sex, particularly when one needs to wait until the bird attains maturity in order to find its gender by examining the physical characteristics.

How it works

Avian DNA sexing is based on significant biological fact that the chromosomal or genetic structure of the male and female bird is different. Actually, in female bird, the pair of sex determining chromosome comprises of two different chromosomes, Z and W unlike humans which have an X chromosome and a Y chromosome. Male bird carries two Z chromosomes in its pair of sex determining chromosome. In the bird DNA sexing, the PCR technique of molecular diagnostics is utilized whereby the particular region of bird DNA across the sex chromosome is amplified to several orders of magnitude. Since, the female bird carries two different sex chromosomes, Z and W, the PCR test gives two resulting profiles, one from each of the chromosome. On the other hand, the male bird having same sex chromosome, Z and Z, gives only one product for the PCR test. in this case, since female birds have ZW chromosomes and males have ZZ chromosomes, it is the female that determines whether the offspring will be male or female.

Sample for bird sexing

Bird DNA sexing tests can be carried out either on a feather of the bird or on blood sample. The former technique is known as feather sexing while the latter is called blood sexing. Contrary to popular notion, the results from both samples are the same, as in both the cases the DNA molecule of the bird is subjected to the test and it remains the same irrespective of the source from which it is taken.

Blood sexing

It involves gently clipping the toenail of bird short enough with a sterilized clipper so that blood appears which is then collected on the sample card for testing. In feather sexing, medium-sized mature feathers are plucked from the chest area of the bird and carefully packed in sealed bags so that the tip of the feather attached to the skin is left undisturbed. The DNA testing is then performed on these feathers.

Avian DNA relation test

Bird DNA relation tests are performed to determine the extent of relatedness present between two birds. This test helps in managing healthy breeding between best pair of birds and reducing the problems of uncontrolled inbreeding. Thus, favourable characteristics of birds are passed onto the progeny and such problems like low fertility, decreased tolerance to climate, shorter life span, etc., are avoided.

In relationship test, the DNA profile of each bird with its distinct bands is created and matched with that of the other birds to determine the rate of shared bands. In case, the rate of shared bands, called the band sharing frequency (BSF), is low then it means the degree of relatedness between the two birds is not significant and hence, they are the best pairs for breeding. When the BSF is high, then it indicates that the birds have common ancestors in pedigree, are siblings, or may be parent and offspring. Thus, high BSF pairs are not considered for breeding purposes.

Conclusion

Avian DNA sexing is useful for various reasons, health being the primary one. Knowing the bird’s gender helps in dealing with physical ailments of the bird accordingly and required for good bird parenting in general. Further, relationship tests help in controlling breeding activities in birds to promote healthy features in birds and increase their survival rates.