A Better Life for Birds

Why Birds?

Birds presented a compelling case for applying animal DNA science. The reasons for needing to know the gender of a bird are many.  From the simple curiosity of pet bird owners, captive breeding programs, diagnosis of illnesses, to better understanding of wild bird populations.

With a few exceptions, birds have no external genitalia, and many species have no size or feather differences that distinguish gender (AKA sexual monomorphism).  As a research intern at the San Diego Zoo, Joy had a front row seat as scientists were trying to find an alternative to the “surgical sexing” of birds.

Sun-conures-parrots-DNA-test-294x254 “I witnessed many surgical sexing procedures.  It seemed pretty cruel, but necessary for breeding and the exchange of birds between zoos.”


Birds were strapped down and surgical procedure performed without anesthetic.  (Please note that in those days, the anesthetics for birds were more dangerous, and veterinarians could not put rare and endangered species at risk.)  A small incision was made on one side and a scope inserted to examine the abdomen for an ovary or testis.

There had to be a better way.

A researcher at the Zoo found that the ratio of female to male hormones in bird urine was predictive of the bird’s gender, however not with absolute accuracy. Many bird’s hormones fell into a gray zone and were not helpful. My husband (a genetics professor at UC Davis) and I started discussing using a genetic test for gender. Such a test should be black and white and work irrespective of age, specie, etc.  We started, with many fits and starts, to put together a strategy for developing a genetic test for sexing birds.

DNA Provided the Better Solution

We were interested in finding sections of DNA on the sex chromosomes of birds that we could detect. Just like us, the gender of a bird is determined by what sex chromosomes it inherited from its parents. If there are detectable differences between the Z and W then you can say which sex chromosomes a bird has and, hence, its gender. Best of all, it turned out that most (but not all!) bird species have very similar sex chromosomes so we were successful in designing a test that worked with most types of birds.


“Sex Made Easy”

You can imagine that it was a great alternative to surgical sexing and caught on fast. We called it “Sex Made Easy,” so you can imagine the fun we had with advertising. At first, we tested primarily the large pet birds such as Amazon parrots, African Greys, Macaws, Conures, etc.

Business Boomed!

In the mid 1990s, we had an unprecedented boost in business. There was a two year fad in breeding, buying and selling of ostriches and emus, a bubble which eventually burst as American farmers found the adoption of the meat was too slow and the birds too difficult to ranch.  In the meantime, the thousands of birds we serviced put our company at the forefront of the industry, with the ability to branch out into other sectors.

Two decades later, our business continued to service thousands of birds each year with an expanded repertoire including zoo avians, bird conservation projects, and falconry enthusiasts. The bird sexing test we developed is now regarded as the gold standard in accuracy.

Achieving the Gold Standard

Reporting on their research to develop in-house sexing of birds from eggshells, San Diego Zoo scientists cited our company, Zoogen, in reference to the DNA test: “All of the birds used in the study were of known sex as determined by laparascopy (surgical sexing),  behavior, morphology, or Zoogen sexing.”  Zoo Biology 22:561-571 (2003).

Perpetua Life Jewels

In 2014, we sold the avian DNA testing business to Antech Diagnostics, to spend more time on the Perpetua Life Jewels at home with my family and animal companions.