Many species of birds are sexually dimorphic and can be sexed visually once they are adults. The most outstanding case is in eclectus parrots: the male is bright green and the female is red and violet. Check up on the species you have to see if it is dimorphic. If you have a budgie, cockatiel or kakariki you can visit my species profiles to find out how they can be sexed visually.
DNA sexing is easy and non-intrusive. Many places provide this service, I use Zoogen. Call the company up and they will send you a vial and some instructions. All you have to do is clip a toenail and gather a drop or two of blood. It's easy and it only costs about $20.
Surgical is still done though it's dying out since DNA techniques were developed. It's much more dangerous- it involves anesthesizing the bird, making a small incision and inserting a scope to view the reproductive organs. It is also less accurate.
Behavior is what I use to sex my pet birds. It's free and very simple if you know what to look for. When birds become sexually mature they tend to act a certain way. Males will often try to mate with their owner's hand or head and females will often crouch and coo, begging to be mounted. Both sexes may regurgitate or rub their cloaca on things.
All articles and images contained on this site are © 1998, 1999 by Feisty Feathers unless otherwise noted and may not be reprinted or used in any way without the author's permission.