Sexing Question

[stephend]

So I have been watching "The Life of Birds" on netflix and it showed that some birds whose sexes are indistinguishable by inspection appear quite different under black light. I was wondering if anyone had checked their birds for this feature.

 

[IolaniAviary]

I have read only some on this, it is only certain species. I have heard that it does not work on many small parrots, and some large. I also know that it depends on the strength of the bulb. It's not just a matter of putting a black light in a room you have to have a small light with the correct strength close to the bird.