New Sexing Method for Diamond Firetails
Posted: 30 Dec 2010, 22:00
New Sexing Method for Diamond Firetails
by Danny Searle
It is a well know fact that birds see in perfect colour vision. With this in mind I have often wondered why many finch species are “Monomorphic”.
Monomorphic refers to those species where the sexes appear identical. If they see in colour, why then would the cocks look like hens? I then remembered that many birds, like Budgerigars can also see in Ultraviolet. Ultraviolet is a wavelength too high for humans to see. Ultraviolet lights are sometimes referred to as “black lights”. They make white shirts and teeth glow, and hidden arm stamps in nightclubs to show up!
This got me thinking. What if monomorphic finches were actually viewing each other in ultraviolet? Having worked with computer graphics for years I was very comfortable with using graphics software programs like Adobe Photoshop.
Using Photoshop I imported some pictures of monomorphic finches and began to apply different filters to mimic ultraviolet light. The first species I toyed with was a known pair of Diamond Firetails. I wanted to use a picture of a known breeding pair to see if I could see any visual differences when subjected to the colour filters. It was when I viewed the image as a negative that something jumped out at me! I saw a difference in the sexes so obvious that I couldn’t believe it had never been picked up before.
Here is what I found. The Diamond cock bird has a break in his black chest band where it meets the wing. The hen on the other hand has a smooth line right down the side of her body. So in the male, it is like a semi-circle cut out leaving a white patch. See images below.
Here is what I believe is a hen and a cock bird:
Within a couple of days of this discovery I visited 2 well known breeders and put my method to the test using their Diamonds.
I got 6 out of 6 correct!
It is still too early to say whether this is an absolute method of sexing Diamonds, but it is certainly looking promising. Therefore I would like to conduct an experiment. Any aviculturists who have known breeding pairs of Diamonds go and check your birds and see if my method holds true. Next, show someone (who does not know the sexes of your birds) this article and see if they can correctly sex them using my method.
It would be great if you could then report your findings back to me. We could then tally the score and see if this new method works.
This new method could help fix an age old problem with accurately sexing Diamonds! I have been looking at as many Diamond pictures as I can find and believe I can now sex these birds as quickly and accurately as if I was looking at Zebra finches!
I hope this helps anyone who has found sexing these finches difficult. Who knows, with more tinkering with colour filters I may unlock some more mysteries!
Good Breeding!
Danny
Postscript
Since this article was published in September 2010, 27 Diamond breeders returned results to me.
The scores using my method were as follows:
Young birds not fully coloured into adult plumage = 94.7%
Adult birds = 85%
by Danny Searle
It is a well know fact that birds see in perfect colour vision. With this in mind I have often wondered why many finch species are “Monomorphic”.
Monomorphic refers to those species where the sexes appear identical. If they see in colour, why then would the cocks look like hens? I then remembered that many birds, like Budgerigars can also see in Ultraviolet. Ultraviolet is a wavelength too high for humans to see. Ultraviolet lights are sometimes referred to as “black lights”. They make white shirts and teeth glow, and hidden arm stamps in nightclubs to show up!
This got me thinking. What if monomorphic finches were actually viewing each other in ultraviolet? Having worked with computer graphics for years I was very comfortable with using graphics software programs like Adobe Photoshop.
Using Photoshop I imported some pictures of monomorphic finches and began to apply different filters to mimic ultraviolet light. The first species I toyed with was a known pair of Diamond Firetails. I wanted to use a picture of a known breeding pair to see if I could see any visual differences when subjected to the colour filters. It was when I viewed the image as a negative that something jumped out at me! I saw a difference in the sexes so obvious that I couldn’t believe it had never been picked up before.
Here is what I found. The Diamond cock bird has a break in his black chest band where it meets the wing. The hen on the other hand has a smooth line right down the side of her body. So in the male, it is like a semi-circle cut out leaving a white patch. See images below.
Here is what I believe is a hen and a cock bird:
Within a couple of days of this discovery I visited 2 well known breeders and put my method to the test using their Diamonds.
I got 6 out of 6 correct!
It is still too early to say whether this is an absolute method of sexing Diamonds, but it is certainly looking promising. Therefore I would like to conduct an experiment. Any aviculturists who have known breeding pairs of Diamonds go and check your birds and see if my method holds true. Next, show someone (who does not know the sexes of your birds) this article and see if they can correctly sex them using my method.
It would be great if you could then report your findings back to me. We could then tally the score and see if this new method works.
This new method could help fix an age old problem with accurately sexing Diamonds! I have been looking at as many Diamond pictures as I can find and believe I can now sex these birds as quickly and accurately as if I was looking at Zebra finches!
I hope this helps anyone who has found sexing these finches difficult. Who knows, with more tinkering with colour filters I may unlock some more mysteries!
Good Breeding!
Danny
Postscript
Since this article was published in September 2010, 27 Diamond breeders returned results to me.
The scores using my method were as follows:
Young birds not fully coloured into adult plumage = 94.7%
Adult birds = 85%