The only way to determine the gender of an African Grey is to check its DNA. What part do they take? A scraping, a feather or blood?
They can either do it with a blood sample or with feathers (freshly plucked by you). You will need a minimum of 5 feathers.
Try this website:
http://www.avianbiotech.com/SexingCenter.htm
Goodluck! 
When mine had it done they used blood from his toe nail but I also had him tested for diseases too at the same time, so I could have him boarded.
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It’s a boy!
this is the first time i hear about that , I had one long time ago and it was male , back then there was no such DNA , so how did the found out , there must be another way!! like any bird?
http://www.ehow.com/how_2120789_determine-gender-african-grey-parrots.html?ref=fuel
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They can either do it with a blood sample or with feathers (freshly plucked by you). You will need a minimum of 5 feathers.
Try this website:
http://www.avianbiotech.com/SexingCenter.htm
Goodluck!
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ask your avian vet and mine had pulled three feathers and put them into a vial and sent them to california for the test,, the liquid from a fresly pulled feather is at the shaft. and in three weeks i had a male grey good luck :>
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feathers or blood from toenail but i don’t like that because mine cries when he got his blood taken he was so sad:(
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Whoever told you that lied to you. Greys can be surgically sexed, just like every other bird. If you decide to have a DNA sexing done (takes longer, costs more, but is very slightly safer for the bird) they take a few feathers
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Owner of 2 parrots (one’s a Grey)
DNA testing is very simple, quick and cheap. ($20 for blood, $25 for feather) All you need to do is clip a nail short for a few drops of blood on a test card, or to pluck a few chest feathers and send it in. You usually can have results emailed to you in just a few days, with a certification card coming in the mail a few days later.
I personally prefer the feather method to blood or having my birds surgically sexed. Hurts them less than clipping the nail short enough to bleed (hurts you like heck when you get a nail short enough to bleed doesnt it? as opposed to a quick pull of a few hairs on your head?) and is usually cheaper and much less invasive than surgically sexing ( which has to be done by a certified avian vet).
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Own and breed various species of birds