Problem with edges of transparent textures

I impose transparent texture on an object, but the render of Flamingo as though can’t execute the correct transparency. At edges there are white scraps (incomplete transparency) though on texture there are no white obravk. Help, please!

Really in rendering Flamingo there are no usual masks? White (to leave), black (to remove) or on the contrary.

If to do so, then it turns out almost perfectly (edges a little rough).