I am having a real issue with hunting this bird down, and i'm actually beginning to think my game may have possible glitched.
I found the bird more-or-less straight away but then it flew away. I've hunted high and low for it, day and night and I cannot find it anywhere. I've looked in all the places that have been mentioned in other answers but still got nothing.
Has this happened to anybody else? Does it go anywhere in Soviet Instillation or just around the main 'mill' area?