I've had big problems with zip ties. I put one on my adult peahen because she kept getting into the neighbors garden & I had trouble picking her out from all of theirs. It was cut really close to the fat part so nothing could tighten it but it still happened somehow. I went away for a few weeks & when I collected her from my friend, the zip was so tight, it was cutting into her & she could hardly walk. I was horrified & cut it off but it took a long time to heal.
I've been doing this for 4 years now and have had no problems. I use colored one's because that tells me who is kin to who! It also tells me when they were born and if they are male or female(on young ducks mostly). I put a different color on each years hatch and I put ties on the left (looking at them from the front) for females and on the right for males. Chickens get colored for the hatch......and when the next hatch of the year comes ties get put on the opp. leg but, with the same color. You can do it which ever way works best for you. The really good thing is that you can tell who is who and what is what from a distance!
I put zip ties on my adult turkey hens last week, and so far so good. Although I left the ties fairly loose, they slipped down around their "ankles". They don't seem to mind them at all, but I'm going to keep a close eye on them to make sure they don't pinch or get too tight or anything. I'm assuming adult hens are not going to grow anymore.