Our chooks have never grabbed up any, but our Slate turkey hen (when still a `little' jenny) scarfed a visitor's -dragged-out, but still lit, butt snatching it from between her fingers! Scurrying away trailing tiny red embers!
I'm in my 50's and, back in the day (here it comes) HS biology included a demonstration of the `dangers' of smoking/nicotine by the teacher smoking an unfiltered Lucky Strike through a folded kleenex. The teacher crushed the butt, tore the nicotine/tar stained patch out of the kleenex and stuffed it into an underdeveloped bullfrog's mouth.
Everyone in class stared at the now poisoned amphibian. Sure enough, it started to `tighten' up, tremble and then seize. it then stretched out rolled over on one side and died (took about ten minutes and everyone was pretty much transfixed by the frog's agonies and ignored the teacher's continued lecturing).
After class, fellow classmates, who had picked up the filthy habit already, `hopped' to it to get behind the gym because the demonstration left them needing a smoke `real bad'
We were kinda `smokin'' ourselves, a sight more than a bit miffed... But, the hen remained symptom free, though her breath smelled like an ashtray for three days (slight burn on her tongue). Anyone who comes over and wants to smoke has to walk all the way down to the road and then `field strip' the butt...
I think the fact that the nicotine from a single cigarette butt enters the bloodstream of a large enough chook/turk more slowly than amphibians/mammals (crop/gizzard acting like dose metering devices) might keep them from the drooling pukes and twitching. If the dose is high enough nicotine replaces the acetylcholine at neuromuscular receptor sites and, given a substantial enough dose, both a chook and a human's nervous system are `shorted' and death follows quickly.
Don't worry too much, cigs will be taxed out of the legal market real soon now.