I had a tortoise that died from eating a castor bean seed(s). It was a horrible thing to watch.
A turtle won't show signs of poisoning (or many other illnesses, for that matter) for quite a while, in part because they have such slow metabolisms. But once the poison is in the system, it's doing its damage, and by the time you notice that something is wrong, there is nothing you can do. So he died a very slow and miserable death, stretched over some weeks, all because I had to have the lovely castor bean plant (which stays alive all winter here in Houston) out along the side of the house, and some of the seeds fell into the yard where the tortoise was.
Joyce, how do you grow those pitcher plants? Are they in water, bog, soil, or what?