A friend of mine found this website that lists several toxic plants, & their symptoms, along with some non-toxic plants. As is mentioned on this site, it all depends upon the amount the bird eats & how healthy it is on how severe it's symptoms are. Hope you guys find this as useful as I have.
http://www.peteducation.com/article.cfm?c=15+1912&aid=2236

http://www.peteducation.com/article.cfm?c=15+1912&aid=2236