Yavanna's Chosen

[Pitchwife]

Among other tasks, I'm pretty sure Radagast's activities included furthering higher education among foxes, qualifying them to observe Hobbit behaviour patterns and comment on irregularities therein.
More seriously -

Originally Posted by Legate

Last but not least, I think Radagast could have been there to give the Istari's mission "ecological" aspect. I.e. prevent that, for example, Saruman would not come and say "Oh, I know how to defeat Sauron! Let's build ten thousand factories and forge unbeatable weapons." Radagast's vocation would have been probably to correct his course at that point.

This sounds very plausible, except that he didn't - in other words, if such was his mission, he failed bigtime. I really don't understand why Radagast apparently trusted Saruman so long. All that tree-felling, burning and smeltering in and around Isengard should have outraged him - but in the short dialogue scene reported by Gandalf at the Council of Elrond, which seems to imply that Radagast had come straight from Orthanc looking for Gandalf, there's no hint of anything of the sort. So, are we to suppose that the whole industrialization of Isengard, including the breeding and armament of a huge army of Uruks, was done in the following months, with no preparations visible at the time of Radagast's last visit, or did he tell himself, "Well, I don't like at all what Saruman is doing there, but he's the head of the Order, so I won't question him?" If the latter, he really was the simpleton Saruman took him for, much as I'd prefer to think there was a little more to him.