Concerning Istaris

[obloquy]

as animals, birds and plants mattered much for Yavanna and Elves as well, shouldn't there be at least one to care for them and make use of them inthe oncoming struggle.

This may have been Yavanna's purpose in pushing for Aiwendil's inclusion, but it was not his official mission. From Unfinished Tales we read:

For Radagast, the fourth, became enamoured of the many beasts and birds that dwelt in Middle-earth, and forsook Elves and Men, and spent his days among the wild creatures.

Apparently his purpose was originally the same as the others: to aid Elves and Men in the struggle against Sauron.

Edit: Hopefully this will update my avatar URL.

[ June 21, 2002: Message edited by: obloquy ]