Can't see the orcs being too terrified by herds of rampaging deer, but birds could have been useful for scouting the area, (eg Roac and Carc and the Crebain). Perhaps Radagast even found an eagle or two to assist.
Interesting point about the use of power by the Istari, which was restricted by the Valar. Maybe they got away with it by assisting Galadriel, rather than doing everything themselves. Certainly some uses of 'magic' or 'power' were allowable, eg. Gandalf's Nazgul-repelling 'bolts'. The main thing was not to unleash excessive power, so presumably Gandalf (and Saruman?) had to limit the assistance they could give.
Found those previous threads at last, they were lurking in Haudh-en-Ndegin
White Council
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Attack on Dol Guldur
[ July 07, 2003: Message edited by: Rumil ]