There were several good inherent ideas for wood-elves and I'm sure the immortals (being all knowing, seeing and so on) have already pondered this but I thought I'd bring it up all the same.

Why not throw the elves a 'Nature affinity' inherent that has a chance of firing off when certain things in their environment change unnaturally.

Within forests, things like the weather being changed via magic or commune. Tainting of their surroundings would also be sensed at a distance as the life around them may react in a way they sense well. Also, people like necromancers who bring undead into the wilderness may cause alarm amongst the wildlife that the wood-elf can pick up.

Without making it too precise, their affinity for nature could pick on a few types of changes and help the wood-elf recognise that something is wrong in a subtle way that makes them look around. I'm not saying an echo like:
'Mr.bob enters the area, the very forest around you crying in alarm.'

More like:
'Sensing the unnease about you, the hair on your neck stands on end.'

That way it could be anything from an unnatural manipulation of the weather to the entrance of an orc or something equally vile and disturbing to nature. Think, add, whatever. Just trying to spark the imagination...


Me.