What started out as a simple fix has turned into a pretty great update. Now when the Birds get a down trace hit they get vertical thrust as well as a variable pitch adjustment.
This behavior piggybacks on top of the trace we were already doing, so this enhanced behavior comes without any additional processing cost.
This new behavior is also very modifiable, you can change the draw distance and vertical thrust amount to fit any environmental condition. Just be sure that you place your Sky Targets higher than your Birds avoidance draw distance.
I will submit this update next week, in the mean time here is a quick video showing Birds v2.5 in action 
watch?v=wWCy572f50I