Like Flying Squirrels, Or Space Shuttles, Or Something, But With Faster Decision-Making

I especially like some of these BASE jumping videos where the fliers somersault in midair, just to show they can!

Here, in the video above, there are endless close brushes with terrain.

Wind flow distorts as it moves past terrain - accelerating near the terrain in a sort of Bernoulli effect. They must be taking advantage of that acceleration, somehow. Faster wind speeds will help keep you aloft longer, if you fly into the wind. Otherwise, I see no great advantage to passing within a few feet of trees (besides getting the best camera footage ever).

These ravines! OMG! Have to think FAST! One error, and you're finished! And what if you collide with a pigeon? Or even a dragonfly?

Such decision-making. In the next video, the flyer decides to go right, instead of straight. If it was me, I'd probably go straight, and belly-flop right into the terrain feature. So, how did the flyer decide, and when?