As a birdwatcher I strongly expect the benefit is in the identification experience and agree with this sibling comment:

> A big part of birdwatching is identifying small, fast-moving animals that exhibit specific combinations of behaviors at specific times of the year based on specific climatic conditions. That sort of rapidfire pattern matching from video and audio info is probably a big contributor to what keeps the brain sharp.

It takes time and experience to build up your identification skills but it’s really rewarding and exciting and modern tech makes it easier than ever to learn