Something Bird Watchers Do Sometimes

Something bird watchers do sometimes is put little metal bands around birds' legs. They use them to track migratory patterns, among other things, and maybe you already knew that, but did you know how they do it?
They trap the them. In nets. The birds.
If you're just finding out for the first time, as I was a few weeks ago, you might be thinking something like 'huh' or 'LOL WUT', but apparently it's totally okay. They catch the birds in nets, and then put them in bags, and then take a bunch of measurements, and then set them free. And it's fine with the birds- well, if not with the caught birds, with the bird population as a whole, I guess.

Anyway, the nets are these long ones, called 'mist nets', that they set up in a few different places wherever they are tagging birds. In El Jaguar they were mostly set up on the edge of the cloud forest.

After removing the birds from the mist nets, bird-banders take them to their base-camp table and take a slew of measurements that tell them all kinds of things. They record everything, and send all of their data to some database somewhere. If a bird bander catches a bird that has already been banded the 2 sets of data can confirm and suggest theories about migration patterns.

One of the things that's cool about the process is how well you actually get to see (and photograph) the birds. You can even hold them, and set them free (somebody has to).