Superbowl

I believe it is mostly done on wild birds, though there does seem to be some use for it on captive animals potentially as well.

By providing a tracking number to each bird caught, scientists can then see what happens to each one and work with that data. They can see the path of migration, determine how long they spend at each stop or how many stops they make, how long they live, and much more.

There are colored bands available as well, so individuals can be quickly identified. This is one possible use I can think of in captivity, probably not so much with raptors since they are solitary animals, but with other species.

There are other types of bands available for other birds types. Geese have feet that will be under water the majority of their observation time, so they have neck bands. Other larger raptors can also have wing tags. I saw some of these on some migrating vultures the other week.

Everything I've looked at has the bird in the handlers hand during banding. They probably want to have maximum control while using the pliers so the birds makes less uncontrolled movements to prevent injury.

For banding, the goal seems to be to release the birds quickly with the least disturbed to them while still being safe, so I don't think the an apparatus is used too much. Most things seem to be done in the field rather than inside like this. I think the Saw Whet Owl being so small may let them do this so they can work with multiple birds in quick succession. The Barn Owl and Great Horned Owl videos I watched seems to make it look like a 2 person job for some of the larger owls.

They do wrap up owls often too weigh them so they sit still on the scale where having a hold on them would impact the measurement.

I haven't banded myself, it looks like you need a federal license. I'm going to an event this weekend that will hopefully have some owl banding, so I can ask them any questions I might not be able to find answers to.