Last year, I was involved with a project to use color bands on Purple Martins to help learn, among other things, about some of their migration habits. The bands are easier to read than the standard USFWS silver bands, though those are still applied as well. Here are a few pictures from a recent banding session. The egg pictured here did not hatch and was removed from the nest box/tray. See how small they are? The next photo shows Mark Newstrom banding one of the chicks. It is a very delicate process (I know - I got to do 30 or so of them this year!) - you have to be careful of their fragile feathers, and their legs.