Mist nets are typically made of nylon or polyester mesh suspended between two poles, resembling a volleyball net. When properly deployed in the correct habitat, the nets are virtually invisible. Mist nets have shelves created by horizontally strung lines that create a loose, baggy pocket. When a bird or bat hits the net, it falls into this pocket, where it becomes tangled.
How do they catch them for banding?
In this post there is a bit about catching them with nets. I think this is the same project, but I might be mistaken
Thank you for linking this!
Wiki: Mist Nets full article