First, I'd like to say that it's clear that we all share a deep concern for the welfare of the wildlife we love and photograph! This is the wonderful common thread to this discussion and it is much appreciated! I think we all share the same goal, which is that we want the birds (and other wildlife) to live high quality lives. And to thrive.
My limited experience with banding is that it is done humanely, carefully, gently with very few if any injuries, and there is an important demonstrated purpose that has oversight. That purpose is guided by conservation needs and science. My goal is to help that conservation.
There are significant benefits that I can think of. One local example is understanding where CA's endangered Tricolored Blackbirds breed, migrate to, and what kind of habitat they need. Studying them (for decades) has led to programs where farmers are paid to NOT cut fields where colonies are breeding, saving many, many 1000s of baby birds from being ground up in harvesters, a fate worse than the discomfort of banding. Banding played an important part in understanding how these iconic birds move around the state, and still does.
https://ca.audubon.org/birds-0/tricolored-blackbird-0, and
https://tricolor.ice.ucdavis.edu/research-and-monitoring
But I thoroughly understand people's concerns! Your concerns are very well intentioned and appreciated, I share them. Banding may not always be done in the way I have experienced, especially where there is less oversight. I for one feel that I need to trust the oversight process here in the US.
To me, the disturbance the birds experience is an unfortunate but necessary compromise in our collective efforts to help save wildlife. There are far greater threats such as wholesale habitat destruction that impact the wildlife we love. But the work must be done with consistent, humane standards.
I've been thinking about starting a thread asking how others might be using their photography to help protect what we all love. I know there are many professionals here, but also many amateurs (like me). I started to learn photography because I like the artistic side of it. But also because I wanted to learn and document the birds I'm observing in surveys and in citizen science (ebird and other venues). Also to document important endangered CA native plants so that their habitat can be protected
https://www.calflora.org/. It would be fun to hear what others are working on. I hope that someday my photos will consistently reach the level I'm seeing from this forum's members.
So on a positive note, I'd like to acknowledge that people have a legitimate right to expect this work to be done ethically and humanely. The public expressing that concern IS part of the oversight. Birders, scientists and photographers all should try to do their work responsibly.
I may be a new member, but the empathy and concern for wildlife I've read in all these comments makes me positive I didn't make a mistake in joining this forum. Sorry about being long-winded...
and Thanks!
-- Alan