Hello... fyi - i copied this information from the canadian page. user jwnix was kind enough to post...
ps - first time creating a new topic - hope i did it correctly...
here is some information from Dr Peter Sharpe re: wing markers :
May 7, 2006
The wing markers are treated like feathers by the birds and we have seen no evidence that they have impacted the birds at all in the 17 years that we have used them. The birds do get leg bands, but those can only be read from about 50 m away with a powerful spotting scope and if the bird is standing just right. Because this is a managed population of bald eagles that would not exist without our help, it is important for us to know who each bird is and to get an idea of where they are taking up residence if they leave the island. The wing markers do eventually break down and fall off the birds.
The wing markers are made of a vinyl covered polyester called Shelterite. They are very light and are folded over the front of the wing and attached through the patagium with a small stud usually used for putting eartags on piglets. There are few nerves and blood vessels in the patagium, so the attachment is quick and painless.
Peter B. Sharpe