The answer to your last line “Has anyone ever heard of this?” is (as I think you know), a certain YES. The same thing happened to a raven chick in my yard a few years ago but these are just single stories. But as you say “This nasty story is apparently not uncommon.” It is a problem for many nesting birds, that may use string and plastic in building or lining nests. These are often long and tangled or just unbreakable, such as plastic rings. The animals once entangled, can rarely escape. When caught up on growing bodies, the effects can be horrible. Similar problems are prominent for marine animals. I recall having seen film of a marine turtle that had got a plastic ring around its body between its front and rear legs (obviously when little) and continued to grow probably for many years and was very deformed with its middle constricted and probably suffering terribly, until found that way. I don’t recall if it was found alive or dead. People should cut all plastic rings, so they will open, before chucking, for that reason, so that it can slip off an animal.
Philip
