In my case I am working in a camp where hundreds of kids can be present. I evaluate each snag (and tree) for hazards and also for a target. If there is a possible target, and area where people or property can be, then the tree comes down. We also are not snag poor. This means I try to retain 2 snags per acre if at all possible and more is even better. In the redwood and fir areas there are not a lot of birds so nests are infrequent. Deer don't seem to nest in trees, at least in California.
I'm looking for a source for "wildlife tree" tags, usually a yellow diamond. If anyone knows a vendor please post it here.
We suffered a major wind event a few weeks ago that damaged trees all over the county. One property I work on is owned by an artist so he made his own tags. He did a great job on them.