Do you know of any signs mounted on those metal posts that have holes all down the middle? If the sign isn’t fastened in the top holes, they remain exposed and have been found to trap raptors, which get their toes stuck in the holes. I was provided with this photo by the USFWS of an unfortunate Great Horned Owl that met this fate. The inset shows the easy solution: bolts in the empty holes.
So be on the lookout for these perforated metal posts (also used for fencing) and let the owners know they are a hazard, and how to correct it.