Well written and the pictures are fine. I doubt that Oswald convinced anyone that he could climb that tree. Here I had a flock of game cross bantams that roosted in the white pine trees for years. Until, that is, the GHO found them.
Excellent observations, conclusions, and pictures. Ants and birds - I have seen birds dust/sunbathe in ant hills with wings outspread. Perhaps a combination of formic acid from the ants as well as parasite removal help to limit external parasites.