I just compared our August 2021 records with those for the last 3 years.
This year we saw no Western Bluebirds, and only a few Mountain Bluebirds. Also only a few Tree Swallows; in 2018 we had lots of swallows of several races, though not in then next two years.
Another species that has declined - believe it or not -- Red-winged Blackbird!
A rather odd August, I think.
Hugh