If you think the air is clean in NM you should look at the map I linked to in #23. Keep a couple of things in mind. The smoke may be aloft not at ground level and migratory birds didn’t start out in NM.
Both of those reasons, smoke aloft and a long flight, might account for the fact that only migratory birds have been dying and local birds have not.
It has been sprinkling a LOT at my place for the last week, so my air is comparatively clean, and my predominate winds have been almost directly from the south.
Maybe there is lots of smoke above the cloud level here, My nose is pretty sensitive to smoke... I catch an occasional whiff, but mostly I blame it on the campground a mile away. Lots of Deer & Elk hunters out... But I have been surprised at how little there is. Quien Sabe.