Sunday, September 20th 2020, 2:05 pm - Smoke from the wildfires could have harmed the birds or prompted them to begin their migrations before they were ready, though a recent cold snap is also one potential culprit.
Thousands of migratory birds, possibly more than a million by some estimates, have been found dead across parts of the western U.S., and the poor air quality from ongoing wildfires is one possible cause.
A large number of dead birds were first discovered in late August in New Mexico, but since then, more have been discovered in various parts of that state and some of its neighbours.
"It's devastating. I don't think I've ever seen anything this horrible in my life," Prof. Martha Desmond, at the University of New Mexico's department of fish, wildlife, and conservation ecology, told media.
Mountain bluebird. Credit: Elaine R. Wilson/Wikipedia
Desmond says the number of birds that have died may be "in the millions."
The dead birds include warblers, bluebirds, sparrows, blackbirds, the western wood pewee and flycatchers, according to CNN, which reports they have also been found in Colorado, Texas and Mexico, and many were seen behaving strangely before being found dead.
Smoke from the ongoing western wildfires is a potential culprit, having an effect on the birds' lungs and possibly moving them to start their migrations early, before they had built up enough fat to sustain them on the journey. A rapid cold snap that brought early snows to come areas may also have caught them unprepared.
However, Desmond says the ultimate cause of the widespread deaths won't be known until the carcasses can be studied in detail.