In May of this year, about 90 volunteers with Tucson Audubon Society spent around 500 hours surveying five mountain ranges in southeastern Arizona over three weekends. Their goal: to count Elegant Trogons in the only region in the U.S. where the species nests.
They tallied only 68 trogons, about two-thirds of the 201 birds found in 2020. In nine years of surveys, it was by far the smallest trogon count.
Jennie MacFarland, Tucson Audubon’s bird conservation biologist who coordinates the trogon surveys, told the Arizona Daily Star the decline is the result of an extreme drought gripping southern Arizona. The 18-month period through May was the driest period of that length on record at the Tucson airport, according to National Weather Service records.
“Trogons need a lot of insects to raise their young. It’s so dry out there, I don’t think it looks good for them, including to nest,” MacFarland said.
The newspaper continued:
A small number of Southern Arizona trogons live here year-round, but the vast majority migrate back and forth from Sonora while breeding in this country.
“Most would have had to come up here to nest. Either they found the journey too difficult, since there’s a drought in Mexico too, so I think a lot of them just stayed,” MacFarland said.
“Some may have died, but I suspect not. Migrants sort of figure this stuff out,” MacFarland added. “When they start traveling and run into conditions that don’t seem safe, I think a lot of them just turn around and go back.”
In a follow-up article, climate scientists disagreed about whether a firm link can be established between a one-year decline in trogons, a region-wide drought, and the climate crisis.
Nonetheless, said Rick Taylor, a trogon researcher, southern Arizona naturalist, and field-guide author: “You shouldn’t see such radical population swings; you should not see this in trogons, all things being equal.”
A version of this article appears in “Birding Briefs” in the September/October 2021 issue of BirdWatching magazine.