We found a highly unlikely bird last month during the Christmas Bird Count at Cantigny -- a Nashville warbler. The species migrates through our region in the spring and early fall, and during those times it's pretty easy to spot one. But after October? Good luck with that.
So what was a Nashville warbler doing here on Dec. 19? And what about the painted bunting that caused a media sensation in New York City, also in December?
The knee-jerk response to these questions might be two words: climate change. Or an even better guess: El Nino. But cases of misplaced birds are nothing new. Storms and strong winds are often to blame, or sometimes a bird's internal compass just goes haywire. Birds get lost.
That said, warmer conditions may cause a wayward bird to stay put in the same place for days or weeks, assuming it locates a food source. It learns to adjust.
Indeed, the ability of birds to adapt to new environmental conditions is one of their key strengths. That's the good news. The bad news is that global warming in the decades ahead will test their resourcefulness like never before.
In November I went to hear a talk about the effects of climate change on birds in the Chicago region. The speaker was Doug Stotz, a conservation ecologist and ornithologist at the Field Museum in Chicago. He's also the co-chairman of the Chicago Wilderness Climate Change Task Force.
"The great thing about climate change is that it makes our winters warmer," Stotz said. "It's hard, as a Chicagoan, not to think that's a good idea."
Yes, I think we could all agree that ditching the down-filled parkas and flannel-lined jeans would be OK. And what birder around here would not enjoy some traditionally southern or southwest species moving into our region as average temperatures climb?
We know it's wrong, but it's hard to stop visions of painted buntings and scissor-tailed flycatchers from dancing in our heads. A few southern beauties are already here.
"Blue grosbeak, summer tanager and yellow-throated warbler are birds that didn't use to breed in the Chicago area, but they do now," Stotz said.
But whatever advantages climate change may hold for shivering Chicagoans and thrill-seeking birders, Stotz made one thing perfectly clear: Global warming is not good for most birds. The science tells us so.
In 2014, the National Audubon Society unveiled a seven-year study on the predicted impact of climate change on North American bird populations. Out of 588 species studied, 314 were deemed at risk from global warming by 2080. For many, according to Audubon's climate model, the "gathering storm" will come sooner. To survive, the birds must adapt to losing huge portions of their current living areas.
Stotz cited the bobolink, a grassland species that even now struggles to prosper in the Chicago region. Climate change is shifting the bird's range northward. By 2050, he said, "Bobolinks are going to be in what is now boreal forest. It seems unlikely that will work."
Of the 314 at-risk species identified by Audubon, 126 are classified as "climate endangered," meaning they are projected to lose more than 50 percent of their current range by 2050 if global warming continues at its current pace.
Even common birds not listed in the Audubon study could vanish from our region due to climatic stress. The black-capped chickadee, Stotz said, could vacate Illinois, moving north as temperatures rise.
Avian visitors we look forward to seeing only in winter may no longer "drop down." If you are lucky enough to see a redpoll, a crossbill or northern shrike this winter, savor the experience. Spotting these and other species in the Chicago region may become significantly more challenging.
Sorry, that's the birder in me coming out again. Climate change is not about birding, of course. It's about the gradual disruption of ecosystems and all the flora and fauna that depend on those systems being in balance.
The global climate talks in Paris last month yielded a glimmer of optimism. We'll see.
"It's easy to feel overwhelmed," Audubon's President and CEO David Yarnold wrote more than a year ago, and I'll bet he feels the same way today. Don't we all?
For those who study birds, there is hope. Through effective habitat management, Stotz thinks the bobolink and other vulnerable species can be saved.
"One of the big things we can do to fight climate change is to get our natural areas into the best condition possible," he said. "There is no question that birds in a healthy environment can hold on in the face of climate change much better than if they are already stressed."
To learn more about birds and climate change, visit climate.audubon.org. The site includes ideas for helping birds and ways we can all respond to the biggest conservation challenge of our time.
• Jeff Reiter's column appears monthly in the Daily Herald. You can reach him via his blog, Words on Birds.