It’s birdwatching season, and climate change is sending birds much earlier
The pandemic made birdwatching more popular, but the timelines are shifting on when some of the most cherished birds arrive.By Michael Gerstein
On a crisp recent afternoon at Montrose Point Bird Sanctuary, Marian Runk, a 41-year-old illustrator, folk singer and Avondale resident, searched for whatever was out, her binoculars in hand.
Runk, whose father passed on the hobby, has been birdwatching for 15 years. She hoped to see an early yellow warbler. But like many birders, she was happy to see anything that flutters.
“I converted him a few years ago,” she said, pointing to her birdwatching accomplice, Andrew Wilkins, 41.
But some of the birds Runk was most eager to spot — like that yellow warbler — are visiting the region earlier as the planet continues to warm. That’s according to a new study from bird researchers at the Field Museum in Chicago and other experts published in late March in the Journal of Animal Ecology. It confirms what past research has shown and offers more insight into how climate change is impacting animal biology on Earth, experts say.
At Montrose Harbor on this particular day, many people were new to birdwatching and said they took it up for the first time during the COVID-19 pandemic. Kyoji Nakano, who is in his 70s, said he started birding during the pandemic because he didn’t have much else to do and needed a reason to get some exercise. He has viewed hawks in summer, and a white snow owl in winter, but his favorite thing to do is feed peanuts to the chickadees. “They eat it in your hands,” he said.
Among the early spring arrivals were red-winged blackbirds who were singing their signature, gurgling, conk-la-ree in the trees near the turquoise water, as gulls flew overhead and ducks waddled in the moist grass looking for scraps and grubs.Blackbirds are among the species traveling through the region earlier — by about 11 days to be exact — compared to 150 years ago. Among 72 species for which scientists could gather data, roughly one-third are laying the first spring eggs about 25 days earlier than a century-and-a-half ago.
It’s just one “small piece of the puzzle” of how climate change is impacting avian life, said John Bates, the Field Museum’s bird curator and the study’s lead author.
What’s unique about the study is how Bates and other researchers paired the museum’s egg collection dating as far back as the 1920s with more recent observations on a different topic – brown-headed cowbirds and how they pass off parenting by laying their eggs in other birds’ nests for those species to raise – to conclude that many different varieties are migrating to Chicago much earlier than before.
The museum’s egg collection ends after the 1920s, when egg collecting became rarer, but the cowbird research, from a fellow Field Museum scientist named Bill Strausberger, opened the door for the spring migration study.
“The amateurs that collected most of these egg sets back in the 1880s to 1920s had no idea how they would be used in 2020,” Bates said. “That’s an interesting thing about data. From the modern side, the data that we used for the paper was the result of work these guys were doing on completely different research projects.”
Because meteorological records don’t go back that far, the researchers used carbon dioxide data from ice core samples as a proxy for rising temperatures.
The earlier egg-laying and migration dates haven’t been linear. But going back far enough, the trend is obvious. Some birds such as the American kestrel — another prized species among birders to sight — are laying eggs as many as 50 days earlier than in 1872, according to the study.
Most surprising, Bates said, was learning that even long-distance migrants that must fly north from as far as South America are coming much earlier. In the case of the yellow-billed cuckoo, they’re laying eggs about 37 days earlier than 150 years ago. For the yellow warbler, it’s 23 days earlier.
How could birds like the yellow-billed cuckoo and warblers wintering in the tropics know it’s warm enough to lay eggs in Chicago in June, instead of July a century ago? Most likely, Bates said, they fly to southern U.S. states first and then north in sync with favorable conditions, looking for soft-bodied insects and good places to breed.
Although other studies show the trend that the Field Museum study demonstrated, “few, if any, go back this far,” said Andrew Farnsworth, a senior researcher at the Cornell Lab of Ornithology, which runs the popular and information-packed website eBird, a key resource for many birders.
“The more information we can put behind the notion of how much climate has changed and what that means for the biological organisms and, writ large, ecosystems in general — connecting the dots — that’s always good,” Farnsworth said.
Good historical data about bird migration and nesting is scarce, Farnsworth said.For many longtime Chicago birders, it also confirms what some have noticed over a lifetime of watching spring migration, said Judy Pollock, president of the Chicago Audubon Society.
For example, Pollock said Chicago birders recently posted pictures of towhees in the area, a striking black, brown and yellow kind of sparrow. They have a call that sounds like “drink your tea,” Pollock said. And they don’t normally come this early, she said.
But for birders in the Chicago region and much of the Midwest, springtime is about the warblers. Thirty-six different kinds migrate north to Chicago from the tropics, some flying from as far as South America to grace bird enthusiasts with their bright, colorful feathers and exuberant songs.
Chicago is crucial for bird conservationists and for hundreds of species that nest here or fly through the city on their way north.
It’s also home to a wide array of local bird clubs, from chapters of feminist clubs to clubs specifically for people of color and Indigenous birders. Prime birdwatching destinations such as the Chicago Botanic Garden, Montrose Point, Humboldt Park, Washington Park and Jackson Park are all great spots to see the birds, too, according to the Chicago Audubon Society.
“A lot of people don’t realize that a city like Chicago can be really important for birds,” Pollock said. Migrating land birds come up through the middle of the country, with many drawn in by the lake and the city’s bright lights.
Among the birding hotspots, Montrose Point will always be a favorite. For many Chicagoans, it was the first park they started, Pollock said. It was also the home of a pair of piping plovers, Monty and Rose, which got a lot of attention in 2019 and 2020.
Montrose Harbor is where Matthew Dolkart, a 37-year-old Andersonville resident, first started searching.
“It’s amazing what you see when you get outside and start looking for it,” Dolkart said. He also got into birdwatching during the pandemic, but you wouldn’t know he’s new to the hobby by talking to him. He has learned a lot in a year-and-a-half.
“I had no idea that in one year I could see 250 different species of birds, or 225 different species of birds just at Montrose,” Dolkart said. “So spending a year just in appreciation of nature and everything that we have within this city — I think it’s been a really valuable lesson for me to appreciate even just the small little nooks that we have in the city and what it supports.”
Plus, Dolkart said, it’s just great to get outside. You never know what might show up.
Michael Gerstein is a freelance writer based in Chicago.
Have a question? Send it to email@example.com, and we’ll ask the experts. Include a voice memo with your name, location and question, and you could be featured on the radio!
See ongoing stories from WBEZ and the Local Media Association, and listen to interviews with experts about climate change topics in our region.