Several years ago, biology professor Peter Scott would prepare his class to witness an impressive annual feat of nature firsthand, which they viewed from an Indiana State University parking lot.
He and his students gathered outside, braving the frigidity of the winter air before turning their attention to the heavens. As dusk approached, they’d take note of pepper-colored birds sprinkling the sky. It started with just a few … perhaps in a small group.
Then another. And another.
Soon the dotted sky darkened with the fluttering, flying birds flocking together as they settled back into town for the evening. Just as some humans flock to warmer climates during chilly desolate stretches, certain avian travelers commonly move to cities – including Terre Haute and the Indiana State campus – for a reprieve.
Tens of thousands of the raven-colored snowbirds Scott and his students witnessed are American crows. And come winter time, Indiana State’s hometown is their town.
Though a new phenomenon to some university students, it’s an annual event upperclassmen and alumni know well. Some might be intrigued by the gargantuan roost in the city, while others are perturbed by the nuisance: tens of thousands of birds descend into Terre Haute, where they fight, forage for food, and of course, perform bodily functions that leave no doubt there’s an influx of birds nearby.
The crows have been shooed and scattered, only to have them inevitably return. An animal control company contracted by Indiana State has honed in on the increasingly pesky nuisance. The university has also donated money to a local group working to minimize the birds’ communitywide impact.
Terre Haute’s annual crow roost is an event that’s part science, part civic issue and part local lore.
Scott’s class count, the last of which was conducted in 2009, helped create a broad estimate of crows roosting each year. He estimates that, during the last 15 years, between 35,000 and 65,000 crows roosted in Terre Haute at the peak of the season, which is December and January. The total varied from year to year, and his classes estimated based on simple counting.
“Mainly, I wanted students to think about the social behavior of bird species, and why crows have evolved this behavior of gathering together in the winter, in the non-breeding season, in huge numbers and roosting at night, as opposed to some other behavior,” Scott said. “Here they are, coming right over campus and into town by the tens of thousands, and amazingly enough, most students have never noticed it before. It’s never really dawned on them that there’s that many.”
Scientists are not exactly sure why crows migrate to cities. They used to flock in unpopulated wooded areas, Scott said, before they began migrating into cities sometime over the last century. Researchers believe that crows roosting together could provide safety from predators, cities are warmer than the countryside and the birds can’t be hunted in cities as they can in rural areas, Scott said.
“It’s very common for crows to roost in cities in the winter,” he said. “They usually just don’t do it in this big a number. We aren’t necessarily the biggest crow roosting site, though we are the biggest in the state.”
Students participating in one count several years ago were surprised at the number of birds flying into the city, said Jenny Bodwell, a master’s student from Canaan, N.H., who was a teaching assistant in Scott’s class during the count.
“The sky was darkened with crows. It was already dark out, but you couldn’t see any more of the pale dark blue sky,” Bodwell said. “It was all crows. They just kept streaming in from all directions.”
“Crows are awesome and they’re one of the smartest birds.” — Jenny Bodwell
The roosting crows do not bring many benefits. The nearly 50,000 birds flocking to the city each year eat waste grain from nearby agricultural fields, while in Terre Haute they could be eating insect larvae in the ground, road killed animals and trash, Scott said. Some people enjoy the impressive natural phenomenon of the roost, though that’s typically when the birds don’t roost on their property, he added.
While the crow roost is a nuisance, it does not pose a health risk to people, said Travella Myers, environmental health supervisor with the Vigo County Health Department. Some people may worry about histoplasmosis, a disease caused by a fungus that grows in areas contaminated with bird or bat droppings, according to a Centers for Disease Control website. But the disease requires years’ worth of bird droppings to accumulate and dry out, then be disturbed so that spores are released into the air, which is rare with crows, since their droppings are washed away by rain, Myers said. She added that the disease is more commonly attributed to birds that roost inside buildings, such as pigeons, and bats.
Still, the crows’ accumulated droppings could cause walkways to become slick, said Joy Sacopulos, a member of the Terre Haute Crow Committee, a nonprofit organization formed last year to deal with the crow roost.
“So maybe they’re not going to give you a disease, but how would you like a broken hip?” she said.
By the time the crows nestled into ISU, the university was already battling birds invading campus. About two decades ago, the university contracted a company to treat areas of the steam plant on campus to get rid of starlings and pigeons that infiltrated the plant.
Indiana State now has an annual contract with the company, which regularly patrols campus to ensure starlings and pigeons are not roosting in large numbers. About five years ago, crows began pestering the campus, said Jim Gregg, central heating plant and utilities manager at Indiana State.
“So maybe they’re not going to give you a disease, but how would you like a broken hip?” — Joy Sacopulos
“The big problem now is the crows, so they’ve kind of switched to fighting off the crows in the winter time, and they put a lot of effort into it,” Gregg said. “They spend a lot of time on campus chasing those crows off. Crows are very, very hard to get rid of.”
Last year, ISU spent about $70,000 on its contract with A-Mark Bird Management for bird control, Gregg said. The university also gave $5,000 to the Terre Haute Crow Committee to help with communitywide efforts. A-Mark Bird Management solely works on campus, though there is some coordination with the city’s crow committee, Gregg said.
At Indiana State and elsewhere in Terre Haute, people try to disperse the crows by launching pyrotechnics, or fireworks, along with laser lights and noise to startle them into fleeing from areas they’re not wanted. ISU does not kill birds as a population control measure.
“Crows are very good at recognizing patterns, so you have to mix up your patterns,” Gregg said. “Once they get used to something, it doesn’t bother them, so you really have to mix it up with crows.”
Though the crows have flocked to Terre Haute for years, the birds invaded downtown – and around ISU – harder than normal two years ago, which caused an atrocious mess, Scott said. He remembers that the damage led to more demands that a solution be proposed to rein in the roost.
A local committee was formed to deal with the crows. ISU’s Scott and Gregg, along with Sacopulos, were among the volunteers on the committee, which raised private donations, including money from Indiana State, to pay for supplies. The group also organized volunteers each night to travel Terre Haute and help disperse the crows from troublesome areas.
Members of different organizations, including ISU students and fraternities and sororities, volunteered to help scatter the unwanted birds.
“They wound up moving around and not causing too much damage to any one place,” Scott said. “But it was an immense effort every night for almost five months, and it was quite a bit of volunteer participation.” He added that the number of volunteers fluctuated.
At one public meeting with the Terre Haute Crow Committee, Bodwell informed people with basic information about the crows.
“Crows are awesome,” said the graduate student who is currently studying birds and their habitats in the Wabashiki Fish and Wildlife Area in Vigo County, “and they’re one of the smartest birds.”
During the crow count, Bodwell noticed their pattern. The crows gather in the trees on the outskirts of Terre Haute before waiting for dusk, Bodwell said. Once the sun set for the night, the birds would “stream in,” she added.
The effort to minimize the roost’s effects has evolved into a year-round endeavor. After the final crows left Terre Haute as the earth thawed in the early spring, the crow committee continued to hold meetings. During the group’s latest meeting in mid-August, members discussed potential grant funding, supplies and how to schedule volunteers for the coming year. Scott remains as an advisor to the group.
The committee hopes to get enough volunteers so that a schedule can be created in advance of the first birds’ late-autumn arrival. At times it can be discouraging, because they like the city and they’re not going to be driven away easily, though it’s also impressive, as the birds have flourished in an environment that humans have made, Scott said.
“The one thing you know for sure,” he said, “is they’re going to be back.”
Austin Arceo is ISU’s assistant director of media relations.