On her daily walks along Sheridan Road in Winnetka, Teri Weber often enjoys the views of Lake Michigan. However, during a stroll on the 400 block of Sheridan, she suddenly faced an unusual experience. Red-winged blackbirds began dive-bombing her without warning. “The first one came from behind, and then the second one came toward my face,” Weber recalled. She quickly reacted by ducking, waving her hat, and shouting.

Her encounter is not unique. After she shared her experience on social media, 50 people responded. At least six other locals reported similar experiences with aggressive birds.

Nancy Davidson, another resident from Wilmette, described a similar incident. Just last month, while following her usual fitness routine along Sheridan Road, she too encountered the dive-bombing birds. “I was completely surprised, as the bird came out of nowhere,” Davidson shared. It struck her head, urging her to immediately leave the area. She was unaware of this bird species before this occurrence.

According to Wilmette Park District’s JP McNamara, these birds are common in Illinois during the early nesting season. Male red-winged blackbirds become particularly territorial and aggressive. This behavior has been noted in areas like Sheridan Road and Gillson Park, where birds protect their nests from perceived threats. “While the behavior can be startling, it is generally intended to deter potential predators rather than cause injury,” McNamara explained.

Experts assert that these actions are normal. Bridget Kiernan from the Chicago Botanic Garden observes increased aggression in male red-winged blackbirds during this time. “The behavioral trait of male red-winged blackbirds to defend their territory and protect their offspring, at times aggressively, has allowed the species to become so successful,” Kiernan stated. These birds often establish nests near water and in wetlands, with June being the peak time for dive-bombing as the chicks hatch.

Chicago resident Leah Pietrusiak also had a dive-bombing encounter near the Humboldt Park Boat House. After sharing her experience online, others recounted similar events. Pietrusiak recalled an earlier incident two decades ago while biking on Grand Avenue when birds attacked. Recently, during an early morning walk, a bird hit her head once, which she saw as a warning.

Weber suggests that local officials might take measures to deter birds from nesting in public places before they lay eggs. The Migratory Bird Treaty Act of 1918 and the Illinois Wildlife Code protect these nests once eggs are laid. Until then, residents can take precautions, like wearing wide-brimmed hats during nesting season. Kiernan recommends being attentive to the birds’ high-pitched warning calls. “Red-winged blackbirds are very vocal and give off warning calls when they sense there is any danger,” she said. Knowing these sounds allows people to avoid the birds’ territory.

For anyone interested, the National Park Service offers audio files of the birds’ sounds for reference.