By Max MatzaBBC News, Washington
Bird attacks on humans are growing more common as people continue to encroach on bird nesting territory, wildlife experts warn.
Mary Heiman was walking her dog around a lake in downtown Denver, Colorado, in late July when a bird started flying uncomfortably close to her head.
Before she knew what was happening, the bird "body slams you in the back of the head, flies around frantically and then goes back in the bush", she told the Denver Post.
"It's funny," she said. "It's just startling when it happens."
Andrea Jones, the director of bird conservation for the California chapter of environmental organisation National Audubon Society, says attacks are definitely rising.
"The increase we're seeing is because we're encroaching on bird habitats. So there are more bird-human interactions," she says.
Most of the incidents arise when birds are trying to raise their young. Nesting birds are very defensive of their chicks - "like a mama bear", she says - and will even attack animals much larger than themselves.