It seems as though every year, the congregating crows catch people off guard.

Thousands of crows flock to Portland's park blocks each winter, darkening the sky at dusk and roosting overnight in the city's trees. Much about the crows' habits is unknown.

From Granger and Provorse’s perspective, the hazing is unwarranted: The crows’ droppings, they say, are barely noticeable, usually gone within a few days due to rain, and that hazing only shifts the location of the droppings to another part of the city. They also feel that the crows deserve to use the city to their advantage and that preventing them from roosting at their chosen sites may be detrimental to the health and survival of the crow population at large. But overall, they object to the hazing not “because we claim to have solid evidence that hazing the crows harms them,” Granger says, but “rather because there is no evidence at all in either direction.”