Authorities at The Audubon Society of Portland have shared that they were getting reports of crows for the past decade. The earliest media reports about the roost were in January 2013. The reports noted “hundreds of crows have taken up residence” near SW 5th and Salmon and quoted observers saying that they had “never seen anything like it.” Since that time there have been local media reports documenting the winter roosting crows every year.
Our observations since winter 2017 have documented as many as 18,330 roosting crows at peak. Between October and February, typical counts documented well over 10,000, with roosting crows distributed on up to 70 blocks in an area encompassing over 400 square blocks of downtown Portland, Oregon.
The crows begin to arrive in the city before sunset and fly in from all directions in groups ranging from a handful to flights of many dozen birds. Pre-roosting is a raucous time when crows gather, vocalize, allopreen, and engage in impressive flight displays. However, by the time darkness overtakes the city, the crows have settled into hundreds of trees, become silent and sleep until just before dawn. Before sunrise, the roost wakes, crows call to one another across the city and then they depart for the day to forage. Crows may travel many miles daily to find food before returning to the roost for another night. This daily migration continues from October through March until the crows return to their breeding territories for the summer.
The Hazing of the Roost
Although the roost becomes silent and stationary after dark, some businesses, residents, and visitors to the city have been put off by the presence of the birds such that the Portland Clean & Safe organization has resorted to hazing the crows (which they call "abatement") in an attempt to disrupt and disperse the roost. The stated “problem” boils down to this: poop. Up until 2016, the city’s approach was to clean the sidewalks and other areas as needed to remove the droppings that were not naturally washed away by the Pacific Northwest’s persistent precipitation. However, in January 2017, Clean & Safe funded a month-long trial and hired falconers to haze the crows with hawks. Then, in the fall of 2017, Clean & Safe contracted with Integrated Avian Solutions (IAS) to harass, haze, and displace the roost using trained Harris’s Hawks three times per week for nearly six months. Hazing has continued each year from October-April. In the 2017-18 season Portland Clean & Safe paid $60,000 toward these efforts. Current expenditures are not published.
The Unproven "No Harm" Hypothesis
Although there has been much written about how to haze and displace roosting crows, and about the so-called effectiveness of a variety of hazing techniques, there has been no research designed to assess the potential harm to the crows individually, nor the roost --collectively-- that may be caused by hazing. We have reviewed dozens of scientific and ornithological documents, and directly queried researchers and other experts, but have (so far) found no evidence to support the assumption that intentionally frightening and displacing the crows causes no harm as they attempt to rest and conserve precious energy during frigid winter nights.
First Do No Harm
While it is common for people who support actions that intentionally disrupt natural animal behavior to use the “no-proof-of-harm” argument to defend their decisions and actions, we believe that the risks are too great. We support a philosophy that begins with not taking any actions that have the potential for harm unless and until there is clear evidence to support a “no-harm” hypothesis. Because of the lack of such research addressing the potential short- and longterm- negative effects on the roosting crows, we are seeking collaboration among all the interested parties: the City of Portland, Portland Clean & Safe, Integrative Avian Solutions (IAS) , The Audubon of Portland and concerned citizens.
As Cool As Swifts
For years the citizens of Portland have taken steps to protect and study what the Audubon calls “the largest known roost of migrating Vaux’s Swifts in the world!” Our vision is to foster an environment of co-existence and wonder in our city, to protect and treat the natural phenomenon of our urban crow roost with the same sense of respect, curiosity and awe as our swifts. Portland has become known around the world as the quirky place of microbrews, bicyclists and a place where people love their birds. We invite you to live the "Put A Bird On It" reputation and support your local corvids.
Portlandia’s invocation should apply to all creatures: “Follow that breath. Home is the journey we make.”
Please consider supporting us in our project by learning, watching, and advocating for the thousands of avian visitors to our city.
For more information on our Community Science Project, click here.
For more information on actions to Support Your Local Crow, click here.