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Fremont Bridge Nests

2001 Fledgling Peregrine

Fremont Bridge Peregrines in 2004: A Decade of Successful Nesting

In June of 1994, the Wildlife Care center received a call from a local veterinary clinic; a young Peregrine Falcon had just slammed into the window of a Rolls Royce dealership on Burnside and was lying on the sidewalk coughing up blood. The odds that it was really a peregrine seemed improbable. In 1994 there were only 26 known Peregrine Falcon nest sites in the entire State of Oregon and only one nest in the Portland Metropolitan area.

Earlier that spring a pair of unbanded peregrines had taken up residence on a pigeon dung-covered steel platform beneath the lower deck of the Fremont Bridge. Biologists, who had been tracking the slow recovery of the American Peregrine Falcon (Falco peregrinus anatum) since the listing of the peregrine under the Federal Endangered Species Act and the banning of the pesticide DDT in 1972, were elated when the pair produced a single female chick. Portland's Fremont Bridge was officially designated "Oregon Aerie (nest) 26" signifying that it was the 26th peregrine nest site to be established in Oregon since the recovery had begun. While still only a handful, it was a far sight better than in 1970 when nesting peregrines were nearly extirpated from the entire continental United States and eliminated from the Oregon landscape altogether.

Peregrine Falcons

Shortly after the first report, a second phone call came in. Rick Yazzalino, a keeper at the Oregon Zoo, was frantically calling to report the same injured peregrine. "Calm down Rick" I told him, "Odds are it isn't a peregrine." "Oh it's a Peregrine Falcon all right," he shrieked back at me, "I know because she is bleeding all over my back seat and she is about to die!" The falcon spent nearly a month at the Audubon Wildlife Care Center recovering from her injuries before she was well enough for us to take her back down to the bridge for release to complete her development under the tutelage of her natural parents.

Nestling Peregrines

Although peregrines typically nest on cliff ledges, there are records dating back to the Middle Ages of peregrines nesting on man-made structures. Although the urban landscape presents myriad hazards for wildlife, bridges tend to be particularly hazardous nest sites for peregrines. The dynamics of many bridges are such that peregrines tend to fledge prematurely and plummet to the water or roadways below. Those that survive the initial fall must often spend several days hopping about on the ground before they attain the ability to fly.

fremont release

After the travails of 1994, serious consideration was given to removing future eggs or chicks from the Fremont Bridge nest site and fostering them into wild land cliff nest sites where they would likely face fewer hazards. The opportunity to allow urbanites to experience firsthand the presence of these magnificent birds flying overhead and our ability to provide for them on the urban landscape was pitted against the importance of doing everything possible to maximize their likelihood of success. In the end, it was a pragmatic recognition that peregrines would inevitably continue to attempt to nest upon our urban landscape that won the day. The recovery would best be aided by developing strategies to allow them to successfully nest upon the urban landscape rather than transporting them elsewhere.

Peregrine Female

In 1995, the Oregon Department of Fish and Wildlife and Audubon Portland collaborated to develop the "Peregrine Watch Program," an intensive effort to raise Portlanders' awareness and appreciation of the fierce predator slicing though the clouds overhead. Jeep Pagel, Peregrine Specialist for the US Forest Service, worked with us to establish the monitoring protocols. The Oregon Department of Transportation adopted innovative management strategies and funded research into the nesting behavior of bridge dwelling falcons. A huge cadre of volunteers donated their time to help educate visitors, monitor the falcons and provide dawn to dark protection for young falcons during the hazardous fledging process.

The effort has more than paid off. During the past decade the Fremont Bridge peregrines have fledged thirty-three youngsters. Of those, all but three have fledged prematurely and benefited from the mobile Peregrine Falcon restriction zones quickly established by vigilant volunteers. Fifteen youngsters have required some form of major intervention including being pulled from in front of oncoming cars and trains and being hauled from the river by kayak.

Restricted Peregrine AreaOne youngster was rescued from the bottom of a six foot deep hole used by the homeless community as a latrine and another was recovered after being harassed by an intoxicated person. Juvenile falcons have been struck by cars, run into windows and even been hit by a bicycle requiring rehabilitation ranging from one day to more than a year. The awareness and concern of the local human community has been instrumental in the success of this site as they have alerted us to potential problems, often been the first to sight ground-bound falcons and tolerated periodic area restrictions while nearby falcons learned to fly. More than once, Ross Island Sand and Gravel on the east side of the bridge has turned off a gravel loader as a young peregrine plummeted into harms way. Despite our best efforts, there have also been eleven fledgling mortalities during the past decade.

Peregrine Watch

Today Fremont Bridge is recognized as the second most productive peregrine nest site in the State of Oregon. At least four of the young who fledged off the Fremont are known to have established nest sites of their own, and those nest sites have produced at least an additional 20 youngsters. Our prediction back in 1995 that peregrines would continue to attempt to occupy other bridges in the Portland area was accurate and today five of the 111 known nest sites (greater than 4%) in the State of Oregon occur in the Portland Metro Area.

Challenges still remain. Peregrines were delisted Federally in 1999, but remain listed as endangered in the State of Oregon. Despite a lack of quality data regarding current peregrine population trends, the US Fish and Wildlife Service decided in 2004 to allow falconers to remove up to five percent of the annual western Peregrine Falcon nesting productivity from the wild for the purpose of being held in captivity for falconry. Oregon's State Endangered Species Act will protect them in this state but we could soon be seeing falcons being removed from the wild just across our borders. This decision is currently being opposed in court by Audubon Society of Portland and other conservation groups. Additional causes for concern include the potential population impacts of West Nile virus, the recent discovery that widely used flame retardant chemicals are showing up in high quantities in Peregrine Falcons, and the as of yet unexplained peregrine population declines in Northern Scotland. We must remain vigilant.

A decade after they fledged their first youngster, the same pair of falcons still nests high above the Willamette River on the Fremont Bridge. In late June of this year they successfully fledged another three youngsters. In 1995, Jeep Pagel climbed into the nest and replaced the layers of pigeon poop with a more typical peregrine nesting substrate of gravel, but otherwise little has changed, other than perhaps our perception of the viability of bridge nesting peregrines and the role that our urban ecosystem can play in the recovery of a species.

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