Interstate Bridge Peregrines and Osprey
Bob Sallinger, Portland Audubon conservation director | April 2012
Portland is full of amazing birds of prey. Yesterday I spent the morning perched atop the Interstate Bridge. Peregrines have nested on this bridge since 2001 and last year osprey also began nesting on the bridge. Peregrines, like osprey, have adapted to substitute man-made structures for their natural nesting habitat.
Once endangered, peregrine falcons thrive in Portland's urban landscape, Audubon finds
Katy Muldoon, The Oregonian | April 2011
Portland's peregrine falcons have survived plunges into rivers and onto freeways, oncoming locomotives, explosions, bongo-playing hippies, a petulant Hollywood director and a motorcade carrying former President Bill Clinton.
The birds, formerly on federal and state endangered-species lists, routinely defy the myth that urban areas are lousy places to raise young, says Bob Sallinger, Audubon Society of Portland's conservation director. Seventeen years ago, he started the city's annual Peregrine Watch, a nest survey and educational effort, which gets under way again this month.
Last spring, after the 50th chick fledged from the Fremont Bridge since nesting began there in 1994, Sallinger decided to take stock of the species' success in and around Portland, and to celebrate its vigorous rebound from near extinction 40 years ago. Conservationists nationwide consider the falcons' return one of the Endangered Species Act's great success stories.
Oregon Field Guide: Falcon Comeback
OPB | First broadcast 2010
In 1970 experts couldn’t find a single peregrine falcon in Oregon. 40 years later they are off the endangered species list thanks partly to a large number of nests right in the city of Portland, many on the largest, noisiest bridges. The falcons still face threats from intentional illegal hunting. The Audubon Society of Portland tracks and bands chicks born each year.
Portland Peregine Nest Site Sets Record for Number of Fledglings
By Bob Sallinger, Portland Audubon conservation director | 2009
Peregrine Falcons typically lay 1–4 eggs, with the average number of fledglings per nest being just over one per nest site. A peregrine nest with 5 young has only been documented once in the western United States, at Beacon Rock in Washington in the 1990s.
This season a Portland-area nest site located on one of our local bridges matched that record. We were excited to learn that the nest had 5 eggs, but even more thrilled when we went in to band and discovered that all 5 eggs had successfully hatched!
This past spring Audubon has been participating in nationwide peregrine monitoring efforts to access nationwide population trends. Portland Audubon and a team of nearly 30 volunteers were responsible for monitoring all of the Metro-area nest sites. Over the years our local bridges have played a significant role in statewide Peregrine Falcon recovery, and our own Fremont Bridge is ranked as the single most productive nest site in Oregon over the past 15 years. Now our urban nest sites have another claim to fame — the most young produced at an Oregon nest site in a single season!
Five Peregrine Falcons Successfully Released to the Wild at Ridgefield National Wildlife Refuge
Visitors to Ridgefield National Wildlife Refuge this summer may look up to see the spectacular sight of five juvenile Peregrine Falcons dog-fighting with one another as they practice improving their flying and hunting skills! The falcons' presence at Ridgefield is the result of an effort to protect the productivity of Oregon's bridge-nesting peregrines, led by the Audubon Society of Portland in cooperation with the US Fish and Wildlife Service-Ridgefield National Wildlife Refuge, Oregon Department of Transportation, Oregon Zoo, Oregon Department of Fish and Wildlife and Clark Public Utilities.
The five falcons released at Ridgefield all came from nests located on Oregon bridges. Although Peregrine Falcons typically nest on cliffs, they also substitute bridges and skyscrapers. Unfortunately, bridges present serious management challenges. Many of Oregon and Washington's bridges are in need of repair and are scheduled for construction during the next few years. While the goal is always to allow nesting peregrines to complete their nesting cycle without disturbance, Audubon Portland, Oregon Department of Fish and Wildlife and Oregon Department of Transportation recognized that there would be some construction projects where disturbance would be inevitable In 2001, a plan was developed to protect these peregrines and their offspring. Where nest failure appeared likely, eggs or nestlings would be removed from the bridge and raised in captivity. When they developed to the point of being able to fly, they would be released to the wild using a technique known as "hacking."
Three of the five birds released at Ridgefield were taken as eggs from the St. Johns Bridge on April 12th, 2003. just in advance of the major construction project that would have completely enveloped the nest location. The eggs were immediately transported to an incubator at the Oregon Zoo's Center for Species Survival. The eggs hatched on May 6th and 7th. At 10 days of age, the nestlings were transported to the Audubon Society of Portland where they continued to be cared for until June 14th, when they were placed in the hack box at Ridgefield. During their time in captivity, the young were fed either with a peregrine puppet or through a feeding chute to avoid imprinting them on humans.
Two additional birds, one from Portland's Fremont Bridge that was run over by a bicycle immediately after taking its first flight, and a second that fledged prematurely off the Astoria-Megler Bridge and could not be reunited with its parents, were later added to the group, bringing the total to five.
Hacking: At the age of 35 days, the peregrines were placed in a box atop a 30-foot tall tower that Ridgefield National Wildlife Refuge allowed us to construct on Bachelor Island.
Clark Public Utilities generously donated materials, time, personnel and equipment to build the tower. Audubon Portland volunteer Ken Barron constructed the hack box. Ken also donated more than a month of time to live out on the refuge and serve as hack site attendant (see related article next page). The objective was to have the falcons associate the tower with food so once released, they would continue to feed on food placed on the tower daily. Falcons instinctively begin to hunt, typically within a week of beginning to fly, but will not become proficient for several weeks. Providing food at the tower replicated the support that they would have received from their parents.
As of late July all five peregrines continued to be observed flying and hunting at Ridgefield. By early August the peregrines should be proficient hunters and feeding at the hack tower will be discontinued. Sometime during the winter the youngsters will likely disperse off the refuge for good. The hacking tower will be utilized when necessary in future years. While Bachelor Island - where the hack tower is located - is not open to the public, the young falcons have been frequently observed throughout open areas of the refuge.
Thanks to all of our partners in this project!
Oregon Zoo, Oregon Department of Fish and Wildlife, Oregon Department of Transportation, Ridgefield National Wildlife Refuge, Clark Public Utilities, PGE, and Mason, Bruce and Gerard. Thanks in particular go to Ken Barron, Kelli Walker, Shawn St. Michael, Kelli Hoffman, Brook Beeler, Melinda Trask, Kendel Emerson, Holly Michael, Jennifer Brown, Eric Anderson, Joe Engler, Tom Murtaugh, Jim Wilmarth, Carole Hallet, Tracy Flemming, Cindy Humphreys, Marli Lintner, Jeff Wittler and the crew at Clark Public Utilities, Steve Hagen and the crew from PGE.