When humans and ospreys collide | Kitsap Week

Man-made structures become irresistible to ospreys as nesting sites. But this can have dangerous consequences.

By GENE BULLOCK

Kitsap Audubon Society

Poulsbo’s two osprey chicks are flapping their wings like athletes warming up for the big game. But for them the “big game” will be surviving on their own.

In the meantime, dad dives for fish in a nearby pond behind the North Kitsap School District’s horticulture building, while mom guards the nest and chirps instructions to her busy mate. The pond provides a dependable source of fish, which make up 99 percent of the osprey diet.

The pond’s proximity explains why this pair thinks it has found such a perfect spot for a nest. For several years they’ve nested on top of a light tower in Strawberry Field, a soccer field next to Poulsbo Middle School on Hostmark Street and Noll Road.

We’ve watched the graceful bird as he perches in the branches above the pond and scans for movements below the water’s surface. Uniquely adapted for the job, he fixes on the slowly swimming fish, briefly hovers, and then plunges into the water, emerging with a squirming meal in his talons. He eats the head so the chicks won’t choke on the sharp-edged bones, and then delivers the rest to the hungry chicks, while mom comments. It’s a family scene repeated several times each day as the chicks grow nearly as big as their parents.

Ospreys are found nearly everywhere in the world where they can fish. During the 19th and 20th centuries the main threats to osprey populations were egg collectors and hunters. But populations declined drastically in 1950s and 1960s because of pesticides, such as DDT. The toxic effect caused the eggs to be thin-shelled, easily broken or infertile. But ospreys, eagles and peregrine falcons have all made significant recoveries since DDT was banned in the early 1970s.

Today their main threats come from eagles and man-made structures. Ospreys like to build their nests on the highest point they can find near a ready source of fish. This gives them a commanding view so they won’t be ambushed by eagles. Although they are smaller than eagles, their agility gives them a tactical advantage in the air.

This predilection makes cell towers irresistible. It has become a growing problem as cell towers multiply to meet the rising demand. But the nesting materials are flammable, and contact with electrical equipment is a hazard for both the birds and the cell tower owners. Prohibited by law to tamper with nests while they are in use; owners now wait until the birds have left for the winter and replace the nests with excluder devices to prevent the birds from rebuilding them. When the birds return in April, they’re forced to find new homes. Many are now nesting on light towers — such as the one at Strawberry Field — creating another fire hazard, and safety and health problems such as falling debris and excrement.

Public utilities have a long history of providing alternative platforms and other devices to keep raptors from electrocuting themselves and causing power disruptions. But it’s a new problem for cell tower owners and contractors, and they are struggling to find solutions. Evicting the birds solves one problem, but often creates another. Many communities are rallying support for these very popular birds and erecting nesting platforms to accommodate them. The charismatic osprey is an icon and mascot for many athletic teams, including our own Seahawks football team.

The Kitsap Audubon Society is exploring a relocation of the Poulsbo ospreys. Osprey expert Jim Kaiser has identified two suitable locations close to the Poulsbo pair for a new nesting platform. Kaiser is a retired wildlife biologist with the U.S. Fish and Wildlife Service. He has assisted in more than 300 nest platform installations on the West Coast and offers a consulting service for those dealing with the problem.

The Kitsap Audubon Society’s mission is to preserve the natural world through education, environmental study, and habitat protection; and to promote awareness and enjoyment of local and regional natural areas. Find them online at www.kitsapaudubon.org.

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