Birds disappearing – 06/16/2007

  • November 30, 2013 at 11:43 pm #1564

    from mirakulu:

    The Sparrows that normally land in my huge Hawthorn tree did not come
    this year.

    That silence you hear is birds . . . disappearing
    Nature – Many have declined by at least 50% since the 1960s, due to
    development, pesticides, cats

    • For a full accounting of the decline of birds, by species and
    locale, go to:
    Saturday, June 16, 2007

    Spotted owls might get the attention, but many of Portland’s most
    common backyard birds — including the Western meadowlark, Oregon’s
    state bird; and the Swainson’s thrush, known for its melodic morning
    call — are disappearing, too.

    The rufous hummingbird that winters in Mexico but returns to the
    wooded Northwest to breed — and delight many while hovering at
    backyard feeders — has declined 79 percent in Oregon over the past 40

    Even those familiar signs of spring — red-breasted robins — declined
    nearly 3 percent per year in the Portland metro area over the same period.

    “There are a lot of species that we take for granted around here that
    are having real trouble,” said Bob Sallinger of the Audubon Society of

    While these birds are not fading so fast they are near extinction, the
    declines mean hundreds of millions fewer filling the skies and
    chirping from tree branches nationwide. It’s happening even as
    bird-watching is one of the fastest-growing pastimes, pursued by about
    one in four of all Oregonians.

    In Oregon, the state bird has nearly vanished from the Portland metro
    area as its grassland habitat gives way to housing and parking lots.

    Nationwide populations of 20 common birds fell at least by half during
    the past four decades, according to National Audubon Society figures
    released Thursday. Audubon scientists gauged the trends both
    nationally and in Oregon from two annual bird surveys: Audubon’s
    Christmas Bird Count and the U.S. Geological Survey’s summer breeding
    bird survey.

    “You don’t necessarily see their declines, because they’re still so
    common, but just because they’re around doesn’t mean they’re doing
    well,” said Lori Hennings, a natural resources scientist with Metro
    who has long studied Portland birds and tracks their numbers in the
    Portland area using some of the same survey results.

    The likely culprits include development that slices and dices bird
    habitat, urban predators such as house cats raiding nests and wide use
    of pesticides that kills the insects birds eat, biologists said. Cats
    are the top cause of injuries to birds brought to Portland Audubon’s
    care center, Sallinger said.

    Those problems may be increasingly compounded by global warming and
    tropical deforestation, especially for birds that migrate between the
    Northwest and the tropics.

    Hennings found many bird species are declining faster within the
    Portland area than in the rest of the state, probably because of more
    rapid conversion of habitat to human uses. The Portland trends are
    based on a bird survey route from Tualatin to Milwaukie.

    But Portlanders can take some solace, because the region is far ahead
    of other metropolitan areas in protecting habitat for birds, Hennings
    and Sallinger said. The trouble is, so far, that hasn’t been enough to
    reverse the declines.

    “We’re far ahead of most American cities, but a lot of what we’re
    doing today is still fixing the problems of the past,” Sallinger said.
    “We put our cities typically in the same kinds of places that
    historically are good places for wildlife” — such as along the
    confluence of rivers.

    Urban dwellers can do plenty to help birds find a home: plant native
    landscaping and trees and create refuges for birds. Hennings found
    that the more native plants along streams, the more native birds that
    are likely to hover there.

    Portland lies in a critical spot along the Pacific Flyway, a major
    north-south migration corridor for millions of birds — large and small.

    “We have a chance to slow down this decline,” Hennings said. “Just
    planting one tree makes a huge difference,” since a single tree may
    hold 10 bird nests and thousands of insects.

    “One person doing something alone may only help a little, but 10,000
    people doing something together makes a huge difference,” she said.

    Portland is one of seven cities nationwide to sign an Urban
    Conservation Treaty for Migratory Birds with the U.S. Fish and
    Wildlife Service, committing to protecting habitat and promoting
    bird-friendly measures.

    Sallinger is working to create a wildlife corridor linking Johnson
    Creek with the Columbia Slough on the east side of Portland. The goal
    is to help neighborhoods along the way provide useful habitat in areas
    as small as backyards so birds and other wildlife can flit and flutter
    between the two waterways.

    “It’s very easy as an urbanite to point your finger and say, ‘People
    out there — ranchers, farmers, loggers — need to do their share,’ ”
    Sallinger said. “They do, but we also have to play our part.”

    Not all birds are suffering; some actually benefit from urbanization.
    The Vaux’s swift, once known for roosting in the hollows of big
    old-growth trees, took quickly to using chimneys instead. The birds
    draw crowds each September to Chapman School in Northwest Portland,
    where they swirl into its chimney in the evening.

    Vaux’s swift numbers climbed about 6 percent a year in the Portland
    area during the past four decades, according to Hennings’ studies. The
    metro population of black-throated gray warblers rose more than 23
    percent a year, probably because they like leafy trees that
    proliferate in urban areas and grow back quickly after logging.

    Unfortunately, they’re the exception to the larger rule of declines.

    “The spotted owls and the marbled murrelets of tomorrow are going to
    be birds like the yellow warbler and the willow flycatcher,” Sallinger
    said. “These species aren’t endangered today, but if we don’t act,
    they may be tomorrow.”

    Michael Milstein: 503-294-7689; michaelmilstein@…

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