Another interesting articles about birds, migration and urban environments.

Valerie Shahan
Lummi Bay
Valerie.Shahan at wwu.edu

http://news.excite.com:80/news/r/010531/10/science-environment-birds-dc


News Article: Skyscrapers Turn Out Lights to Save Migrating Birds



CHICAGO (Reuters) - The man-made mountain range that looms
over Lake Michigan is noticeably dimmer on spring nights, not
because of an energy shortage but to keep migratory birds from
slamming into Chicago's clusters of glassy towers.

Each year about 100 million birds across the United States
are killed in crashes into windows or die from exhaustion after
becoming mesmerized by lighted buildings, scientists say.

"Any one building might be killing 2,000 birds a year,"
said Doug Stotz, an ornithologist at Chicago's Field Museum.

Now more than a dozen Chicago skyscrapers and lakefront
buildings have turned off outdoor lights or closed window
shades and drapes to reduce the toll on migratory birds. Their
actions cut bird deaths by 75 percent or more, scientists say.

"Whether birds are striking buildings, communication
towers, power lines, or hitting airplanes or getting whacked by
cars, they are all mortality factors," said Al Manville, a
wildlife biologist with the U.S. Fish and Wildlife Service.

"The most vulnerable are the 350 migratory species such as
vireos, warblers, and thrushes," many already endangered, he
said. "Pesticides, herbicides, even house cats kill many
birds," he said, adding that thousands of songbirds would be
spared if pet cats were kept indoors during migration season.

Some 5 billion migratory birds travel across the eastern
half of the United States during spring and autumn migrations.
They fly at night, avoiding airborne predators, and navigate by
starlight, moonlight and geographical clues such as rivers and
lake and ocean shorelines, scientists say.

BIRDS ARE CONFUSED

In a phenomenon that is not fully understood, the birds
become confused by building lights, particularly on cloudy or
misty nights. They circle like moths around a flame until they
are exhausted, or crash into windows that either appear
transparent or reflect the surrounding terrain or sky.

Some birds are fooled by mirror-glass skyscrapers along
East Coast and Great Lakes flyways, both densely traveled
routes between their winter havens in the tropics of Central
and South America and their North American nesting grounds.

In Chicago, City Hall took up the crusade to darken the
city's impressive skyline during bird migration season.

"Some buildings shine colored lights for the holidays, so
we said, 'What about celebrating or recognizing migratory birds
by dimming your lights?"' said Jessica Rio of Chicago's
Department of the Environment.

"Before the program began there were a lot of dead birds on
the roof during migration season -- it was a decent cleanup
job," said Roy Endsley, manager of the 65-storey Three-Eleven
South Wacker tower.

He said few bird deaths occur now that the downtown tower's
signature lighted crown has been doused for several weeks twice
a year. And bird watchers have spotted 80 different species
lingering in the small patch of greenery astride the building.

Birds not diverted to the city's concrete jungle find an
oasis in its lakefront parks, though some fall prey to an
increasing number of urbanized raptors including peregrine
falcons and kestrels.

To provide the migrating birds a hiding place and food, the
parks department adopted environmentalists' suggestions to
plant more native trees and shrubs and delay grass mowing.

DRAWN INTO DEATH TRAPS

Sadly, migratory birds often fly thousands of miles, some
using every ounce of energy to traverse natural barriers such
as the Gulf of Mexico, only to be drawn into death traps by the
lights and glass windows of urban sprawl, scientists say.

"If this were a well-recognized problem -- if people saw
dead birds lying at the entrance -- I think that many
architects would be persuaded to not use reflectorized glass,"
said Shankar Nair, chairman of the Council on Tall Buildings
and Urban Habitat, a group of engineers and architects.

Windows are indispensable tools for architects, "bringing
the outside in and the inside out" in daylight, and lighting
illuminates the impressive skyline at night, Nair said.

"I don't think any architect wants to see his building
blacked out when others are not," he said. But more Chicago
building owners are seeing the light by shutting off theirs, a
group representing the owners said.

"We're not enduring the same energy crisis that's going on
in California, but building owners might be able to save a few
pennies" while performing a good deed, said John Colgan of
Chicago's Building Owners and Managers Association.

Meanwhile, volunteers in Chicago, New York and Toronto --
where the "lights out" program first began in the mid-1990s --
continue to scoop up dead or stunned birds beneath the towers.

"I'm trying to constantly impress upon people that these
are not the pigeons, gulls, or geese that are dying, these are
birds with endangered populations," said Michael Mesure, who
runs Toronto's Fatal Light Awareness Program (FLAP).

The U.S. Fish and Wildlife Service's Manville said more
than 200 birds species are "in trouble," with nearly half of
those heading toward extinction.

TRAMPOLINE FOR BIRDS

In New York City, a stopover for birds migrating along its
coastline or the Hudson River, few buildings have taken
precautions. The landmark twin World Trade Center towers did
stretch thin netting across the facades on lower floors that
safely bounces wayward birds off like a trampoline.

But most skyscrapers crowding lower Manhattan take a toll
on a variety of songbirds and shore birds, according to
volunteers seeking to publicize the lights-out effort. Birds
are found dead or stunned beside glassed-in garden atriums or
vainly seeking shelter in tiny planters following collisions.

"Habitat that can make cities livable for humans can become
deadly for birds," said Rebekah Creshkoff, a volunteer tracking
bird deaths in the city.

She said she has sought to educate building owners about
saving birds by turning out lights, replacing transparent or
reflective windows with solid-looking glass, planting trees
flush against buildings and installing netting.

"It is slow going," she added.

Scientists say the fragmentation of forest habitat caused
by development may be too big a hurdle for some songbird
varieties, regardless of efforts to smooth their migration.

Some species that require a buffer of forested land to nest
successfully are losing ground, providing an opening to natural
enemies such as the increasingly populous cowbird, which
prefers the forest edge.

A cowbird noses an egg out of a songbird's nest and lays
one of its own to be raised by the surrogate parents, often
spelling doom for the songbird's own slower-developing chicks.