Bird Photos
Species Accounts
Conservation Issues
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Modern Threats to
Bird Populations
General Information
Conservative estimates are that more than a BILLION birds are killed annually in the
USA as a result of human activities. Licensed hunting and pest control account for a small
portion of these deaths, but the vast majority of deaths result from a variety of other
human activities.
Let’s take a look at some of these activities to determine what we as responsible
citizens can do to curtail these needless losses to wild bird populations.
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Pet cats that are allowed to roam free
account for some 4 MILLION bird deaths EACH DAY in North America, or over 1 BILLION
songbirds each year. This figure does not include the losses resulting from feral or wild
populations of cats. Cats are efficient predators, and even capture some of the most
secretive birds, such as Yellow Rails.
SOLUTION: By simply controlling the activities of our favorite pet cats, we can make a
significant contribution toward conserving populations of songbirds.
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Figure 1 - The Domestic Cat
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Figure 2 - Windows
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As many as 80 million songbirds are killed
each year by collisions with plate glass windows. Most die of skull fractures and internal
injuries. Birds see reflections of trees, and fly directly into the window, often at high
speeds.
SOLUTION: This problem can be minimized by placing silhouettes of falcons on the outside
of the plate glass windows (See left side of this photo). Falcons are natural predators on
wild birds, and will usually cause a bird to veer away from the window, thus avoiding a
collision.
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More than 57 million birds are killed each
year from collisions with vehicles. This averages out to about 15 bird deaths per mile per
year.
SOLUTION: Most of these are probably not avoidable, but many can be prevented by careful
driving, especially in local areas where birds are known to cross roads frequently.
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Figure 3 - Road Kills
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Figure 4 - Communications Towers
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As many as 5,000 birds can be killed in one
night at a single tower site. Communication towers are particularly hazardous to birds
that migrate at night. Many species of birds migrate just above the treetops, and collide
with towers and guy wires. On misty overcast nights, the lights on the towers disorient
the birds, and as they fly around the towers, many are killed by collisions with the guy
wires.
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Nearly a million songbirds are killed each year by
collisions with lighted tall buildings. Once again, birds that migrate at night suffer the
most. Southern exposures present the greatest risk to birds coming north during the spring
migration. Northern faces of buildings are the greatest risk during fall migrations.
SOLUTION: Darken high rise buildings during the spring and fall migratory period.
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Figure 5 - Tall Buildings
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Figure 6 - Loss of Breeding Habitat
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The continued loss of critical breeding and
migratory stopover habitat to human development poses a devastating threat to wild bird
populations. The construction site pictured has been totally wiped clean of the mature
secondary forest that once existed here. Without suitable breeding habitat, birds cannot
maintain their populations. Without key migratory stopovers, birds cannot even reach their
breeding grounds. As human populations increase, this problem will likely worsen.
SOLUTION: Thoughtful land use planning can go a long way toward identifying and conserving
those habitats that are critical to birds and other forms of wildlife. Development that
does occur can be planned to preserve some habitat areas.
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Despite conservation efforts, millions of
songbirds are needlessly lost each year. The challenge is to educate people to those
things that can be done to minimize the threats to our native and migratory bird
populations.
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All images are courtesy of CWBO. All image copyrights are owned by CWBO.
Any use of these images must have permission of CWBO. |
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