Birds & Tower Kills 3

July 22, 2011

Okay, here’s some “overkill” on the Birds & Cell Phone Tower Threat–see the previous two posts if you want the summarized version, but if you’re REALLY interested in this topic, try these websites:

Sibley Guides:  Causes of Bird Mortality

Towerkill.com

 

 

 

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Birds & Tower Kills 2

July 22, 2011

From TOWERING TROUBLES:

“…Our TV and cell phone habits are contributing to the deaths of millions of migratory birds a year. The birds collide with the communications towers …and with the cables that anchor the towers. Those towers become sky-high death traps for birds, who then drop in grass, streets, parks, and fields, and on rooftops….conservation groups and government biologists estimate that communications towers kill from 4 to 50 million birds a year. They endanger or threaten at least 50 species….

The construction of new towers is deadly news for migratory birds. The tower-bird collisions occur (1) during spring and fall migrations, and (2) at night, when songbirds travel to avoid the heat and daytime predators. For birds, such as whooping cranes, that fly during the day but cannot see the power lines, the towers and lines are the Number One migration danger.

…Many of these nighttime travelers can cross oceans and navigate mountain ranges. What makes them crash into the blinking, lighted towers? Scientists aren’t certain. The worst kills happen when a flock, which might number half a million, flaps toward a lighted tower. Something about the lights attracts the birds. Red beacons seem to draw birds more than other lights do, although studies suggest that red wavelengths may disrupt the birds’ ability to navigate using the stars or the earth’s magnetic fields. The weather may play a role, since large kills almost always occur on cloudy or foggy nights. Fog, mist, or storms increase the odds of trouble. Unlike larger birds, which can climb above the clouds, smaller migrants sometimes try swooping underneath, right into the path of towers. “


Birds & Tower Kills 1

July 22, 2011

From the NJ Audubon Society:

“‘An estimated 5,000 to 10,000 birds, mostly Lapland Longspurs, were killed on the night of January 22, 1998, at a 420 foot tall communications tower in western Kansas. Apparently a heavy snowstorm sent the birds up looking for bare ground. Dense fog caused the tower’s aviation-safety lights (required on structures over 200′) to reflect off water in the air and form an illuminated space, causing the birds to switch to their diurnal (visual) mode of navigation. The flock circled the lighted tower and collided with its guy wires. Some birds were impaled by wheat stubble, suggesting they were so disoriented that they couldn’t tell which way was up and flew into the ground at full force. The tower had three white strobes. This is interesting because it has been suggested that flashing lights cause less mortality than steadily illuminated lights. Evidence suggests that continent-wide, communications towers kill 2 to 4 million songbirds each year.’ (American Bird Conservancy, Bird Calls, March 1998).

…five tower kill studies done in the eastern US in recent decades all showed kills of roughly 1,000-3,000 kills per year….

The problem is caused by the lights on the towers for aviation warning. On nights with a low ceiling, birds lose their cues for stellar and geomagnetic navigation. The light reflecting off water molecules in the air causes an illumined area, creating a whirlpool of birds circling the tower in the light space…

Some of these documented cases of tower kills are very revealing. Many of them indicate a very high percent of forest Neotropical long-distance migrants, especially warblers.”

The full, longer article on this, is at the link above.


Walking Bird

July 11, 2011

Very clear video of a bird walking around:


Running Birds

July 11, 2011

This has comic potential:


Flock Formation

July 10, 2011

Ever wonder why birds tend to migrate in a V-formation?  It turns out that there are many evolutionary and ecological factors that have influenced this customary pattern.  Check out this interesting article from Life’s Little Mysteries for more information:

Life’s Little Mysteries: Why Do Bird Flocks Move in Unison?

For a visual glimpse of birds assembling and flying in V-formation, please watch these informative videos:

National Geographic: Masters of Migration

Birds in Flight: Up Close and Personal


Winged Migration

July 10, 2011

 

Each year, birds from around the world take flight on an incredible migratory journey.  This feature film, Winged Migration, reveals an in depth look into this natural phenomenon.

Here are the links to all YouTube videos for this film:

Winged Migration: Part 1

Winged Migration: Part 2

Winged Migration: Part 3

Winged Migration: Part 4

Winged Migration: Part 5

Winged Migration: Part 6

Winged Migration: Part 7

Winged Migration: Part 8