This is a load of crap

Beware the pigeon terrorists! They will destroy our society as we know it!

Actually pigeon droppings are able to corrode bridge steel beams faster:

Pigeon droppings contain ammonia and acids, said chemist Neal Langerman, an officer with the health and safety division of the American Chemical Society. If the dung isn't washed away, it dries out and turns into a concentrated salt. When water gets in and combines with the salt and ammonia, it creates small electrochemical reactions that rust the steel underneath.

"Every time you get a little bit of moisture there, you wind up having a little bit of electrochemistry occurring and you wind up with corrosion," said Langerman. "Over a long term, it might in fact cause structural weaknesses."
Langerman emphasized that he wasn't saying pigeon dung factored into the collapse of the 40-year-old bridge. "Let's let the highway transportation and safety people do their job," he said.

The problem is familiar to bridge inspectors everywhere.

The Colorado Department of Transportation spent so much time cleaning pigeon manure off bridges that it is embarking on a two-year research project looking for ways to keep pigeons away from its spans.
"It can be damaging to our structures because it's slightly acidic and it has other compounds in it that can dissolve especially things like concrete," said Patricia Martinek, the agency's environmental research manager.

Pigeon guano isn't just a danger to the bridges.

In the Denver area, the Colorado DOT pays outside environmental specialists to clean bridges wearing full biohazard suits with respirators because of heightened fears about bird flu and other diseases, said Rob Haines, who supervises maintenance there.

Keeping pigeons off bridges usually requires a multi-pronged strategy that can include netting to block holes and surfaces, spikes to keep them from landing, and sometimes poisoning, shooting or trapping the birds, said John Hart, a Grand Rapids, Minn.-based wildlife biologist with the U.S. Department of Agriculture.

So, will it soon be lawful to poison the pigeons in the park?



Or maybe to take them home to cook them?

Update 8/26: Even postal workers have a hard time with bird poop:

WASHINGTON, Aug. 26 The all-natural refuse left by a persistent flock of starlings in one Washington neighborhood has even driven off postal workers.

Postal Service spokesman Deborah Yackley said while the government organization lives under a credo of overcoming nature's obstacles, the constant barrage of fecal matter from the birds is simply too much to ignore, The Washington Post reported Sunday.

"Our carriers do have the right to determine that a location is unsafe or hazardous for them to deliver," Yackley said. "The mess extends all the way across the sidewalk and into the street, so it's impossible for them to get to the mailbox without going through it."