"FREMONT -- For nearly two years, BART has been involved in an exhaustive effort to shoo away hundreds of pesky birds laying eggs along the rail extension under construction toward Silicon Valley -- even installing those inflatable dancers popular outside used-car lots. 

Our DNA says rest here  (sparrows)
The cost to taxpayers: $5 million -- or more than $17,000 per nest. But BART says it's money well spent. Agency officials say the bird-related problems would have delayed BART's extensions to Warm Springs and San Jose, costing much more public money in the long run if its contractors hadn't spent millions of dollars in overtime to stay on schedule.

....  With the project site sitting along the route birds fly to migrate south, mallards, sparrows, doves and several other species flock to the lush, wooded area to lay eggs, which is a problem since most species of migratory birds legally can't be disturbed once settled in the nest. They kept coming back, no matter what the workers did -- and they tried just about everything, from installing sprinklers and nets to physically destroying the nests and separating bird couples before they could mate and lay eggs."

Yes, all of you out!  (mallards)
....  The construction contract, awarded to builders Shimmick Construction and Skanksa for $137 million in 2009, has since increased $11 million because of the extra bird costs and other changes. The subway, which is virtually done now, is part of an $890 million, 5.4-mile extension into the Warm Springs district of south Fremont, which is expected to open in 2015. It's the first leg of a rail line slated to reach Milpitas and San Jose's Berryessa neighborhood by 2018.
We were here last year  (doves)

Wildlife problems have plagued BART before when building rail line extensions. When constructing the Peninsula line toward San Francisco International Airport early last decade, crews discovered a dead San Francisco garter snake -- an endangered species -- which briefly delayed work and cost BART more than $1 million. Medved said while a few eggs did crack during the Fremont project, this time the agency avoided any work stoppages and was not fined by state regulators."  Read more.

Related BART Warm Springs project.  And  San Francisco Chronicle/CBS, 3/13/12, "San Jose BART extension starts work in April."  The Cornell Lab of Ornithology,  "All about Birds/Migration."  "The origins of long-distant migration patterns are more complex and include the development of the genetic make-up of the bird."

Posted by Kathy Meeh