Construction hits snags — weather delays, equipment trouble, cost overruns.

Sometimes even talons.

And no, that pair of red-tailed hawks perched on either arm of the gold cross atop the steeple of Grace Episcopal Church aren't going to budge, not even for the scaffolding of a $12 million renovation project. Not when there's a pair of chicks nestled in the crook of a pinnacle below.

The mockingbird harassing them can't drive them off. The house sparrows nested nearby just leave them alone. And if a construction crew member ventures to the top of the highest scaffolding level just below the nest, one of the hawks spreads its 4-foot wingspan and drops to circle the steeple menacingly.

"They're fine. They appear to be acclimated," said Rebecca Elliott, U.S. Fish and Wildlife special agent. They ought to be; the law is on their side. The federal Migratory Bird Treaty Act prohibits the taking of the birds, their eggs or their chicks. And besides, this is the raptor whose shrill shriek has been used in movies for years to send that eerie chill up your spine.

So the Wentworth Street church has to wait seven or eight weeks to reinforce the steeple of the 160-year-old sanctuary — and pay a pretty penny while doing so.

Elliott climbed the scaffolding this week to determine whether there were chicks in the nest, and she spotted at least two. There might be a third in the nest, she said, but she didn't stick her head in there.

The aerie has been there all along, but no one realized it was occupied until the uppermost tiers of scaffolding were erected last week, about the time the eggs hatched.

As snags go, it's a big one, said Bovis Lend Lease project manager Seth Armstrong. But it's "just something you've got to work around." The crew will keep working as high as three scaffolding levels below.

The cost of the delay, so far, will be a minimum of $60,000, the price of renting the scaffolding. It's one of those things nobody wants to see happen, said Holly Behre, church communications director. But what's a welcoming congregation to do?

"It's a great example lofting above our church spire," said the Rev. Canon Michael Wright, the church rector, as he shielded his eyes with his hand to watch the brooding hawks. "We need to be reminded occasionally the world is bigger than our struggles."

Church members, for their part, are taking the long view. Rebecca Martin, director of the Little School at Grace Church preschool, watches them daily.

"I think it's just beautiful," she said, "the birds perched on the cross."