WASHINGTON — The Secret Service will widen the security perimeter around a duck nesting outside the U.S. Treasury building ahead of protests expected during weekend meetings of the International Monetary Fund and World Bank.

Earlier this month, the brown mallard laid nine eggs in mulch around a recently planted tree outside the Treasury. The Secret Service, which protects the White House and the Treasury, placed gates around the duck to protect it as well.

"We have been informed of protests scheduled outside Treasury in concert with the IMF-World Bank-G7 spring meetings," Rob Nichols, assistant Treasury secretary for public affairs, said in an e-mail to reporters. "We are widening the perimeter around the duck as a precautionary measure."

Some demonstrations at economic summits in recent years have turned into violent confrontations between police and protesters. Tens of thousands of anti-globalization demonstrators shut down a 1999 international-trade ministers meeting in Seattle, and protests disrupted World Bank-IMF meetings in Washington in 2000.

Workers yesterday erected a second line of metal crowd-control barriers about 10 feet outside stanchions already in place to keep gawkers at arm's length from the duck.

Nichols declined to say if Treasury Secretary John Snow, who visited the bird last week, had ordered the increased protection. "We don't comment on security matters," he said.

The duck — dubbed "T-Bill" and "Duck Cheney" by Treasury employees — spends her days nibbling mulch around her, dozing in the spring sunshine and feathering her nest. Every evening at dusk, she covers her eggs and leaves for about 15 minutes to feed, a Treasury official said.

The eggs are expected to hatch this month.