YORKTOWN, VA., NOV. 6 -- The domestic harmony of a peregrine falcon may upset the harmony of commuters should the falcon's presence on the George P. Coleman Bridge halt or delay the bridge's widening.

The female falcon has called the York River bridge home since 1988. The falcon is protected under the federal Endangered Species Act of 1973. Should the bird return next summer with its mate, plans to widen the only link between Virginia's Middle Peninsula and Hampton Roads might be threatened.

As an endangered species, the falcon and its nesting areas are protected from the harassment or harm of man.

"I would say 'harass and harm' could fit, considering what they plan to do with the bridge," said Daniel H. Hurt of the U.S. Fish and Wildlife Service. However, Hurt said it is too early to tell whether the construction project would violate the law.

The state Department of Transportation wants to spend $94 million to widen the bridge from two lanes to four, said Jim Cleveland, construction engineer in the department's Suffolk office. The bridge is a major bottleneck for commuters to and from the Hampton Roads area.

"The worst-case scenario as we see it would be a delay in construction," if construction is halted from March to July when the birds mate and nest, said John J. McCambridge Jr., the department's environmental manager. That would push the project's completion from the summer of 1996 to late autumn of 1997.

"No one's sure whether the birds will ever be back to the Coleman. One thing's for sure, the bridge will be built," he said.

There's no evidence that the falcons produced offspring last spring or used a nesting tray that was hung underneath the bridge in the spring of 1989, officials said.