Farbotnik, an environmentalist, quickly realized that he had chanced upon - luckily, without also flattening - a surge of salamanders in the heat of their annual breeding rite. Jumping out of his truck, he kept oncoming traffic at bay as he shepherded the slithery paramours from one swampy side to the vernal pool on the other, there to hook up.

A half-dozen mating seasons have passed since then in upper Bucks County, and Farbotnik, now 31, has presided as crossing guard at each. On the first mild, rainy evening of late winter or early spring, he heads for the 518-acre Quakertown Swamp, a favored haunt of not only salamanders but also frogs, toads, birds, and muskrats.