Looking for Frogs in All the Wrong Places with Paul Lewis, Clarkson '58

NY State Rt. 121 winds past expansive estates, horse farms, verdant fields and abundant woodlands. With Paul Lewis as a guide, however, student researchers learned that this idyllic Westchester County landscape belies an ecological tragedy.

Paul Lewis, Corey Ng, Haylei Peart, Leah Deegidio.

Paul Lewis, Corey Ng, Haylei Peart, Leah Deegidio.

At one stop in the Town of North Salem, he explains, the highway floods in spring and passing cars crush frogs moving from the vernal pool on one side of the road to the upland on the other. The students — Corey Ng, Cornell ’17, Haylei Peart, Pace ’17, and Leah Deegidio, Pace ’15 — are investigating wildlife mortality hotspots on Westchester’s state highways.

Lewis, a mechanical engineer, amateur naturalist, and resident of nearby Lewisboro, is a keen observer of the local environment who reports problem spots like Rt. 121 to the NYS Department of Environmental Conservation. After graduating from Clarkson in 1958, he spent most of his career with the DuPont Company.

I worked on everything from textile fibers, to explosives and ammunition manufacturing machinery, and finally on centrifuge design for use in blood processing and research. My main hobby now that I have retired is birding, but one of the things I love to do is lead Vernal Pool walks in the spring. They are fascinating places and most people don’t know anything about them. They are amazed once they learn.

Wood frog, Lithobates sylvaticus.

Wood frog, Lithobates sylvaticus.

Vernal pools are temporary pools of water that fill and drain according to season. Largely unknown ecosystems, they are part-time home to species such as frogs, fairy shrimp and salamander. It is not unusual to find them alongside highways that have bisected wet areas and altered the local hydrology. Frogs lay their eggs in vernal pools and migrate back upland, sometimes across the highways that interrupt their natural habitat.

According to Tom Langen, Clarkson chair of biology:

It is becoming apparent to conservation professionals that road mortality and disruption of habitat connectivity is causing declines and local extinctions of sensitive species whose populations are divided by roads.

[…] Segments of roads that are crossing points . . . can be the site of mass deaths that result in rapid population declines, since all mature animals in a local population are likely to attempt to cross the road going to or returning from breeding.

Lewis brought the students to three more locations, each with similar characteristics, each a busy local thoroughfare that cut through the wet, wooded environment favored by turtles, salamanders and frogs.

“I have been interested in frogs since I was a little kid,“ he told his young charges. They smiled and understood.