The Dyson Tract area attracts a surprisingly wide variety of birds in a small sector along the Delaware and Raritan Canal State Park that can be traversed easily on foot. It’s a great “quick hit” stop on the Princeton/West Windsor border, just off Route 1 and close to a major shopping area on Nassau Park Boulevard.
The trick to the Dyson Tract is finding it. There’s a Dyson Tract along the Princeton Pike in nearby Lawrence Township, and that shows up prominently on Google and Apple map searches. That’s a fairly large park that I’ve visited a few times, but the concentration of birds is much lower.
The e-Bird Dyson Tract hotspot is just off a 90-degree curve on Quaker Road. Search for “Port Mercer Canal House” to find the hotspot. The town of Port Mercer flourished years ago, and the only remnant is the canal house, and the Dyson Tract parking lot is across the canal from it.
When you step out of your vehicle, you can start birding immediately. The red-tailed hawk topping this post was perched right next to the lot a few weeks ago. Barn and tree swallows swoop nearby in spring and summer.
From the lot, walk south through the D&R trail gate. You’ll likely see birds on the banks of the canal and, less often, the canal itself. As you walk south on the D&R towpath, to your right is a swamp that features ducks and geese of several varieties. I’ve seen great blue and green herons in there, and one of spring’s highlights in 2023 and 2024 was a prothonotary warbler that stuck around for a few weeks.
Walk a little farther south and you’ll see a wooden fence denoting a perpendicular trail. There’s a fairly large lake on the left of that trail while to the right the swamp extends back to the west. [October 2025 update: the swamp has been dry and covered with grass for the last few months. I don’t know why that’s happened.]
Belted kingfishers and herons are regular visitors, as are Eastern bluebirds, flickers, flycatchers, sparrows, woodpeckers and more. After a few hundred yards, the trail takes you through a fence gate, goes uphill briefly and then ends at an open area at the edge of a housing development. I’ve rarely seen anything worth spotting in that opening, so I turn around and retrace my steps to the parking lot.
The Jersey Birder 