The Herrontown Amphibian Report: 2026

The eggs are laid in the vernal pools. The frogs and salamanders have scattered into the nearby woods. They migrated later than usual this year, delayed first by snow drifts that lined the road where they normally cross to reach their vernal pools. But the snow melted and along came a few relatively warm, rainy nights to lubricate their movement across the road and through the forest.

Long before the annual spring migration of woodfrogs, spring peepers, and spotted salamanders began, the weather was being closely watched by the Princeton Salamander Crossing Brigade, a group founded by Inge Regan, a board member with the Friends of Herrontown Woods. Volunteers attend late-winter training sessions at the Sourlands and elsewhere, then benefit from the expertise of Brigade members Mark Manning, Fairfax Hutter, Lisa Boulanger, and Mark Eastburn.

The work of the Salamander Brigade, now in its fourth year of helping amphibians safely cross the road, was greatly helped by a collaboration this year with the Princeton Police Department, which has placed blockades across the road during rainy nights. The blockades reduced car traffic almost to zero, allowing the vast majority of amphibians to safely cross the road. 

As described in some excellent CBS News coverage earlier this week, traffic in previous years led to the loss of up to 40% of the amphibians, despite the valiant efforts of the Brigade to help them across.

This year, Brigade members met at dusk on four different nights, in raincoats and reflective vests, with powerful flashlights to monitor and document the migration. 

Those who had never held a salamander got the joy of doing so.

It's not always easy to take notes on weather and amphibian numbers out on a roadside in the rain. It helps that Dr. Regan has long experience writing up charts for patients. The data gets sent to the Sourlands Conservancy, then on to the state wildlife agency. 

Over four evenings, volunteers counted 40 spotted salamanders, 7 woodfrogs, and 52 spring peepers. 

Those raucous spring peepers you hear in spring are incredibly tiny.

The spring peepers seem to be doing okay, but the low number of woodfrogs is concerning. Last year there were dramatically fewer woodfrog egg masses in the main vernal pool in Herrontown Woods, and this year again they are greatly reduced. In June last year, there was a mass dieoff of tadpoles in another pool. A Rutgers professor studying wildlife diseases said ranavirus has been hitting some populations in NJ. 

That pool, not far from the main parking lot of Herrontown Woods, fortunately has lots of eggs again this year, both woodfrog and the whitish clusters of salamander eggs. 

One of the more comic moments was the spotting of a male woodfrog trying to mate with a salamander. The salamander wanted nothing to do with it. In fact, the salamanders don't directly mate. Rather, the males show up at a vernal pool ahead of time, deposit spermatophores, then wait for the females to come along to pick them up. The system seems farfetched, but the proof is in the eggs that will soon hatch. Hopefully, the vernal pools will keep enough water to sustain the tadpoles and salamander larvae as they grow to adulthood in these little oases in Herrontown Woods. 

Volunteer Cozy Sierra caught the spirit of the Princeton Salamander Crossing Brigade in a t-shirt she had made. 

Why Would CBS News Come to Herrontown Woods? Salamanders!

Word is out about the Princeton Salamander Crossing Brigade, founded by Friends of Herrontown Woods board member Inge Regan in 2023. On Monday, March 23, CBS News New York came a'knockin' and ended up interviewing Inge and Herrontown neighbor Lisa Boulanger about the work volunteers are doing to help salamanders and frogs safely cross the road during their spring migration to nearby vernal pools. The Princeton Police Department is also featured, having played a critical role this year by closing the road during the warm, rainy early spring nights when amphibians are on the move. Amazing how quickly the news team can generate a fine portrait of our activities.

How to Protect Lingering Ash Trees in Princeton?

Last June, I was driving down Herrontown Road when I noticed something very unusual. Scientist Louis Pasteur once said that "Opportunity favors the prepared mind," and that's certainly true in this case. My mind was very well prepared to notice that one of the trees growing in front of a house was healthy while those on either side of it were not.

Just six months prior, I had researched and written a post entitled Seeking "Lingering Trees"--Some Hope for Ash and Beech Trees. The post encouraged readers to keep an eye out for lingering trees, i.e. ash or beech that were still looking healthy while those around them were dying. And here, along Herrontown Road, I witnessed the very phenomenon I had read and written about. 

That line of tall trees is all ash trees. All but one have succumbed to the depredations of the introduced insect called Emerald Ash Borer (EAB) that has been devastating millions, more likely billions, of ash throughout the eastern U.S.. Not having co-evolved, our native ash tree species lack resistance to this nonnative insect. Hitchhiking into Michigan in wooden packing crates from China in the 1990s, EAB spread eastward arriving in Princeton in 2015. What ten years ago was Princeton's most common native tree is quickly becoming its most rare, impacting all the fauna dependent upon it for food. 

But here, in this area of northeastern Princeton, there's some conspicuous survival going on. These two healthy-looking ash were growing near the first one I saw.

Though it's hard to say at this point whether these are true survivors, this would not be the first time Princeton played host to native trees unusually resistant to introduced insects and disease. There's the "Princeton" variety of American elm that has shown resistance to Dutch Elm Disease. And we're having some luck thus far with bringing back the native butternut from nuts gathered from two lingering trees then growing on the Textile Research Institute property overlooking Carnegie Lake. Butternuts have been laid low by an introduced canker disease.

Unfortunately, we'll never find out if two of those lingering ash along Herrontown Road might have survived. They were cut down by a tree company yesterday. Last fall, I had knocked on the door to alert the owner to the remarkable surviving qualities of their ash trees. No one was home, and I forgot to follow up. Sometimes, I get the feeling like there are holes in the universe where I was supposed to be.

I've reached out to the town arborist and open space manager, to see if there's any way "lingering" trees could be inventoried, and homeowners encouraged to protect them, so that any local resistance can be given a chance. 

Update: Princeton's arborist emailed me the following: 

"At this time, the ordinance permits the removal of all ash trees with no questions asked regardless of condition or history of injection."

Update, 3/26: Rachel Kappler, whose Ohio-based research into resistant strains of native beech and ash I have written about, sent the following advice for people encountering "lingering" ash and beech:

I am one of the collaborators assisting with lingering ash reports but in NJ I would focus on reporting them to the Forest Health department of the NJ state forest. You could also use the free phone app Treesnap, which allows scientists to see you entered trees. They end up prioritizing them and contacting owners when samples are needed. Find out more at Treesnap.org

Native Plant Workshops at Herrontown Woods

This spring, I'm offering some informal, hands-on native plant workshops at the Princeton Botanical Art Garden ("Barden") in Herrontown Woods. The next one is from 10am to noon this Saturday, March 14, at 600 Snowden Lane. 

The first one was last Saturday, and it was such a pleasure to play the role of mentor. New volunteers Angela and Sabrina came, and each took on various projects to cut last year's flower stems and set the stage for a new season. Angela gained introduction to rose mallow hibiscus, the still fragrant stems of wild bergamot, and various others as she went around the "Veblen Circle" of wildflowers, cleaning out the cages. She was thrilled by the site of buds at the base of a cupplant, which led to a conversation about the role imagination plays in gardening. Sabrina cleaned out dead stems from around one of our sculptures, and helped me prep a raingarden where cutleaf coneflower and buttonbush will soon sprout.

The Barden, a forest clearing where sun-loving wildflowers and shrubs can prosper, is a perfect setting for learning about nature and our positive place within it. If you're interested in plants, and want to help out, come by. There's a lot of learning that grows out of doing. It's very informal at this point. Check the HerrontownWoods.org website and Herrontown social media for upcoming sessions. Thus far, they are happening on Saturday mornings starting at 10.

Kari Lloyd--Bringing People and Nature Together in Princeton

Nature has a new ally in Princeton, a new source of organizational energy that in its initial stages feels transformative. Long active as the organizer of the Hopewell-based NJ Native Plant Swap and other ventures, Kari Lloyd has now come to Princeton as the K-5 STEAM teacher at Littlebrook Elementary, and has brought her organizational energy with her. 

Her first event was the Native Seed Sowing Extravaganza, which brought 100+ parents and kids together in the Littlebrook cafeteria to put some seeds in the ground.

It being Feb. 5, the ground came in the form of pre-moistened potting soil. 

  

Kari had lots of well-trained helpers, as families chose from an impressive selection of seeds, 

then planted them in plastic gallon milk jugs. Some helpers had gotten jugs by the hundreds from coffee shops, others cut them in half (leaving one corner as a hinge), then partially filled them with potting soil. Others instructed participants in how to scatter their seeds on the soil and tape the jugs back together with packing tape. And don't forget to scribble the name of the plant on the jug. Cost per jug was $5, making the event something of a fundraiser for the school. 

There to witness the event were members of a number of longtime Princeton environmental organizations that themselves have been gaining momentum over time--Friends of Princeton Open Space, Sustainable Princeton, and the group I lead, Friends of Herrontown Woods. 

Princeton can feel like a cocoon at times, wrapped up in itself.  In addition to longtime regional institutions like the Watershed Institute and DR Greenway, a lot of energy and expertise has been gathering in the small towns and countrysides beyond Princeton's borders. While Princeton has its Friends groups--FOPOS and FOHW, and the lesser known FoRR--Hopewell has its FOHVOS, short for Friends of Hopewell Valley Open Space. We've benefitted in the past from periodic visits from the FOHVOS NJ Invasive Species Strike Team, but Kari is the first to my knowledge to plant herself firmly in Princeton, and bring all that wonderful nearby environmental energy to town. 

She arrives at a time when Princeton has made great strides in preserving the last tracts of open space, and has begun to undo decades of neglect as we chip away at the massive invasions of nonnative species on preserved land. But at the same time, there remains a widespread disconnection from nature, where the tending to one's yard is outsourced to crews whose mission is to purge and simplify. There can seem little time or inclination to surround one's home with anything more than grass. Still, there's a sense of momentum in the air. The seeds are in the soil; the milkjugs have been carried home. Hopefully the sprouts will stir curiosity about the plant world, and inspire people to take on the challenge of deciding where to plant them, and remembering to tend to them.

Next on Kari's docket is organizing a series of monthly family hikes in Princeton and Hopewell, beginning with a hike in Herrontown Woods, to be led by myself and Hopewell Valley-based Nicole Langdo, founder of Painted Oak Nature School.