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. 

Playing the Healer of Nature

One of PrincetonNatureNotes' sister blogs is FOHWard.org, specific to our work and play at Herrontown Woods, the fabled preserve that our nonprofit Friends of Herrontown Woods takes care of. Posts range from the celebratory to the comic, as in when we intervened to scuttle an attempted "theft" of a portapotty. 

For those who imagine cutting invasive species to be dull work, a recent post on that blog, Stewardship and Discovery at Herrontown Woods, might be of particular interest. It captures how elements of beauty, effort, strategy,  serendipity, and discovery can come together to make a stewardship session a rich and satisfying experience. 

Cutting nonnative invasive shrubs, we are essentially deer with loppers. Deer move through the forest looking for something edible to browse. They generally leave the nonnative shrubs uneaten, and so to prevent those nonnative, inedible shrubs from taking over, we move through the forest with our loppers with an eye for "browsing" the nonnatives, to balance out the deer's persistently lopsided appetites. Unlike deer, we aren't in the woods 24/7, and so to have a lasting effect it's necessary to treat the cut stem so it won't grow back. By releasing native plants from competitive pressure, over time we make the forest more edible for deer and other wildlife, essentially expanding the acreage of functional habitat in Princeton. 

Some would say that humans are an invasive species, so who are we to presume we can make a positive difference. But if we can be considered invasive, we are also equipped to play the role of stewards, to see the consequences of our invasiveness and act to heal the altered earth. As we move deer-like through the forest, our appetite is not an extractive search for food but for restoring balance. To abdicate on that role would be to deny what it means to be human.

I don't know if deer can appreciate beauty or serendipity as they browse, but we can. In Herrontown Woods in autumn, each leaf reveals its inner color. Each boulder is a work of nature's art, mottled with varied shapes of lichen and moss, like the mottled skin of whales navigating the oceans. To steward a preserve is, of course, a considerable task and responsibility, but in another way, working with nature is a great privilege, allowing us to realize our highest role, as stewards, appreciators, and healers of nature's creations.

Still Here--A Late Fall Walk in a Desiccated Forest

On a Sunday morning in November, sipping coffee and socializing at May's Cafe in the Botanical Art Garden, 

a couple of us got to thinking: "Wouldn't it be a nice day for a nature walk in Herrontown Woods?" 

As we thought upon that thought, other thoughts sought to intrude. We are a merry crew--by habit, it would seem--finding some buoyancy even as beneath the usual merriment there has grown a deepening trepidation. The world is being rocked by disruption--politically, biologically, climatologically. These November days are discomfortingly comfortable, the woods are bone dry, the trees aching from drought. What will spring be like after a fall like this? In a world where disruption reaches into every nook and cranny, the very concept of refuge is under siege. We thought and thought, and thought some more until the answer finally came. Yes, we decided, a walk in the woods might be just what we need.

And so we set off, leaves crisp beneath our feet, down the red trail, then followed the silent cascade along the yellow. What to talk about? Beech leaf disease? Oh dear. I spoke of the color-coded forest--that special time in the fall when colors change and each species of tree and shrub announces itself with its distinctive color. Gaze around and grasp all at once from the reds and yellows, burgundies and browns, the species that inhabit that valley. Many of the colors were made pale by drought. Some trees and shrubs had simply dropped their shriveled leaves, short circuiting the color change, but still some colors showed. 

At the second stream crossing, it occurred to me: there might actually be flowers in this desiccated forest, in the middle of November. Native witch hazel blooms in late fall, unlike asian varieties that bloom in early spring. And yes, just off the trail, there it was, not just a sprig here and there, but a whole grove of witch hazel, massed larger than I'd ever seen or noticed, holding their countless flowers high.

One in our group, Jill Weiner, took this closeup of the curiously shaped and curiously timed blooms.

We hiked up to the cliff, to gaze out across the valley and scrutinize some interesting leaves. A white oak leaf had tiny holes--a sign of one of the hundreds of insect species that find sustenance in native oaks.

Looking out from the cliff, I saw a bright splotch of yellow, and headed down to have a look. It was a tree, though not much larger than a shrub. By the leaf shape and size, it appeared to be an American elm, a species whose grandeur I had witnessed in my youth, before it was laid low by an introduced disease. "Still here," it seemed to say. After all this, and all that, still here.

Cliff photo by Jill Weiner.

Native Fall Color and Berries in Herrontown Woods

One vision being gradually realized at Herrontown Woods through the power of incrementalism is the transformation of the long boardwalk into a native plant corridor that will be especially attractive in spring and fall. The boardwalk, given the V-ful nickname of Voulevarde because it was built by chainsaw virtuoso Victorino and leads from the main parking lot up to Veblen House, was intentionally routed past some mature examples of native shrubs.

Arrowwood Viburnum has toothed leaves (thus the latin name Viburnum dentatum) and can turn a brilliant reddish color in fall. 

We're managing the corridor for an open woodland, so that enough sunlight can reach the understory to power abundant berry making by the native shrubs. The many Blackhaw Viburnums, named after their black berries ("haw" means berry, as in hawthorn), are a dramatic example. 

The preserve's largest winterberry shrub--a holly called Ilex verticillata--greets you along a bend in the Voulevarde with abundant red berries this time of year.  

One of the preserve's large highbush blueberry bushes--they tend to be loners persisting here and there in the preserve--also grows along the route, with bright orange fall color.

The largest native swamp rose (Rosa palustris) in the preserve is also near the trail, its single pink flowers emanating a heavenly fragrance on hot summer days. Its rose hips are bigger than those of the nonnative multiflora rose. While the invasive multiflora rose is ubiquitous in the preserve, there are only two native swamp roses found thus far across 150 acres, mostly because the swamp rose needs more consistently wet conditions to compete. We've started planting more of them, in wet spots that get some sun, to see if we can increase their numbers over time. Again, the battle cry: "Incrementalism!"

Beyond the boardwalk, up towards Veblen House, is a good example of a rare native shrub, variously called Hearts a' Bustin' or strawberry bush. The deer love it so much that we needed to cage it until it was tall enough to escape their browsing. Located in a partial forest clearing, it receives enough sun to develop abundant berries.

In the fall, its leaves turn white. Hearts a' Bustin' is a native euonymus (Euonymus americanus), rarely seen due to deer browsing, while the nonnative euonymus, burning bush, is ubiquitous in the preserve and largely shunned by the deer. Notice a recurring story?

Up at the horserun near Veblen House, these look like shrubs or small trees, their fall color backlit by late afternoon sun. They are in fact trumpet vines growing on some sort of structure placed there decades ago. 

A different angle shows the trumpet vine with the bright red of Virginia creeper in the foreground. Both are native vines that can be a little aggressive, but sufficient shade deprives them of the energy to be obnoxious, allowing us to enjoy their best traits without any need to keep them in line.

Virginia creeper has five leaflets to poison ivy's three. These leaves look like they've donated some of themselves to the insect world. 

The boulders in Herrontown Woods, bedecked by mosses and lichens, are reminiscent of whales whose gray skin has collected barnacles. Sweetgum leaves are particularly creative and varied with their fall color.

Also generous with fall color is the native winged sumac, which has started to pop up in areas where we remove invasives. They seem to be part of the soil's memory of past eras when the forest was younger, before the canopy closed and shrouded the ground in deep shade. 

Another source of beauty, noticed while removing dead ash trees near the Veblen House driveway, is the combination of the old evergreen cedar trees with the deep burgundy of young white oaks rising to ultimately fill the space left by the ash.

The loss of ash trees to the emerald ash borer is a profound tragedy, but if we can take advantage of the new openings in the canopy to reawaken a diversity of native shrubs and trees, there is at least some recompense. 

New: Field Guide to Mushrooms in Herrontown Woods

Thanks to Peter Ihnat and his daughter Raisa for sharing their extensive knowledge of mushrooms in a Field Guide to the Wild Mushooms and Fungi of Herrontown Woods. 

Peter and Raisa return today, Sunday, August 4, to Herrontown Woods to lead a mushroom walk from 11am - 1pm. 

Raisa posts about the mushrooms she encounters on her instagram account, foragingwithraisa.

Helping Herrontown's Beauty Express Itself

There's a lot of built-in beauty at Herrontown Woods. Rocks, wood, and water serve as the basic infrastructure upon which other beauties are overlaid. 

This time of year, it's the understory that gets to shine, just before the tree canopy envelopes the woods in shade. Much of the habitat restoration work we do at Herrontown Woods involves bringing back the beauty and functionality of the native flora. By removing nonnative invasive shrubs that clog the understory, we open up vistas and release the existing native flora from stifling competition. In a sense, we are filling in for the deer, which chow down on native shrubs while leaving the nonnative shrubs uneaten.

Walk up the new boardwalk from the main parking lot to witness a corridor brightened by flowering dogwoods, 

and hundreds of blackhaw Viburnum shrubs adding clusters of white flowers extending deep into the forest.

Redbuds can't survive in the deep shade of the forest, but they proliferate on the more open Veblen House grounds.

This year, we spotted two wild azaleas blooming along Herrontown Road. Fifty years ago, it would have sounded strange to be excited about a couple wild azaleas in the preserve. They were numerous back then, but have been literally laid low by increasing deer numbers and deepening shade. 

It's taken more than a decade of ramblings in the preserve to realize that some kinds of native shrubs we thought long gone in fact remain numerous on the forest floor in miniaturized form, browsed before they can grow sufficiently to bloom. The town's deer culling program has helped native shrubs like spicebush to rebound, but for some species, additional effort is needed.

Protected by cages and given some sun, pinxter azaleas, serviceberries, and hearts-a-bustin' are making a comeback in the Botanical Art Garden (Barden) next to the main parking lot. New plantings of native buttonbush, silky dogwood, pussy willow and elderberry are also being protected until they can grow and flower beyond the deer's reach.

In these ways, we help another layer of beauty in Herrontown Woods to express itself.

Redbud Leaffolders and Orchids--Herrontown Woods in July

While the woods seems to slumber, July brings another wave of flowers at the Herrontown Woods botanical garden and the Veblen House grounds. Whether the number of flowers constitutes a wave or a ripple, the photography that is standing in lieu of an actual nature walk during COVID times captures something of the feel of walking the pathways.

I have seldom seen Culvers Root growing in the wild, but it is a native with a beautiful form to its flowers. You can see the flowers beginning to open at the bottom of a spike, commencing a slow progression upward that serves the pollinators well.

The mountain mint donated to us is thriving, its strong minty flavor protecting it from the deer.

Shrubby St. Johns Wort blooms for a long stretch in the summer, living up to its latin name, Hypericum prolificum. The deer leave it alone as well.

We human deer are letting a few pokeweeds grow to maturity. It has an annual stem growing from a perennial root, and can become too numerous if left unchecked. A previous post mentions the intentional or unintentional use of its berries as a dye, and an interesting tree-like relative it has down in Argentina, called the ombu.

Not sure what this soporific bumble bee was doing on a velvety leaf of wooly mullein, a dramatic nonnative weed I associate with rail lines in the midwest, but which shows up here and there in Princeton.

The drought prompted the installation of a gutter and cistern next to the roof of the kiosk at the Herrontown Woods parking lot. One rain keeps us in water for weeks, as we walk around the gardens, giving new plantings a much needed drink.

Insects have been taking advantage of the many kinds of native plants we're growing--more than 100 species thus far. Meadow rue, for instance, is a seldom encountered wildflower in Princeton, discouraged by shade and the appetites of deer. But in the botanical garden, we can grow it in a protected, sunny setting. On May 10th this year, one of the tall meadow rues was found "donating" its foliage to caterpillars of the Meadow Rue Owlet moth, Calyptra canadensis. Thus a protected setting for seldom seen plants provides habitat for specialized insect species that otherwise have slim pickings in Princeton.

Another giving was discovered a couple days ago, on a redbud tree, some of whose leaves were folded up and turning brown.

Strands of silk tether the leaves, making protective chambers within the wrappings.

Opening one up, like a clamshell, reveals some energetic caterpillars busy chowing down and leaving dark trails of frass in their wake.

The speedy caterpillars are larvae of the leaf folder moth, with the provocative latin name Fascista cercerisella. Readers will be relieved to know that the insect is not a fascist. Originally, the word meant "bundle", as in a bundle of sticks, which can be extended to bundles of people who are part of a political movement. A fascicle means a bundle of leaves or flowers, while the Fascista caterpillar bundles itself up in a folded over leaf. The "cerce" in cercerisella likely comes from the insect's preference for laying its eggs on redbud trees, Cercis canadensis.

Up the trail at Veblen House, a patch of wineberries is going uneaten. As we've been clearing the invasive growth on the Veblen House grounds, a neighbor lamented that we had removed her favorite patch of wineberries, whose fruit are one of the small rewards for those who persevere through the muggy heat of a Princeton summer. Responding to neighborhood input, we've kept a few patches of wineberries.

Few will notice that the green fringed orchids at Veblen House are in full bloom. We've caged some to protect them from the deer. Below is an enchanting closeup of the flowers, giving the impression of wood sprites.