Leading a Frog and Flower Walk this Sunday, 11am-noon

Herrontown Woods is packed with life this time of year. Frogs are hoppin' and native flowers are poppin'.  

With the chance of rain diminishing to 10%, I'm going ahead with a frog and flower walk this Sunday at 11am. All are welcome. Looks like May's Cafe will add even more life to the Barden, from 9-11, with coffee and baked treats. 

There's so much to see. Tadpoles are growing in the vernal pools. 

Hundreds of native pinxter azalea flowers are just starting to open.

And as the flowering dogwoods begin to fade, the clustered blooms of blackhaw viburnums polka dot the understory with white.

Address is 600 Snowden Lane in Princeton

A Big Fish Story in Herrontown Woods

Herrontown Woods seems an unlikely source of a big fish story. 

Its multiple streams take but a few steps to cross. A sustained drought slows them to a trickle and dries some up altogether. It can feel like an event to spot a minnow while crossing the main channel on the yellow trail. How did it reach that far up, given the challenge posed by the cascades some distance downstream? When a boy named Felix found a crayfish in a stream next to the parking lot some years ago, it was a revelation. 

The only big fish story told until this spring was the tall tale popularized in an article in the October, 1981 Princeton Recollector, entitled Farming Small in "Herringtown". Written by Jac Weller, who owned a farm where Smoyer Park now stands, the article states that Herrontown Road was originally called Herringtown Road, named after the herring that farmers would haul back from the shore in wagons to fertilize their crops. The soil, the story goes, was so poor up along the Princeton ridge that the laborious trip was worth the trouble.

Like many a good fish story, this one's hard to confirm. That fabulous historical research tool, the Papers of Princeton, compiling digitized newspapers dating back to the early 1800s, offers no evidence that there ever was a Herringtown or Herringtown Road. The Herringtowns that pop up in word searches prove only to be someone's misspelling of Herrontown. Still, I found appealing an explanation told to me by John Powell, longtime farm manager for Jac Weller. Long after Weller departed from this world, John lived in a house at Herrontown Road and Snowden Lane, raising two head of cattle each year on his six acres. In an email to me, John told the story this way:

"The story I have on Herrontown Road is that it was where fish wholesalers lived, on small farms on land owned originally by the Gulick farm, a very large farm. When the road became part of Princeton, its name was dressed up so as to suggest the bird."

In other words, or in the case of this particular word, Herrontown is a hybrid, part fish, part fowl. The idea that fish wholesalers would congregate along the eastern ridge makes at least a little sense, it being downwind of the town and of little value for agriculture. And might there have been a time long ago when the herring migrated upstream to Princeton each spring, saving the farmers a trip to the shore? 

It was with these thoughts in mind that I arrived in Herrontown Woods to lead an ecology walk for the Princeton Adult School on April 4. I was waiting in the parking lot for the participants to arrive when I saw out of the corner of my eye a great blue heron flying up through the trees, heading away from where the red trail crosses the preserve's main stream. I had never before seen a great blue heron in Herrontown Woods, and in that brief instant thought I saw something large hanging from its beak. As it flew away, I strained for another view to confirm, but the dense canopy got in the way. 

Our walk followed an arc along the red and yellow trails, with talk of Herrontown ecology soon eclipsing any thought of that curious heron seen earlier. Then, crossing the main stream on the red trail to return to the parking lot, we heard a splash and saw something incongruously large slicing the surface of the water. There, visible beneath the reflections on the water's surface, were two large fish, about a foot long. Clearly, we weren't in minnowland anymore.

We oohed and ahhed, wondering what sort of fish they might be. I wanted them to be trout, or even better, herring, to make more conceivable the story that the word Herrontown had grown out of Herringtown, just as a real life heron would grow from eating herring. A new logo for Herrontown Woods rose to mind: a heron flying with a herring sticking out of its mouth, or perhaps a chimera--a mermaid with a fish's body and a heron's head. 

After finishing the walk, I headed back to explore further. That's when I took this video:

 

The two fish, alas, proved not to be trout, nor herring, but instead bore the far less appealing name of white sucker, named after their white belly and mouth angled down to eat from the stream bottom. Also called brook suckers, they are native to the eastern U.S. and midwest, living in lakes or streams, then swimming upstream to spawn in the spring. When they spawn, a female is often bounded on both sides by males whose semen mingles with the thousands of eggs released into the stream by the female. There's no nest, nor any followup care. The math of two males to one female would work in this case, if the great blue heron actually did carry off the other male, leaving just two fish. Herons have a remarkable ability to spot dinner in small bodies of water around Princeton. We twice lost our goldfish when a heron came to visit our backyard minipond. 

A friend, Fairfax Hutter, who grew up just a quarter mile downstream of Herrontown Woods, remembers the annual migration of foot-long fish upstream to spawn. Most memorable was when a boy in the neighborhood caught a pair of fish and tried to get them to spawn in a bathtub.

Despite the lowly name, the white sucker is native, and a powerful swimmer that has a salmon-like ability to overcome myriad physical obstructions to reach its spawning grounds. Its annual journey to Herrontown Woods connects us to the romance and ecological power of the great spring migrations of the past, when shad, menhaden, and river herring swam up the Millstone River to spawn. Did these other species reach up into small streams like Harry's Brook as well? 

Though the Carnegie Lake dam prevents any return of shad and other anadromous fish species to Princeton, there have been efforts to remove two smaller dams downstream on the Millstone to bring spring migrations further up the Millstone.  

Shadbush is a native shrub so named because it blooms early in spring when the shad are making their journey up our eastern rivers to spawn. It grows wild in Herrontown Woods, but for decades was kept from blooming by deep shade and hungry deer. Some years back, we transplanted a few of them to the Barden, where sunlight and protection has allowed them to bloom once again. 

Through land protection that began with the Veblens and Herrontown Woods, some stewardship, and the serendipity of a well-timed stream crossing on April 4, we now know that when the shadbush bloom, big fish will come a' courtin', and a great blue heron will come a' huntin', as they have for thousands of years.

Who Put the Harry in Harry's Brook?

Since google's AI could not answer the question this morning, it seems time to get the word out as to how Harry's Brook got its name. Harry's Brook, for those unfamiliar, drains the eastern half of Princeton, emptying into the Millstone River portion of Carnegie Lake not far from Kingston. Even a relatively small brook has many origins. The main branch originates in Palmer Square, flowing in a concrete culvert under downtown Princeton until it daylights at Harrison Street. Another branch flows east from Princeton High School and the Princeton Shopping Center. 

The cleanest tributary originates high on the boulder-strewn ridge in Herrontown Woods.  

It was Maine-based mapmaker and internet sleuth extraordinaire Alison Carver who figured out how Harry's Brook got its name, in a free-ranging correspondence with me back in the Covid days of 2021. My original question to her had been "who put the Herring in Herrontown"--a related question whose answer remains elusive.

Harry, it turns out, was really a Henry, as in Henry Greenland. I first learned that Harry was a nickname for Henry while researching Henry Fine, the man who did so much to build Princeton's math and science departments in the early 20th century, including bringing Oswald Veblen to Princeton in 1905. Old Fine Hall, and the newer math building as well, were named in his honor. 

Alison sent me a series of maps that showed the evolution of the brook's name, 

from Greenland's Brook

to a combination, in which the outlet was called Greenland's Brook with one of the branches being called Harry's Brook,

to a map that shows the whole thing getting called Harry's Brook.

How far back does the name go? The first mention of Harry's Brook in newspapers dates back to 1878, but Harry goes back much farther than that. The Municipality of Princeton has a webpage entitled Historic Princeton that states:

"In 1683 a New Englander named Henry Greenland built a house on the highway which is believed to be the first by a European within the present municipal boundaries. He opened it as a "house of accommodation" or tavern. Portions of this house survive within the Gulick House at 1082 Princeton-Kingston Road."

The tavern was strategically located halfway between New York and Philadelphia, a day's horse ride from each. Is there something of Harry in the name of the road that bordered his land, Herrontown Road? 

An email from Alison shows the spirit of inquiry:

"I did a little research … Harry was the first landowner in the area. He had about 400 acres, (about 2/3 of a square mile) part of which is now the Gulick Preserve … but the cool thing is that Herrontown Road runs along the north edge of it. So, I wonder if Herrontown Woods was named after the road? And how old that road is? If it’s really old, then maybe the road was Henrytown or Harrytown, something like that, and it got changed over the years … it has a gap in the middle of it which makes me think it must have been an old road, since maybe that part was a footpath or was let to grow over …

questions questions …"

Salamanders and Frogs in Herrontown Woods--Spring Goings On

This is the third spring that the Friends of Herrontown Woods (FOHW) has helped frogs and salamanders safely cross Herrontown Road on their way to their breeding grounds in vernal pools. The work of the Princeton Salamander Crossing Brigade is documented in a blogpost on this site from last year, and in an article this week in the Town Topics. This year the Brigade was able to collaborate with Princeton's police department, which closed the road on one of the nights when the amphibians were on the move, dramatically reducing the customary carnage from road traffic down to zero. FOHW is hoping to collaborate similarly with the police department in the future.

Along with upcoming nature walks about amphibians during FOHW's Earthday celebration on April 13, I co-led an amphibian walk this past weekend, described below. Another walk I'm leading on April 5, through the Princeton Adult School, about plant life and forest ecology at Herrontown Woods will also touch on spring amphibian behavior and still has a few spots open. 

The walk at Herrontown Woods this past Saturday delved into the lives of frogs and salamanders along the ridge. We were fortunate to have two members of the Princeton Salamander Crossing Brigade with us. Inge Regan (second from left), who started the Brigade two years ago, is passionate about helping the frogs and salamanders safely migrate to their breeding grounds. This involves helping them avoid getting squashed by traffic when they cross the road on rainy nights in early spring. 

Neuroscientist and Crossing Brigade member Lisa Boulanger is very knowledgeable about amphibians, and brought along a couple red-backed salamanders she had found under a log that morning. These small but numerous salamanders don't need a vernal pool to lay their eggs. Lisa brought along the two color phases: red-backed and lead-backed.

Our first stop was a small pond we had dug in the Barden a couple years ago as part of a Zen Garden. I had placed a "refugia" in the bottom of the pond. An earthen pond in our piedmont clay will hold rainwater for days or even weeks, but ultimately the water seeps into the ground. Sinking a black plastic tub into the bottom of the minipond creates a refugia to sustain frogs and other water-loving creatures through droughts. This pond hosted adult green frogs and their young through last summer, and this spring during the walk, Lisa found a white glob of salamander eggs in the pond. Very flattering that the salamander community has found our little pond to be egg-worthy. (Info on mosquitoes and miniponds in this post.)

Nearby, not far from the parking lot, we stopped by a small but mighty vernal pool that holds water longer than others in the woods. This little pond was created naturally. Years ago, a tree blew over, and where its rootball had been, the depression for a vernal pool was created. The clay under this pool is so dense that the water doesn't seep in, but instead remains to sustain hundreds of frog and salamander larvae until they can grow to maturity. 

One curious observation we've made this year is that wood frog eggs, usually dominant in the vernal pools, are this year very few. No explanation for this scarcity as yet.

During the walk, Lisa was busily turning over logs in search of the most charismatic salamander in the woods, the spotted salamander. Finally, near a vernal pool deeper in the woods, she found one and showed it to all the participants. 

Lisa has taken many photos of the salamanders crossing the road on rainy nights, including the one below. You can see why these wild creatures are much loved.

A Special Bluff With Special Flora

There are places in nature that feel special in some way, places we find ourselves returning to. One special place for me is a bluff in the lower valley of Ellerbe Creek--a stream in Durham, NC for which I founded a watershed association a quarter century ago. 

During a recent visit, I took a walk with naturalist Cynthie Kulstad in one of the preserves we created back then, 80 acres called Glennstone Preserve. Cynthie is the botanist/horticulturist who helped sustain many of the plantings I had nurtured in parks and nature preserves while living there. The trails and our inclinations led us down to this special spot, on adjoining Army Corps of Engineers land.

Crowned by a massive white oak, the bluff is a collection of diabase boulders and uncommon plants overlooking the creek. 

One of those uncommon plants that makes this spot distinctive is resurrection fern (Pleopeltis polypodioides), all curled up and dried out on one of the boulders. Resurrection fern is an epiphyte, meaning it builds itself largely out of water and air, pluse whatever few nutrients collect on the rock it clings to from fallen leaves. Unlike most plants, this fern's leaves can dry out during droughts, then rapidly rehydrate after rains.

The only other place I've seen resurrection fern in Durham is on a similar but much larger bluff, where the Eno River just to the north encounters a mass of diabase rock and takes a sharp turn to the right, called Penny's Bend. I sense a kinship between these two bluffs, botanically and geologically. They could be called Big Bluff and Little Bluff, reflecting the respective size of the watersheds they are in.

(Up here in Princeton, NJ, with the same piedmont geology as Durham, a similar relationship can be seen between the big "Roaring Rocks" boulder field in the Sourlands and the boulder field in Princeton's Herrontown Woods, where the boulders are smaller and the water tends to chuckle and murmur rather than roar. These geologic features, too, are composed of diabase rock that resisted erosion through 200 million years.)

Looking up, I spotted another unusual native plant, eastern mistletoe (Phoradendron leucarpum), growing high on a tree branch. This one's a hemiparasite, meaning it extracts some sustenance from the tree but also has green leaves to make some of its own energy.

Other trees nearby also had dense balls of vegetation high up in the branches, but they weren't mistletoe. Those are witch's broom--a dense cluster of twiggy growth that is the tree's response to a pathogen or other irritant. Cynthie pointed out they are common on hop-hornbeam, a tree I hadn't seen in a long time and had been wanting to run into.

Turned out we were in the midst of a grove of eastern hop-hornbeam (Ostrya virginiana), growing along the edge of the bluff. (Upon returning to Princeton, I found some of these with their distinctive bark growing in Autumn Hill Reservation.)

Another tree nearby, judging from the leaves on the ground, was swamp chestnut oak (Quercus michauii). Paul Manos of Duke University calls these "sun leaves," meaning they are leaves that had been growing higher in the canopy and thus received a bigger dose of sunlight. They're smaller, thicker, and with sharper lobing than the more shaded leaves below.

I found more online about sun leaves and shade leaves, in a post by Gabriel Hemery:

"If there is some sunlight however, even a little diffuse light (see below), then a tree makes the most of it by producing shade leaves lower down in its canopy. Shade leaves are larger and thinner than normal sun leaves, and often appear a darker green (they contain more chlorophyll). They also have half as many stomata than sun leaves, or even fewer, and so have a lower respiration rate. They can react quickly to brief bursts of sunlight and dappled shade.

Shade leaves can turn into sun leaves and visa versa; providing that the change is gradual. This is something that a gardener moving a plant outside that has been grown indoors or in the greenhouse, must be aware of. When a plant is taken outdoors, place it first under shade and gradually over several days increase its exposure to bright sunlight." 

It would be interesting to know if pine needles, like those high up on this shortleaf pine, also vary according to how much sun they receive. 

During my eight years in Durham, plus many return visits over the years, I've found many special places along Ellerbe Creek. They could be as simple as a native azalea leaning out over the creek, or as complex and improbable as a roadside embankment packed with more than 100 native species of piedmont prairie. A few have been tragically destroyed, but it's heartening to return to those that persist, their charms sustained, their uniqueness unshattered by a rapidly changing world. These pockets of stability give my soul something to lean on.

Training Deer to Eat Invasive Plants -- Japanese Knotweed

Here's a story and a partially forgotten concept from ten years ago that a commenter on this blog helped me reconnect with. The concept has to do with actively training deer to eat invasive plants. Thanks to Mark Nowotarski of Stamford, CT for reminding me of this concept, and adding his own interesting twist.

Deer manage our landscapes with their appetites. Whether it's your unfenced yard or the local nature preserve, deer largely decide what can grow and what gets eaten down. Introduced plant species can become invasive if they are left uneaten by finicky deer, thus allowing them to proliferate rapidly and overwhelm native flora. Wouldn't it be great if we could train deer to eat invasive species, and thus restore balance to the landscape? 

Ten years ago, I wrote about two ways to potentially train deer to eat invasive species. One is to cut down invasive shrubs along the deer paths and let the stumps resprout, thus presenting the deer with tender new shoots to nibble on. As the deer (hopefully) grow accustomed to the taste and texture of the invasive's new growth, perhaps they would begin eating older foliage as well. 

It's also possible that the deer respond to visual cues. If we repeatedly cut back an invasive shrub, deer may assume other deer have been eating it, and chow down. Deer have reason to revisit a shrub again and again. By eating its foliage, they stimulate the shrub to replace the lost leaves with new ones, much as we do with basil and other vegetables in our gardens. Making their accustomed rounds, deer essentially farm the forest for fresh foliage.

Though we experimented with this at Herrontown Woods mostly with winged euonymus, Mark reports some success with recruiting deer to browse a patch of Japanese knotweed in his backyard:

"I've seen a similar phenomenon where I live in Stamford CT. We have a little bit of woods in the back yard where deer tend to congregate. There is a dense stand of Japanese knotweed down by a small stream. A few years ago, I started foraging the tips of the knotweed in the spring and noticed that the deer continued to browse the knotweed through the summer. Every time the knotweed would send out new shoots, the deer would browse the tips. At first they just browsed where I foraged, but in the past few years now they have expanded the browsed area and are actually beating back the knotweed. If you see any knotweed browsing in your area, I'd love to hear about it."

He sent photos and more text to illustrate:

"About 4 years ago, I noticed that the deer on our property had started browsing the spring shoots of a stand of Japanese knotweed. The knotweed grows down by a swampy stream and has been there for at least 30 years. Each year the deer have browsed the stand more intensely." 

"When the knotweed throws out side shoots after the initial browsing, the deer browse the tips of the side shoots. When the side shoots throw out secondary side shoots, the deer browse the tips of those as well. This continues through the summer."

"The knotweed in the browsed area is kept to about 3 feet tall and is very sparse. Abundant sunlight falls on the forest floor and there has been a substantial increase in the plant biodiversity of the browsed areas." 

"This includes the sprouting of native plants, such as Sassafras albidum (Sassafras) and Impatiens capensis (Jewel weed). I found the I. capensis particularly surprising since this is normally heavily browsed by the deer."

"The deer only browse a portion of the knotweed stand. If a knotweed shoot reaches full size, it’s not browsed. Nonetheless, each year the deer have been browsing a larger and larger area. They originally browsed just an outside edge of the stand where I used to forage knotweed shoots in the spring, but last year they started hollowing out the center of the stand." 

"Based on your experience with winged Euonymus, this leads me to suspect that it might have been my initial foraging that led the deer to continue the browsing. It would be interesting to forage some unbrowsed knotweed in the spring and see if the local deer continue."

Thanks again to Mark Nowotarski for these photos and descriptive text of the interesting dynamic between deer and the patch of invasive Japanese knotweed in his backyard. In our experiment ten years ago with winged euonymus, we found that invasive shrubs ultimately grew back, likely due to our having cut so many that their myriad young shoots overwhelmed the deer's mild interest in their foliage. We also didn't think to try focusing our cutting close to deer paths. 

Anyone managing a sizable nature preserve will soon grow weary of cutting invasive shrubs only to have them grow back. Treating a freshly cut stem with a thin film of systemic herbicide, using a Buckthorn Blaster, is a targeted, minimalist way of actually making progress in a woodland choked with invasive species. 

But especially for the vast majority of woodlands that go unmanaged, the concept of training deer to eat invasive species has appeal. I'm looking forward to harvesting some young shoots of Japanese knotweed this spring, as an experiment. Having trained the deer in his backyard to eat this highly invasive plant, Mark may train me to eat it as well. Testimonials like this one suggest the young shoots are quite tasty. Research the how, what, where and when before giving it a try. Mark recommends sauteing with butter.

Update 1.30.25: Just came across another of my posts from ten years back, entitled Paradox Lost, or, Less Irony in the Woodland Diet, offering a third way to get deer to eat invasive plants. If there are mint-flavored sprays that discourage deer from eating ornamental plantings, maybe there's a flavor of spray that would encourage them to eat invasive plants. 

Seeking "Lingering Trees"--Some Hope for Ash and Beech Trees

Most people attentive to nature are aware that Princeton has lost nearly all of its native ash trees over the past decade, and is now poised to lose its native beech trees as well. These are only the most recent losses due to assorted introduced insects, nematodes, and diseases against which our native trees had not evolved resistance. Also gone from the canopy over the past century are American chestnuts and American elms, with bacterial leaf scorch also taking a toll on red and pin oaks. As additional organisms enter the country due to an appalling lack of biosecurity, other species are threatened. 

What is there to do other than mourn, and mourn again, with each new wave of devastation? 

One answer to that question may be: Keep an eye out for "lingering" trees. It would be easy to assume that all our native ash, not having co-evolved with the Emerald ash borer (EAB), would be equally defenseless as the introduced larvae eat through the cambrium, cutting off the tree's circulatory system. But an initiative in Ohio has shown this not to be entirely true. Jennifer Koch, a research biologist with the USDA Forest Service, has been leading an effort to find "lingering ash", that is, mature ash that survive while others all around them succumb. Some ash that she and others have found have natural defenses that kill 20-45% of the larvae that bore into them. A very few trees kill 100% of the invading larvae. 

A very watchable video features Jennifer Koch, and also Holden Arboretum's Rachel Kappler, telling the 
story of ash lost, lingering ash found, and the effort to increase resistance among lingering ash through research and breeding programs.

One particularly impressive slide in the presentation showed how the resistant trees are able to stop the invading larvae before they do damage to the tree. 

 
Here are some of my notes from the video:

• Ash wood is/was used for bats and guitars
• Native ash species in our area: White, green, black, pumpkin
• 300 million acres of black ash-dominated forest in Minnesota could be lost (apparently no other tree species can survive in those wet areas)
• green ash is an important riparian buffer species in the plains states, hard to replace
• The lingering ash are found individually or in clusters, e.g Swan Creek, Oak Openings Park, near Toledo, 108 out of 11,000 had healthy canopies. Two specimens had no evidence of attack. Most resistance is partial, but resistance can be increased through breeding
• greenhouse tests can reduce the amount of land/labor needed for field tests
• resistance is inherited, though uneven

A central point these researchers make is how very limited is the area they have surveyed for lingering ash--only a small area near the Ohio/Michigan border. They call for similar initiatives in other parts of the country. 

That's where we come in, as keen or at least intermittently keen observers of the landscape through which we walk. It's important that any tree we believe to be lingering be a mature, wild tree--not a cultivar in a planted landscape--and that it be a tree that has weathered the massive wave of EAB over the past ten years, remaining green while others nearby have succumbed. Photos of lingering ash, and one story of their discovery, can be found at this link. 

A brief mention of the various species of ash: I associate white ash with higher ground and grander specimens found or once found around town. Green ash are less statuesque and more associated with wetter ground. Black ash I think of as growing, or having grown, in swamps, such as at Rogers Refuge in Princeton. The Ohio initiative is apparently finding most success with resistant green ash, though the video mentions lingering white, green, and black ash having been found in NY state.

In addition to the info below, there's also anecdata.org--a platform where citizen scientists can set up reporting initiatives.

This keeping an eye out for "lingering" ash can also be applied to other imperiled species in our area. The Ohio researchers request that people report lingering American beech, hemlock, and American elm as well. 

Related posts:

Emerald Ash Borer in Princeton

Beech Leaf Disease Sweeps Across Princeton

Holden Arboretum Studies Resistant Beech and Ash Trees

An Homage to Princeton Ecologist Henry Horn

This homage to ecology professor Henry Horn was written after the very moving memorial service for him in the Princeton Chapel nearly six years ago, and has just been rediscovered, sitting patiently in the draft folder.

Though March 14 is memorable as Einstein's birthday, I'll remember it too as the day we lost Henry Horn, the beloved Princeton professor and naturalist whose many-layered ways of studying the natural world and communicating it to his colleagues and the larger community made him unique in all the world.

I knew him primarily from nature walks--those he led in various Princeton preserves and those of mine at Herrontown Woods that he would show up for and add so much to, often with his wife and botanist, Betty. On these occasions, his sonorous voice would convey warmth and clarity as he shared his deep knowledge of geology and forest ecology.

At the May 5 memorial service under the vaulted, ornate canopy of Princeton University Chapel, a colleague called Henry "the heart of the Department of Ecology and Evolutionary Biology." For me, he occupied a similar place in the community. Talking to him, I felt no sense that I was on the other side of a wall that some professors construct between themselves and the outside world. I found in Henry Horn no sense of division or Other, no Nassau Street of the mind dividing ivy league from community.

After the service, I mentioned this to one of his younger brothers, and asked how this combining of academic achievement and commonality had come to be. He said that, though later Henry would go to Harvard, their parents had insisted that their children attend public schools, where they were around people of all walks of life. Henry's mother had had a hard life growing up, and there was always something to restore humility when their heads got too big.

At the service, we learned that Henry's father had been a minister, whose various positions had taken the family from Virginia to Georgia for four years before moving north to Boston. I asked him (the younger brother) if the family's southern roots might have something to do with Henry's easy connection with people outside academia. I explained that I had lived in North Carolina for eight years, and had felt in many ways like I had found home. It was the habit of people there to consistently acknowledge the existence, the humanity, of others. Known or stranger, it made no difference. He immediately knew what I was talking about, and said this aspect of the south is not sufficiently appreciated in the north, where people tend to stereotype southern sensibility in negative terms. 

While many scientists studying nature conduct their research in distant locales, Henry found value and meaning in local woods and fields. He was quoted at the service as saying, "You don't need to travel far away to study nature". His treasuring of the local could be considered prescient, given the university's recent efforts to connect more with the community.

Henry was one of the older among nine or so siblings, in a house they filled with the collected gleanings of nature. Most were brothers, but the oldest was a sister who would return from school and share with the others everything she had learned that day. That sharing was described as a university education in and of itself.

Most of us who knew Henry a little or a lot knew him as warm, insightful, infinitely curious about the world, whimsical. It was a surprise, then, to find out that he had a competitive side, and had an inner toughness, as when he stoically endured the brutal welcome dished out by a gang of boys when his family first moved to a neighborhood in Boston. He and his brothers ultimately gained the new neighbors' respect and became friends with some.

As a kid, he had a passion for tinkering with watches and electronic devices, taking them apart and putting them back together again. This tinkering led during his years as an assistant professor to what he would later call his "tenure machine," a device for assessing forest canopy and shade tolerance that led to an influential book that in turn led to his gaining tenure.

His scientific inquiries seem frequently to have led to art, and vice versa. As can be seen in a wonderful video portrait of Henry, entitled Boy Wonder Emeritus, he got ideas for art from the patterns he saw in his photos of canopy, and the carved wooden animals he would pull out of his pocket to use for scale in his nature photography served as ambassadors to help convey science to youth.

He was a force for cohesion on campus, providing advice and constructive feedback to all who sought him out. Resisting the academic temptation to withdraw into this or that silo of specialized study, he showed up for a wide range of talks. He also somehow avoided the human tendency to focus questions or comments on perceived flaws or gaps in a presentation. He instead would ask supportive questions that suggested new avenues of inquiry, and sometimes would even help clarify for a less than articulate speaker what he or she had been trying to say. His aim was to bring out the best in others, not tear them down.

As Samuel Barber's Adagio for Strings filled the chapel, above and all around and in our hearts, I wondered if Henry Horn's passing represented also the passing of an era when the work of biologists took them outdoors, rather than into a lab. A colleague of his assured me that much research in the EEB department still takes professors out to the field. 

Thinking of that era, I remembered my own mentor, Herb Wagner at the University of Michigan, 20 years Henry's senior. It was the 1970s, botany classes were overflowing, environmental legislation had bipartisan support. Wagner's office was filled with specimens of plants and butterflies, gathered from near or far. Classical music on the local public radio station would waft out into the hallway, interrupted only by a few minutes of news at the hour. We were still innocent of any awareness of climate change, and populations of invasive species and deer had yet to explode. Distrust of government and scientists had yet to be injected deep into the national psyche.

Having learned about Oswald Veblen, the renowned mathematician and conservationist who preceded Henry Horn at Princeton by sixty years, I can't help but see Henry as Veblenesque in many ways. Both reached beyond academia to connect with the community. Both were deeply drawn to the land. It was Veblen who worked to acquire the land that later became Henry's beloved Institute Woods. Both worked hard to support and advance others' careers. And when they faced physical challenges--for Veblen it was partial blindness, for Henry it was a handicapped child--their response was to invent devices that would help not only in their own situations but for others facing similar challenges.

The Princeton University obituary for Henry serves as a good continuation and elaboration upon what I offer here. A couple quotes:

In 1991, he led the University into a new era of interdisciplinary environmental research as founding director of the Program in Environmental Studies. He transferred to emeritus status in 2011.

“He had an original mind and was so caring. He saw patterns in the natural world that others often overlooked"

Henry lives on in many ways, including some online videos:

Henry's nature walks
https://www.princeton.edu/news/2018/07/16/nature-walks-henry-horn

Skunk Cabbage
https://vimeo.com/278156799

Mockingbird
https://www.facebook.com/watch/?v=632608590467273

Comments on Henry in memorium
https://blogs.princeton.edu/memorial/2019/03/henry-horn/

Touring a New Preserve in Plainsboro--Bulk Farm Nature Center

My friend James Degnen called me up recently, and with his deep baritone voice invited me to explore the Bulk Farm Nature Center--a new nature preserve in Plainsboro, NJ. A former tree nursery, the preserve has cherry blossoms in the spring, leaf color in the fall, and lovely vistas through the winter. Note: The back portion of the preserve, with trails that reach the Millstone River and a bald eagle nest high in a tree, is closed from January through July, to avoid the bald eagles' nesting activity. 

Acquired in 2008, the property took fifteen years to prepare for public use, opening in September, 2023. Some soil contamination was found, likely requiring a lengthy bureaucratic process of remediation.

Though the 80 acre preserve is easily accessed at 179 Cranbury Neck Road, you'll need to navigate past the unusual name. It's called a Nature Center, but there's no building, and "Bulk" refers not to any particular aspect of the preserve, but instead to the family that once owned the farm. Like those housing developments that are named after whatever natural feature was destroyed during the course of development, this nature preserve may ironically be named after a building demolished after the land was preserved. Similarly, the gravel road bisecting the property is called Homestead Drive, leading presumably to a homestead that no longer exists.

A trail map is available online. 

James explained that the soft gravel of the Homestead Drive is to be avoided in favor of the mowed trails winding back along either side. 

Though lacking any topography, the preserve's trails take you through a varied landscape with broad vistas across meadows. At first, the meadows are solid with goldenrod, but deeper in some of the native grasses--broomsedge (as in "Andropogon Trail") and purple top--become more prevalent. 

The map conveniently marks where benches can be found, built to last well into the next century. 

The groves of nursery trees prove yet again that it's easier to plant a tree than to sell it.

Most trees are small, but somewhere towards the back right of the trail system we encountered an extraordinarily large river birch.

Towards the back of the preserve, you reach a gate that will be closed and locked for the first seven months of the new year. Bald eagles nest in a tree near the river, and are not to be disturbed. 

It not being January yet, we were able to hike all the way to the back of the preserve, and see the very impressive eagle nest. The tree appears to be a red oak fighting a bad case of bacterial leaf scorch. 

Beyond the eagles' nest, the trail ends at a tranquil spot along the Millstone River. James said the water continued to flow through the long drought this fall.

On the way back, James partook of a pet pleasure--releasing milkweed seeds to the wind.

One curious plant you may encounter in the expansive meadows is this shrub with red stems. Though multiflora rose is a highly aggressive, thorny invader of our natural areas, it is sometimes slowed down by a disease that spread to NJ from the midwest. Called rose rosette disease, the disease stunts the leaves of the multiflora rose and turns the stems red, particularly in sunny locations. 

A gray birch's bark doesn't flake like the bark of a white birch. Both of these birch species are native further north.

The hike took about an hour. Thanks to James for making me aware of this new preserve a fifteen minute drive from Princeton. James' rich baritone voice, by the way, is in demand for doing voice-overs, and we collaborated back in 2019 on a film project in which we recast The King's Speech as a call for action on climate change. 

Past adventures up Plainsboro way:

The Plainsboro Preserve is Anything But Plain

Kayaking Up the Mighty Millstone Marsh

And another tree nursery turned nature preserve, in Lawrence Township: 

The Lost Meadows of Maidenhead Meadows

Whither the Migration of Monarch Butterflies?

Though the number of butterflies in general was radically down this summer, I still saw the occasional monarch. Some appeared frantic. Were they searching in vain for a mate? Other times they'd pause on a flower to take a long drink of nectar. Sometimes I'd just see a flash of orange out of the corner of my eye. No other butterfly can match a monarch's nimble power in flight. The number of sightings, maybe ten in all, wasn't much changed from previous years.

Their longterm prospects, though, are very much in question. Chip Taylor, who has tracked migrations as closely and for as long as anyone, says that monarchs as a species will survive, but their fabulous migration will not. Last year's overwintering numbers on Oyamel fir trees in the mountains of Mexico was the second lowest ever recorded. Resilient as the monarchs are, it's hard to imagine the delicate dynamic of migration surviving the rapidly increasing disruptions of climate change.

Yes, climate has changed in the past. It's said that, before humans started altering the atmosphere, the earth experienced a progression of ice ages every 100,000 years or so. During the last ice age, glaciers extended south almost to what is now NY City. What we have now is change at a speed far beyond the capacity of species to adapt, as our machines pour a massive overdose of carbon dioxide into the atmosphere.

In a blog entry this past August, Taylor explained how extremes of weather can affect the monarchs' capacity to build numbers over the summer and migrate back to Mexico in the fall. Extended heavy rains in early summer can delay egg laying. Warmer temperatures in September and drought in October can impede a fall migration historically aided by cool winds out of the north. What we got this year was hot and dry, with three months of drought and warm weather extending into mid-November. That's a radical departure from anything I've ever witnessed.

Each year towards the end of October, I start looking for news about the migration south to Mexico. The first headline I found confirmed my suspicions: "This fall's monarch butterfly migration through Texas doesn't look promising." Then, finally, a report on-site at the roosting grounds in Mexico. Though a few had been straggling in over the past few weeks, the first largish group of 2000 monarchs wasn't reported until Nov. 21. In past years, monarchs would predictably arrive en masse in the first week of November. Then, after the monarchs had settled into their roosts, the Biosphere Reserve would be opened to tourists mid-month. This year that opening was cancelled, stranding those tourists who had traveled far to witness a unique example of nature's splendor. This is not the only destination being compromised in a world being heated in part by global tourism. There are different ways to show love for nature. Touristic love, which I was a part of in the past, becomes more ironic by the minute.

The radically dry, warm weather we've experience this fall has a lot to do with the increasing instability of the jet stream--high winds out of the west that normally feed us a steady stream of contrasting weather, but can get blocked and diverted north or south, causing weather systems to linger indefinitely. The jet stream is driven by the difference in temperature between the tropics and the arctic. As the arctic heats more quickly than lower latitudes, the temperature gradient is reduced and the jet stream becomes more malleable. 

Consider the extraordinary ambition and brilliance of the monarch butterfly's eastern migration. Huddled overwinter in the mountains of Mexico, its numbers head north in March, then each succeeding generation--usually four total--fans out from Texas to harvest the richness of flowers and milkweed foliage from the whole eastern half of the U.S. and even up into Canada, before somehow knowing how to navigate all of that embodied richness back to their little hideout in Mexico. Over the past million years, the distance flown would have contracted during ice ages, then expanded as the glaciers withdrew. I think of the monarch migration as akin to a rubber band, stretched northward by the supply of nectar and milkweed, then contracting back down to Mexico for the winter.

The vast territorial expansion each summer is surely dependent on numbers. Otherwise, how will the monarchs find each other to mate as they spread out across the continent? Though much different in behavior, the passenger pigeon was also dependent on big numbers. Its demise, more than a century ago, was due to radical habitat change and a wanton harvest and slaughter that Aldo Leopold described as "trigger-itch." Now, our itch is to take photos, and our intention is to preserve. And yet, we watch as the collateral damage of a machine-driven economy accumulates.

A post on the Monarch Watch Blog describes the Symbolic Monarch Migration that school kids in Mexico, the U.S., and Canada take part in. Kids in Mexico send paper monarchs to kids up north in the spring, and vice versa in the fall. Monarchs ignore country boundaries. They are telling anyone who takes time to listen that our interests don't stop at the border, what we do affects people and nature far away. 

One halcyon autumn day when I was a kid, walking across the broad lawns surrounding Yerkes Observatory in Wisconsin, I was astonished by the sight of countless thousands of monarchs flying above me. There was a thrilling collective energy to their flight, not dutifully unidirectional towards the south but instead more like a dance. They seemed to feed off of each other's proximity and energy--an uncanny mix of whimsy, skill, and determination. 

If the great migration were to be lost, monarchs would still persist in pockets further south, but they wouldn't be the same monarchs we've known and loved. Here's a post on how the loss of migration's rigors would change them.

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.