Thursday, May 20, 2021

17 Year Cicadas Rise to the Occasion

It's a good thing the lawnmower refused to start on Monday, because on Tuesday morning, carrying our aging dog down the patio steps to the backyard, I saw that the 17 year cicadas had emerged overnight, and had used the long grass stems as a perch upon which to molt. 
They clung to the stems motionless, their new exoskeletons hardening, their wings drying in the morning sun. Were those brand new red eyes looking at me, or at everything all at once? Beside them was the empty shell of their former selves--the nymphs that had lived the past 17 years underground in patient immaturity, chowing down on tree roots. 

The night before, my daughter had heard the rustlings of leaves as she sat on the front steps. As dusk turned to dark, the million Magicicada march to adulthood had begun.

The immature nymphs had been preparing for this moment for some time, plotting their upward mobility, each having dug a tunnel to the surface. We had encountered them for weeks prior, slicing through their tunnels while digging holes, exposing their excavations while moving wood. I imagined them all stationed some distance down their tunnels, facing up, sensing the temperature of the air above them and the ground around them, ready to respond with fascinating unanimity to a cue only they could feel. 

I decided to bone up on them. What was wikipedia like 17 years ago? That which once was ridiculed, like "made in Japan" or "made in China," has become the information equivalent of what Deep Blue became in chess. Miraculously, it has evolved into a remarkably accurate and thorough source of information, encyclopedic, as it 'twere. I was sure people would find a way to mess it up. But no. Great to be wrong sometimes. Could this capacity to filter out the worst inclinations of humanity be applied to other areas of the internet?

Scrolling down through the wikipedia page on "periodical" cicadas, my simplistic assumption that 17 year cicadas emerge everywhere in the same year was blown out of the water. There are many different "broods" in the U.S., each with a different timing. In any given year, there's a brood of 17 or 13 year cicadas emerging somewhere. Virginia has seven different broods. New Jersey has three. Princeton's cicadas are part of the "great eastern brood," which extends from New York down to Georgia and out to Illinois. Is it called great because the brood extends over such a large geographic area, or simply because Princeton is included? We don't know. 

One thing the wikipedia entry doesn't explain is why I would have documented a considerable emergence of periodical cicadas in Princeton in May of 2017. The closest emergence in the wikipedia chart for that year was in North Carolina.

Can we eat them? I love this short article in the Smithsonian, which gives tips for gathering and cooking. I didn't take it personally when the article states that "Females are preferable for their protein-filled abdomens, while males offer little substance." The author of the article, someone named Twilight, must have enjoyed crafting sentences like "Marinating live bugs in Worcestershire sauce also helps weed out guys." It got me to wondering if I, too, would collapse if slow-cooked in vinegar, while the ladies all around me grew more tender by the minute.

One thing's for sure, this will be the most photographed generation of 17 year cicadas ever. For the next month or two, while their bus-with-wings bodies fill the air outside, they'll also be zipping around in posts, texts and tweets.

There's lots to read about why their periodicity (13 or 17 years) is in prime numbers. And why kill so much time underground before emerging en masse? It certainly makes it hard for predators like cicada killer wasps to expand their numbers sufficiently to take advantage of the sudden abundance of prey. Kill time or be killed--that's the logic.

And very interesting to read that moles do well the year prior to the emergence, as the cicada nymphs grow in size in preparation for their coming out party. Might the many moles feasting on growing cicada nymphs underground have had something to do with all the digging up of lawns by foxes, skunks, and raccoons reported last fall?

Trees are going to take a hit, as the female cicadas start cutting into twigs to lay their eggs. I remember seeing twigs littering the ground seventeen years ago, leaves still green, particularly under oaks. And I remember wondering what kind of world those cicadas would find when they next emerged, given the radical changes in climate we've set in motion. Thus far, not so much change in New Jersey. We've been lucky so far. I worry, though, as the mass combustion continues, and our deceptively shallow atmosphere fills with the invisible, transformative gases--the exhalations of an economy at odds with the nature we depend upon. More personally, it didn't even occur to me, seventeen years ago, to wonder if I'd be around for the next emergence. Now, that distant rendezvous is harder to take for granted. Cicadas aren't the only species playing a numbers game. It would feel better, this personal passing of years, if we weren't taking many of the glories of nature down with us. Whatever Happened to Forever is a one minute play I wrote that deals with this, at 8:49 in this video

This awareness of future endings stirred me to live this moment in cicada history more intensely. Eating dinner on the patio, I became aware of a prickly sensation on my legs. Normally, I would have brushed them off. Instead, wishing to experience their emergence fully, I let them climb. People have given me various nicknames over the years--"plantas", "the plant man"--and it's starting to look like even the insect world thinks I'm a tree. 

At one point, around the time I was polishing off my last shish kabob, I had six of them climbing the mountain of me. They had trouble with my hair, with most falling off before reaching the deceptive summit of my knee. But one was successful in making a nearly full ascent, climbing up to my shoulder, then ascending my neck and cheek. Only my sideburn and hairline proved unsurmountable, at which point it fell off, only to begin the climb again. 

After dark, I went out back to have another look at the lawn. A few more had climbed the grassblades. As they emerged from their shells, they showed two black spots just above the eyes, like dark eyebrows. But the unmowed lawn proved not to be the really big show.

Things really got interesting when I happened to look among the perennials. This purple coneflower looked like a Christmas tree with cicada ornaments, in all phases of metamorphosis. 

There's a bit of acrobatics to their molting. They do a slowmo backflip out of the shell, then bend up and grab their old skin, clinging to the shell of their former selves as they pull the rest of their abdomen out to hang free. Then it's a matter of unfolding and slowly expanding the wings, which look like little nubbins at first. 

A lot can go wrong in this stage. Some had wings that didn't grow out right, with one or the other being shorter and misshapened. 

When you google the cicadas as food, a study comes up warning that cicadas can accumulate a lot of things during their 17 years of underground munching, one of them being mercury. I don't know if it's a big concern. Many of our foods have traces of mercury. But it's worth wondering whether deformations in cicadas during molting is increasing as we continue to dig chemicals out of the earth and spread them around.

Another cicada had the bad luck to attract one of the slugs that was also seen climbing up foliage last night.

Many were having trouble finding a good place to climb. One even hitchhiked into my room and tried to climb into this blog post.

By morning, the cicada ornaments on the purple coneflower "tree" had darkened. Their wings and exoskeletons will slowly harden over the next few days. Though the coming din may grow tiring, it's still pleasurable to read that the adult males gather in something akin to a men's choir to sing to the females. Examples of nature's abundance, more rare now, are stunning to behold. We're in the midst of one now. 

Saturday, May 15, 2021

Native Azaleas Bloom Again at Herrontown Woods

This spring, Herrontown Woods had its first big show of native azalea blooms in many decades. They were all on one bush, but it was a start. I counted the blossoms--25, which is 22 more than the grand total from five years ago. A friend who grew up in Princeton told me that wild azaleas had once been a common sight in spring. What caused them to disappear? The answer is more deer and more shade. 

The pinxter azaleas are not the only species that has languished in the deep shade of the forest. Shadbush and hearts-a-bustin' have also been marginalized. It took some years of exploration to realize that they were still there, surviving in a miniature state, a foot or two tall, deprived of sunlight, nibbled down by deer. 

One of the first to be spotted, during a morning walk five years back, was a spindly pinxter azalea that had somehow managed to grow three flowers, like a weak SOS signal coming from a distressed ship. When the shrub failed to bloom at all the following year, I responded by digging a small sideshoot from the base and planting it in the preserve's Botanical Art Garden, where we maintain the equivalent of a forest opening. Bathed in sunlight and protected from deer browse, the azalea has thrived in a way it never could beneath dense trees.

Growing next to the azalea in the botanical garden is a shadbush, so named because it blooms when the shad are migrating up rivers in early spring to spawn. It, too, is finally getting an opportunity to grow to maturity for the first time in decades. 

Another species seldom encountered along the Princeton Ridge--only two have been found in Herrontown Woods thus far--is the pagoda dogwood. It's alternate leaves (arising not in pairs but instead singly on alternating sides of the stem) give it another common name, alternate-leaved dogwood, and also its latin name, Cornus alternifolia. The flowers aren't that showy--pompom-like clusters reminiscent of the more common silky dogwood--but the pagoda-like shape of the branches is striking. Hopefully we'll be able to witness that as this one grows up in a sunnier location than is available among the dense trees of the woods.

Other size-disadvantaged woody species being brought into the botanical garden to get out of the shade and deer browse are hazelnut, persimmon, and hearts-a-bustin'.
A native chestnut tree is also checking out its new home in the botanical art garden. The chestnut has been disadvantaged in today's forested preserves not by limited size but by the lingering chestnut blight disease that nearly eliminated them from the continent a century ago. This one is 15/16th native, crossed with an asian species that hopefully conferred immunity. Unlike the other woody plants mentioned in this post, the planted chestnut is not a local genotype.

In the early days of the Herrontown Woods preserve, there was a chestnut tree still growing along the yellow trail. The blight doesn't affect the roots, so it essentially sent the species "underground." Chestnuts persisted to some extent by sending up suckers that would grow to ten or twenty feet before succumbing to the fungus, at which point yet another sucker would be generated, to meet the same fate. Eventually, I suppose, the roots ran out of energy to keep sending up suckers.

Butternut, too, has been laid low more by introduced disease than by size limitations, and will be getting a home in the botanical garden. 

Add to these woody species all the sun-loving wildflowers that have an even harder time surviving in our tree-dominated preserves, and it becomes clear that what we have created at Herrontown Woods is a place where disadvantaged native species can have a chance to show their stuff. This opportunity for upward mobility was once built into natural systems, back when megafauna and fire served to set back the trees, when deer were kept in check by predators, and long before invasive species stifled with their overwhelming growth. We love our trees. For many people, trees are a symbol of nature itself, and yet it's important to remember that the less lofty species are also part of nature, and have as much claim as large trees to a place in our preserves. Thus, "plant a tree", for all its resonance and popular appeal, is more relevant to our streets than our preserves when it comes to actions we can take to heal nature and nurture diversity.

Four additional native azaleas were added to the Botanical Art Garden last year, rescued from deep latency and finally given a chance to grow. In time, they could make for a really big show, and it all started with a floral SOS along a trail. 

Saturday, May 08, 2021

Bennett Place: Hidden Beauty Amidst the Barrens

Herein, Princeton Nature Notes travels down the long sweep of the piedmont to Durham, North Carolina, to visit past discoveries and persistent miracles. 

The evolution of a plant lover can lead in unexpected directions. In my case, my fascination with plants first evolved from vegetables (loved for their utility and productivity) to roadside weeds (loved for their beauty amidst neglect, blooming unnoticed as the world speeds by). When we bought a little house with a beautiful backyard garden, my love shifted to perennial borders, with their showy poppies, irises, and delphiniums. But beauty for beauty's sake lost its meaning after awhile. My love shifted to native plants that had evolved within a community of plants, all deeply connected and intertwined back through time. Some of these could be showy, like a forest glade full of trillium and dogwoods. But this love extended to other congregations of native plants whose beauty was not in overt display but in their diversity and uniqueness. Some of these remarkable congregations--I discovered a few while living in Durham--were so subtle as to appear barren from a distance. 

This field, long ago preserved in the Ellerbe Creek headwaters to commemorate the largest surrender of the Civil War that took place here, looks empty and a bit threadbare. The stump, though, is of a shortleaf pine whose rings numbered 150--a surprising age for a smallish looking tree. But what possibly could have made this a favorite place for great Duke University botanists like Blomquist to botanize, nearly a century ago? 

Walk out into the field, look down, and you may see what appears to be a rash of red spots on the ground. 
A closer look reveals a tiny plant about to open a tiny flower. It's a carnivorous sundew, with sticky leaves that catch and consume insects. 
And these blotches of green may look like pesky dandelions in a weedy lawn, 
but in fact are a special native plant called Arnica. How many other places had I seen these plants growing, in Durham or anywhere else in all of my travels? None. This place, called Bennett Place for the farmer who owned it back when the Confederate and Union generals met, can appear barren and yet is botanically rich. 

Surprisingly, the field's uniqueness and rich diversity has survived through the centuries because its soil is so poor. Not poor in the sense of having been exhausted through extractive farming. This soil is unfarmable by nature, a sort of soil classified as "Helena" or "Appling", like concrete when dry, yet also somehow sustaining of sphagnum mosses and plants like the sundew that would normally be found in bogs. Perhaps a few farm animals once grazed there, but frustrated farmers looked elsewhere for better land to tear up with their plows, and so this field and its special flora remained undisturbed. 
The poor soil has also discouraged the more aggressive plant species, allowing more fragile-looking plants to survive. These are what I call the "plants of peace", the modest flowers that likely bloomed at the feet of the generals and their soldiers 156 years ago, during those momentous days of negotiation in April, 1865. 
This one, dwarfed by my fingers, looks like a miniature bluet.
And next to this field of miniature flowers
is a forest that too is deceptive. It may look like what once was an old farm field that grew up in loblolly pines, 

but many of the trees have the thick platy bark of a shortleaf pine--more associated with places where fire once swept through. 

Holding their own, for now, among younger trees are the "old guard" of craggy shortleaf pines and post oaks that once comprised a more savanna-like open forest, their thick bark adapted to survive the ground-level fires that would sweep through, sparked by passing trains. 
Large expanses of low-bush blueberries, another species stimulated by periodic fire, are more evidence of this past, more open landscape. The fires no longer sweep through, and the decay-resistant needles and oak leaves lay thick on the forest floor, smothering what likely had been a diverse growth of wildflowers. Who knows what long-slumbering seeds might sprout if a prescribed burn was done here.

Twenty years ago, the site manager at the time, a man named Waters, made me laugh when he admitted to being baffled by us plant lovers. How, he wondered, could a group of people stand for an hour out in the middle of a barren-looking field, talking animatedly about what we were seeing at our feet?

Well, it's a long evolution. 

Thanks to Johnny Randall of the NC Botanical Gardens for his patient count of tree rings. Johnny was also the discoverer of the sundews, which he found by ... looking down.

Saturday, May 01, 2021

(Mostly) Native Flowers of Late April

This post documents some of the many native flowers to be found in late April, from deep woods to front yards. 

A medium sized shrub called Fothergilla, or witch alder, is having a good year in our front yard, though it's not found growing naturally in our local forests. 

Clouds of white in the woodland understory this time of year could be flowering dogwood, 

but blackhaw viburnums, central Jersey's most common native Viburnum, have also just opened up, dotting the understory with their large congregations of small pompom-like clusters of white flowers. 

Sometimes a closer look at an assemblage of white flowers reveals a flowering crabapple tree, as in this photo. Not completely sure as yet that these flowering crabs are native. 

Providing some contrast with the predominating white is the redbud, here seen at the "barden" at Herrontown Woods, where a forest opening allows it enough light to thrive.

On the forest floor, the most common wildflower is spring beauty, 

Rue anemone is an improbably delicate and fairly numerous presence along nature trails.

Trout lily should feel welcome to bloom more than it does, but seems content to mostly form carpets of sterile single leaves, few of which mature into the two-leaved plants that bloom.

By now, the bloodroots have passed from blooming to fruiting stage. 

Nice to see some young bloodroots popping up through the leaf litter.

Some native spring ephemerals occur only in the less historically disturbed lands along the Princeton ridge, like Herrontown Woods. Wood anemone grows distinctive leaves with five leaflets. 

Update: Sadly, some plants have been removed from this post due to reports of plant theft in Herrrontown Woods. Uncommon plants tend to be adapted to particular soils and hydrology, so are unlikely to survive transplanting. Even if it were legal, it's a bad idea. 

Meanwhile, in the botanical art garden (Barden) next to the parking lot in Herrontown Woods, Rachelle planted some Virginia bluebells, which are very rarely seen growing naturally.
Wood phlox is another flower in this category, native but rarely seen in the wild. 

There are a couple nonnative wildflowers that are particularly noticeable blooming now in wild areas. This mustard, which I remember from travels in the english countryside, where whole fields were colored yellow by its blooms, was found growing along the gas pipeline right of way at Herrontown Woods. As plant lovers and dreamers, we sometimes envision a pipeline right of way becoming a corridor of native flowers and grasses. Reality tends to defeat this sort of dream, as the linear right of ways instead play host to the most tenacious of invasive plants--Phragmitis and mugwort.
Garlic mustard, a less tenacious invasive plant but worth pulling, has tasty leaves in early spring. A biennial, it blooms the second year, becoming less tasty as it matures. In this flowering stage, I pluck the flower heads, then pull the whole plant out of the ground, roots and all, the idea being to prevent it from producing seed and thus reducing future sproutings.