NANTUCKET AT NIGHT
Fireflies in heat, cormorants in trees and herds of garter snakes
This week, The Nantucket Independent

introduces a summer series entitled

Night Hikes. This series will help you

to discover the island's natural world as the light of day fades into nighttime.

At dusk, while some Nantucket critters

bed down for the evening, the night shift of birds, reptiles, amphibians, animals,

fish and insects emerge, looking for food, love and vocal chord exercise.

Stars come out, planets glow and sparkle and as the air cools, a whole

new world opens up.

Less destination-oriented and much

more of a what's-out-there guide, we will also share with you what there is to

see, hear and feel out in Nantucket's

harbors, saltmarshes and ponds. Isaw snakes - three of them - probably garter snakes, the most prevalent snake on the island. And I saw all of them in the span of three minutes while I was walking a trail near Stump Pond. It's the same trail I'd walked scores of times during the day, and saw not one slithering reptile.

But here I was at dusk - fog wafting through the swampy forest between Almanack Pond Road and the west side of Stump Pond - trying to grab what obviously did not want to be held. It's quite possible that these three snakes had been huddled together in one spot under a log or leaf litter to conserve and share body heat.

Snakes are cold-blooded creatures, or ectotherms, that use their environment to regulate their body temperatures. Therefore, I probably would have found them more easily during the day after that sunning out in the open. They're fairly easy to spot. At less than 24 inches, garter snakes have one to three body-length yellow or red stripes with checkered blotches between them. They have an appetite for frogs, toads, insects and earthworms and generally live near, but not in, wet ecosystems - hence my sightings near the swamp.

Just prior to my snake encounter, I had seen five or six double-crested cormorants roosting in the trees at the edge of Stump Pond and about the same number of great egrets sharing the same branches. The egrets I'd seen here before, but cormorants, which I thought were primarily ocean birds that preferred coastal bays, harbors, estuaries and even open ocean, were a surprise, especially since their webbed feet probably made it difficult for them to grasp the branches upon which they were perched.

PHOTOS BY PETER B. BRACE/The Independent

A little further on, after finding my way out onto Almanac Pond Road, I walked south to the aforementioned pond and found it full, likely because of the rain we had about 10 days ago.

The pond itself is a kettle hole pond, one that is neither spring-fed nor a basin filled with stream or river water. Island settlers named it "Almanack" because they could use its contents, or lack of, to approximate the time of year. At the time I was there, July 10, it was also full of frogs, chugaruming not in unison, but seemingly taking turns.

Opposite the pond's east side is a short, steep trail leading up to a meadow that, on a clear day, reveals an excellent view of the swamp and pond when one is sitting on someone else's shoulders.

Back down at the pond, it is dark enough for me to see a few fireflies skittering over the water and lighting up the grasses around its edges. Not really walking with any clear loop or destination, I head back to where I came out of the swamp and go west up into a meadow being restored by its owners, the Nantucket Islands Land Bank.

It is now dark enough that the fog is behaving ghost-like, sending wisps of salty vapor-laden shades out over the undulating barren hills. Walking up one, I flush a woodcock with its long, narrow bill. I then glimpse three deer bounding into the scrub oaks, visible only by their shapes and flipping white tails.

Before I lose my sense of direction, I walk back the way I came and down onto Almanack Pond Road to go toward Polpis Road, all the while rufous-sided towees calling their trademark "drink-your-teeeaaa" and gray catbirds alternately meowing and mimicking other birds, most of which had the sense to say goodnight about an hour after I started exploring at 7 p.m.

With the growing darkness has come an explosion of lightning bugs, fireflies for you aficionados, and more than I ever expected to see on Nantucket.

Walking out onto Windswept Cranberry Bog, I am treated to what looks like thousands of defective Christmas tree lights all blinking out of synchronization. But for the male Pennsylvania firefly - actually a beetle and not a fly - each pulsing his greenish-yellow abdomen on and off every two to three seconds, this bog, forest and field lightshow is a tightly choreographed dance for two: the male lighting up his backside in hopes of hooking up with the flightless female swooning and blinking her backside on the ground.

The firefly's bioluminescence produces no heat and is generated by light organs on its belly. The bioluminescence is made up of several layers of reflector cells with one layer of lightproducing cells infiltrated with nerves and air tubes. The firefly's body pumps oxygen into the air tubes, which oxidizes the light cell product luciferin into oxyluciferin using a catalyst enzyme called luciferase that releases light energy. The randy firefly doing aerial acrobatics for his love interest on the ground, controls the intensity of his glowing behind by constantly adjusting the amount of air flowing through his tubes.

The result: a natural pyrotechnics show visible nearly every night in July and into early August.

I literally could have sat there all night in the cooling fog watching this ground lightning were it not for the mosquitoes and horseflies that found my exposed skin a lot more tantalizing than a bunch of glowing beetles.

How to Get There Find this nightly summer experience by getting out to the Windswept Cranberry Bog, the first right after the turn for Wauwinet Road coming from town and the first left after the turn for Quidnet Road coming from 'Sconset. Also a fiveminute walk from each road's respective Nantucket Regional Transit Authority stop along the 'Sconset via Polpis Route. From the parking area, hike south on the wooded trail to reach the bogs and then discover

your own path. I