Little Bog of Horrors

I find the urge to explore bogs and boggy habitats difficult to resist. Other people avoid them, which gives me space to be alone. They’re mucky, which is often a fun and challenging substrate underfoot. They contain unique species, which I find fascinating. They are full of life. And they offer surprises.

On an unseasonably warm late October day, I found myself poking around the edges of Little Messer Pond, an approximately 27-acre pond in Katahdin Woods and Waters National Monument, Maine.

Photo of pond and surrounding vegetation. Pond is at lower right. Short shrubs and sedge at lower left. Pines, spruce, and large line pond.
Little Messer Pond
Photo of pond. Trees line the pond in the middle and background. Short shrubs form the pond's border in the foreground.
Little Messer Pond

While exploring the pond’s northern flank, on a shelf of sphagnum peat that cups the pond’s shore, I found several purple pitcher plants (Sarracenia purpurea), one of the most iconic bog species in this area. The purple pitcher lives an uncommon, carnivorous lifestyle for a photosynthesizing organism. Pitcher plants supplement their growth by capturing small animal prey, typically insects. Unlike Venus fly-traps, however, which ensnare prey using a trigger-like mechanism, pitcher plants use a passive, gravity-driven process. Their leaves form bell or cone-shaped bowls that fill with rainwater. The top of the each leaf has a flaring lip lined with nectar glands to attract insects. If a hapless insect falls inside, downward pointing hairs resist its escape attempts. 

Several pitcher plants growing out of reddish-colored sphagnum moss.
Purple Pitcher Plant

Pitcher plants can’t move, so they have unsurprisingly indiscriminate tastes. To cite just one example, a study from Newfoundland documented 12 insect orders serving as prey in pitcher plants. Prey eventually drowns in the pitcher’s water where enzymes as well as inquilines (microorganisms adapted to live in the pitchers such as midge larvae, nematodes, bacteria, protozoa, and rotifers among others) break down the trapped prey, releasing nitrogen and phosphorus for the plant. Purple pitcher plants, in particular, seem to be particularly rich in inquilines, hosting at least 165 different species across its range. Pitchers are habitats of their own making and their adaptations allow them to live in nutrient poor soils where competition from tall plants in minimal.

Looking at the pitchers on the edge of Little Messer, I found ants, beetles, flies, dragonflies, various bits of unidentified insects, and a sludge of the leftovers in their bowls.

They’d eat me if I were small enough. 

GIF from Little Shop of Horrors. Plant says "Feed Me!" while Seymour looks at it.

None of the prey was unusual or unexpected until I stumbled upon a curious sight—a spotted salamander inside a pitcher.

Spotted salamander floating in a pitcher plant's bowl.

I was taken aback by the sight. I had never seen something like this before, and I remember exclaiming “What the?” even though I was alone. Was this a big payday for the plant or was the salamander only a temporary resident?

Small vertebrates are exceedingly scarce as a prey item for purple pitcher plants. In the scientific literature, I couldn’t find much documentation of it. A study from Massachusetts documented red-spotted newts as a food source for pitcher plants. A more recent study from an Ontario bog found that spotted salamanders are a potentially rich prey for pitcher plants. (One of the researchers leading that study described his sighting of a salamander in a pitcher plant felt like a “WTF moment” so I guess I wasn’t alone in my surprise.) In August 2017, researchers at that study site searched the contents of 144 pitcher plants. They found, as expected, mostly insects but also several recently metamorphosed spotted salamanders. In August 2018, they investigated 58 plants and found three spotted salamanders. The physical condition of the salamanders varied. Some were in an advanced state of decay while others were lively and were able to swim to the bottom of the pitcher when disturbed.

Plenty of uncertainty surrounds pitcher plants and the importance of small vertebrate prey to them like salamanders and newts. No one has yet tested what might attract a salamander into a pitcher since a salamander has to climb up to get into one. If the salamander can escape, then pitchers could be a refuge for salamanders who have recently emerged from the water onto the land. Perhaps salamanders are attracted to the pitcher by small insects visiting to feed on the plant’s nectaries. Their apparent capture could be random too, although, dead salamanders apparently break down quickly inside pitcher plants so maybe their true rate of capture is greater than anyone realizes.

I wonder if it might happen only in places with the right combination of habitats. Purple pitcher plants typically (but not exclusively) grow in nutrient poor bogs, places that don’t always support breeding populations of spotted salamanders. Adult spotted salamanders migrate en masse during spring to vernal pools where they breed. They may also use permanent ponds for reproduction as long as those don’t contain fish, which eat salamander eggs and larval salamanders. Newts, in contrast, breed in a greater variety of wetlands including ponds and lakes that contain fish. 

At the Ontario study site, pitcher plants grow on bog islands in permanent and fish free ponds where spotted salamanders gather to breed every spring. This seems to provide a combination of habitats that increase the likelihood of pitcher plants capturing salamanders later in the year when the juvenile salamanders metamorphose and begin their terrestrial lives. Little Messer Pond, in contrast, is home to fish, snapping turtles, and presumably other salamander predators.

A salamander or newt, even a juvenile, is a significant catch for a pitcher plant. A newt of about 500 mg of dry mass contains about 5 mg of nitrogen, which is several orders of magnitude more than an ant, a pitcher’s most common prey. That’s enough nitrogen to increase the probability of the plant flowering the next summer. If the salamander I saw had indeed perished in the pitcher, maybe it’ll dignified in death by a marvelous pitcher plant flower next summer.

Pitcher plant flower. Petals are fleshy. Flower is radially symmetrical.
In my area, purple pitcher plants flowers appear in early summer.

Pitcher plants are wonderfully adapted to secure nutrients and survive in habitats that most plants cannot tolerate. If they’re lucky enough to capture something as large and nutrient rich as a salamander, then their physical structure can hinder escape. Their acidic water (often lower than pH 4 by mid summer) can weaken salamanders through electrolyte imbalance. And, the water within them might contain compounds that inebriate or paralyze small prey. 

The fate of the salamander that I found remains unknown. I returned a week later with the intention of relocating it, but I could not find it despite my best efforts. Although I can’t be sure, I think it is unlikely that I missed it since the boggy area with the pitcher plants isn’t large and the pitchers are easy to locate. If it were still alive, perhaps it fled to the bottom of the pitcher upon my approach. However, if it were still in the pitcher after seven days, then it should’ve been dead. Did it escape the trap that so many other victims of pitcher plants could not? I wish I knew the end of this story—a drama of uncertainty, survival, life, and death.

A Most Impressive Bog

Some people who know me well poke fun at my penchant for exploring mucky places. At one national park where I worked as a ranger, it took a few years of turnover among the seasonal staff before their friendly prodding about a short lecture I once gave on the differences between bogs, fens, and muskegs died away.

I suppose my fascination with wetlands began on camping trips when I was young (probably no older than eight or nine years). In those good ol’ days of the 1980s my cousins, me, and any temporary campground friends we found spent hours alone exploring a “swamp.” It was little more than a shallow, cattail-filled ditch at the end of one of the state park campground’s cul-de-sacs, but armed with dip nets, fishing nets, and plastic buckets, we pulled more than a few frogs, tadpoles, and crayfish out of it, and sometimes a leech or two off of us.

Although I couldn’t articulate it at the time, I now understand that I was drawn to that place because it seemed so alive. I’ve never outgrown the urge to slog into habitats where I feel like other life forms envelope my whole being. A trial-and-error bushwhack is a small burden to pay so that I can experience that feeling again, which is how I found myself shoving through tangles of spruce and larch last June.

In a broad lowland a few miles south of Patten, Maine lives a most impressive bog. The difficulties I experienced getting into the bog were far surpassed by the beauty one experiences in a rarely trammeled landscape. Crystal Bog is the most spectacular bog I’ve ever seen.

Photo of peat bog with pond at center left, yellow-colored sphagnum moss at center, and red-colored sphagnum at right. Horizon is lined by sparse conifer trees.
Google Earth image of Crystal Bog area. Scale at lower right marks 3000 feet.

Getting into Crystal Bog (also known as the Thousand-Acre Bog) is not an easy task—a fact I discovered when I first explored it in 2020. No trails enter the bog proper, and the adjacent ATV trails only skirt the extensive swampy thickets that surround it. Choosing the wrong route is easy in such habitat, especially on overcast days when clouds obscure the sun and any hint of which direction might be north or south.

I don’t carry a GPS device or a smart phone, so I navigate via compass when vegetation is too thick and landmarks too obscure to provide orientation. During my attempt to access Crystal Bog in 2020 I rode my bicycle a little too far on the ATV trail that cups the north side of the wetland, started south at the wrong place, didn’t utilize my compass often enough, and bushwhacked much farther than expected or necessary. With those lessons learned, however, I felt better prepared to avoid the thickest muskeg and swampiest areas to reach the open bog more easily.

I locked Rocinante to a sturdy tree once I located a good starting point…

photo of bicycle leaning against a tree in dense vegetation

…and set off through the trees.

thick forest with ferns, shrubs, and tall trees filling the entire frame

Crystal Bog is part of a large wetland complex. On every side of it, streams meander through forested swamps and sedge-filled fens. The sphagnum peat lands at the center of this complex was my destination, though.

After 20 minutes of travel (a remarkably short time span compared to the two hours of bushwhacking I needed the previous year), the forest began to transition into a more open woodland. Sphagnum moss and low-growing ericaceous shrubs became common and spindly black spruce and eastern larch were the only trees.

open forest with tall conifers and thick, low shrubs in understory

Shortly after, I reached the open expanses of the bog proper.

bog with widely scattered small trees

As I moved from swamp to muskeg to sphagnum bog, I moved progressively into harsher habitats, at least from a botanical perspective.

Bogs are a type of peat-land that generally get water from aerial precipitation rather than flowing surface or ground water. Sphagnum thrives here. The tannins and acids released by sphagnum lower soil pH to levels inhospitable for most plants. While a bog’s edges might be richer in minerals and productivity due to ground or surface water flow, the sphagnum-dominated areas in and around its center offer very different conditions. The pH at Orono Bog near Bangor, for example, progresses from 6.6 (a pH you find in milk) at the forested edge to 3.8 (a pH approaching that of grapefruit juice) at its sphagnum-dominated center. Since the pH scale is logarithmic, rather than linear, this difference represents almost a 1,000-fold change in acidity.

close up view of deep red sphagnum moss

Sphagnum moss

As more sphagnum grows on the surface, it buries and compacts previous generations to form peat. Decomposition is also hindered by the low oxygen conditions found in the bog’s supersaturated soils. But, sphagnum is really good at growing on top of itself. In this manner, sphagnum begets sphagnum. Under the right climatic conditions, sphagnum bogs can sustain themselves for thousands of years and peat accumulations can grow many meters thick. Peat also preserves a botanical record of the plants that lived in the bog and the pollen that settled on it, a paleontological record on present and extinct animals that died within them, and even an archeological record of the people who utilized these places.

On top of this wealth of partial decay exists a living veneer. Minute gradations in topography and drainage create micro-habitats for the plants that are adapted to the bog’s stressful conditions. The higher above the bog’s water table, the more oxygen can diffuse into the soil and the more O2 is available for plant roots that need oxygen. Relatively few plant species survive in bogs compared to nearby forests. Yet those that do are often abundant.

Larch and black spruce in bogs receive ample sunlight, have access to plenty of water, and experience little competition from other tall plants, but the peat enveloping their root systems offers little to sustain their growth. Small-statured trees in a bog may be many decades old, while growing little more than the height of an average adult person. At the Orono Bog, some 7-foot tall spruce trees were found to be about 100 years old. (FWIW a tree, I think, cares not for its appearance, only its ability to reproduce.)

island of small-statured black spruce surrounded by dwarf bog plants

These small-statured black spruce (Picea mariana) may be many decades old.

Ericaecous shrubs such as Labrador tea, bog rosemary, and laurels survive in bogs only where their shallow roots remain perched above the flooded peats and sphagnum. Yet, although bogs are classified as wetlands, summertime drought can cause drastic lowering of the water table. The thick, leathery leaves of these plants might help them retain moisture under those conditions.

flowers of Labrador tea. Flowers are white and clustered at the top of the stem.

Labrador tea (Rhododendron groenlandicum)

flowers of sheep laurel. Pink flowers are clustered at a node in the stem.

Sheep laurel (Kalmia angustifolia)

Orchids tap mycorrhizal fungi to overcome the lack of nutrients, a trick utilized by the ericaceous plants as well.

flower of grass pink. Flower is pink and bilateral in symmetry. The lower lobes are bright pink.

Grass pink (Calopogon tuberosus)

Other bog plants evolved means to capture nutrients from animals. Bladderworts capture prey in small sacs attached to their thread-like underwater leaves. When a tiny zooplankton contacts sensitive hairs on the outside of the bladder, it triggers the bladder to inflate. The sudden action sucks in water and the hapless prey. The plant then absorbs its nutrients.

bladderwort flower. Single yellow flower at top of thin stem.

Bladderwort (Utricularia sp.)

Sundews ensnare small insects using sticky secretions on the ends of glandular hairs on their leaves. An insect alights on the leaf and becomes stuck. The hairs and the leaf margins then slowly fold over and envelope the insect. The leaf hairs also release an anesthetic to stupefy the prey as well as enzymes to dissolve its soft tissues.

Round-leaved sundew (Drosera rotundifolia). An unlucky insect is trapped on the leaf in the right photo.

Pitcher plants use specialized leaves to create a basin of water. Insects that fall into the basin, aided by downward pointing hairs on the inside of the leaf’s rim and numbing secretions, are slowly decomposed by bacteria and possibly plant enzymes that live in the water. Specialized cells at the bottom of the pitcher absorb the insects nitrogen and other nutrients.

Pitcher plant (Sarracenia purpurea)

I paused often as I wandered through the bog to marvel at the tenacity and beauty of the life around me. I also marveled at the lack of a human presence. The ability to experience a landscape that wasn’t overtly altered by people was a special treat, even in one of the least populated U.S. states.

Maine is lushly vegetated. Forest covers a greater percentage of its land than any other state. That forest, though, is heavily manipulated by people—by a timber industry that often harvests trees before they reach age 50, by a warming climate, by tens of thousands of miles of roads, and by invasive species. But human-caused changes are not limited to the land. Off the coast, the Gulf of Maine is one of the fastest warming bodies of water in the world. There is virtually no Atlantic cod fishery because cod haven’t recovered from the devastation of overfishing in the 20th century. Ditto for Atlantic salmon, which hang on by a thread. Places where evidence of humanity’s heavy hand is absent or at least minimized are difficult to find even in parks such as Acadia, Baxter, and Katahdin Woods and Waters.

Bogs are often overlooked at best or viewed as wastelands to be “reclaimed” for agriculture or mined for peat at worst, but they rank among the worlds most important habitats, especially when we consider their ability to capture and sequester atmospheric carbon. Like old-growth forests, peat is a non-renewable resource since we humans lack the patience and self-restraint to harvest it at sustainable levels (please buy peat-free soil products for this reason).

While the area surrounding Crystal Bog is full of roads, early successional timberland, potato fields, homes, and small towns, this bog remains remarkably unmarred. It is one of the few places in modern day Maine that would be recognizable to a Wabanaki traveler from the 15th century. In the middle of Crystal Bog, it’s easy to let your mind drift to a place where the world is well. This is an illusion, I realize, but one we all must escape into every once in a while.

bog landscape. Small pond sits at upper right. Yellow and red sphagnum moss are at center and left.