I tried to sit in a position where my shadow would not cover the pitcher plant. My aim was to observe the plant under the most normal conditions possible. This particular pitcher plant, one of many on this quaking bog, was in total sunlight throughout most of the day. As I shifted my weight around to find a better sitting position the peat bog underneath shook like a bowl of lime jello. Each time I moved little solid green waves could be seen running across the green and red tinged peat bog.
Watching a northern pitcher plant sounds like boring business, no doubt about it. I was very curious about how this carnivorous plant worked. I knew ants and other insects were attracted by nectar and the red striped color of the plant. I also knew that insects fell into the center of the plant from the brim. Once there, fast acting enzymes would desiccate the ant and slowly allow nutrients from the insect to feed the plant. Sounds good in a text book, but just exactly how did the insects fall into the death pit?
As I was sitting there I marveled at the niche that the pitcher plants, and other carnivorous plants like sundews, had filled. This inhospitable environment cannot host normal plants; special adaptations to habit these areas are required. Bogs are incredibly acidic. The acidity really impacts the availability of nutrients. Most plants could not survive here. Oh sure there were a few like peat moss, and some more complicated plants like cranberry and bog rosemary. There were even a few Labrador tea and leather leaf bushes around. Most of these acid loving plants have special adaptations to garnish nutrients; shallow rooting, an overdeveloped crown on the small trunk above the water line, lenticels, or some other adaptation that could extract nitrogen and other nutrients from the environment. Some plants have even adapted to waiting for the next rainfall to fill their nutrient requirements. The carnivorous plants evolved with bogs over eons and eons of time to find a way of capturing small animals, i.e. insects, so that nutrients could be extracted from their carcasses. That’s incredible when you think about it. Plants that eat animals! Wow!
Not all carnivorous plants use the same strategy. Pitcher plants use simple mechanisms enlisting attractants like nectar and a place for insects to fall into and get quickly consumed by powerful enzymes. Plants like the Venus flytraps have closing leaves that move quickly to close on the prey. Sundews, another group of carnivorous plants, capture tiny insects with a very sweet sticky substance that is emitted from tiny tentacles that snare their prey. All of these processes are miracles of evolution!
Given no insects had arrived during my first hour of waiting I decided it would be okay if I put my finger in the plant and felt around. The inside felt mildly slippery; kind of a waxy texture. I reasoned that the area was so slippery that the ants and other insects just slipped right in when searching for the nectar. But that didn’t quite make sense to me. If it was that good at catching insects then it had the potential to really make a large dent in their population. Looking into several pitcher plants I could see a few insects, but certainly nothing that approached an entire ant colony. I would just have to wait and see.
The sun was getting higher in the sky and the bog was feeling pretty steamy. As one who appreciates arctic weather this wasn’t exactly my cup of tea. But then a breeze started to whip up and some clouds overhead provided shade now and then. The change in weather also, probably coincidently, brought a few ants to the pitcher plant. For the first half an hour or so there were just a few and they seemed to have no trouble negotiating around the lip of the plant without falling in. I couldn’t tell exactly, but it looked as if they could get close enough to the liquid within the plant’s tube to retrieve some of the nectar. Interesting, I thought, these ants were seemingly capable of outwitting the carnivorous plant. Within an hour the plant was swarming with black ants. I looked at other pitcher plants and they were all doing business at a record clip. In another fifteen minutes the pitcher plants were so busy it looked like the mall on the day after Thanksgiving. I did see a few ants get knocked into the liquid by other ants, also reminiscent of black Friday shopping! It wondered if this is how they captured their prey, accidental drowning. It just didn’t seem plausible.
While all this was going on, I lost track of the weather. There was no heat to distract me so why would I be paying attention? And wouldn’t you know it, without warning the sky became very dark and a very fast and sudden downpour was upon the bog. I was picking up my gear to head back to my truck when as fast as the rain shower started it stopped again. To make matters even stranger, the sun was out again almost immediately. I guess that’s why they call them sun showers.
I looked back at my pitcher plant. Holy smokes! The ants were slipping all over the place and sliding right into the vat of doom! Evidently the waxy surface on the brim of the leaf could be negotiated when it was dry, but when you added water the viscosity changed entirely and the ants scurrying around just couldn’t get or keep traction.
I watched the ants fall into the pitcher plant for a few minutes and noticed that the horde of ants was diminished. There was no where near as many ants at this point in time to slide into the slippery abyss. I wondered if they were reacting to the demise of their fellow ants. Somehow they had the capability to recognize the danger and move away after a few dozen ants slipped to their viscous demise.
The mystery solved I could now find my way back to my truck and amble towards home. There is absolutely no question that others had observed this phenomenon before me, but in those days, before the internet, sometimes self observation was faster than a day long trip to a decent library.
As I headed home in my old truck the soft springs bounced me up and down on the unimproved roads. It reminded me of the rolling, up and down, motion of the quaking bog. Perhaps I would stop for breakfast on the way home in a nearby village. I thought I might enjoy something that hadn’t been recently captured and dissolved. Pancakes with maple syrup sounded good!
Written for www.wildramblings.com in May 2009.