Tuesday, 13 December 2011

Something a little different

Since I have 3 exams between now and Friday morning, I haven't really had time, nor will I have time for a few days, to post something exciting/about actual birding/the winter list/etc. So instead, I thought I would delve into something that I wrote last semester for my Nature Interpretation course. It was a creative writing assignment about some phenomenon of nature, so naturally I picked the spring migration of salamanders. Its a bit of a long read, so if you're short on time bow out now!


            The day has finally arrived. After restlessly checking the weather forecast for weeks, it appears that tonight will be absolutely perfect. Despite looming end of the year projects and finals, I cannot pass up on an opportunity like this to see one of nature’s greatest spectacles.
                As I drive in my car through the countryside towards my destination, my mind begins to wander to the night that is in store. Eager with anticipation, I do my best to keep my car at a reasonable speed. With the daylight quickly surrendering to the dark gloom of the evening, my spirits continue to rise.
                It isn’t long before I arrive at my location – one of the last remnant areas of true Carolinian forest in this part of Ontario. Stepping out of my car, I can hear the clear, high song of a Black-capped Chickadee calling to a potential mate – “Choose meeeee!!!!” – as a second chickadee repeats the phrase, but outdoes the first with a higher song. Love is in the air!

vernal pond in Carolinian forest

                The darkness encroaches while the sweet smell of the rain-soaked ground beckons me. At a temperature of 8 degrees Celsius, the evening is bordering on mild. At last, old man winter is loosening his grasp. Once again, the two male chickadees call in awkward harmony, this time in the distance as I make my way down the muddy trail towards my destination. While the chickadees are music to my ears, this is not the reason that I am visiting the area.
                Tonight is the night that I hope to observe the march of the salamanders. Every spring for thousands of years, these denizens of the deep woods stir from their subterranean haunts when the warm rains of late March penetrate through the layers of ice and snow and touch their bodies. Spurred on by their biological clock and need to reproduce, the salamanders emerge from their burrows to make their way to their favourite ponds. There, they will reproduce by means of an obscure mating ritual before returning to the hills.
                While these ponds are filled with ice-cold water at the time, this is not to last. By mid-summer, all but the deepest vernal pools will dry up, leaving any potential progeny to bake in the hot sun. “The chill, edge-of-spring night with abundant rain, final snowmelt, saturated earth, and an overflowing vernal pool is measured against the inevitable day of blazing sun, great heat, and desiccating winds in July or August, when the last film of water in the deepest pool depression becomes transformed into windborne vapour.” (Carroll, 1999). The salamanders have to move NOW, even with layers of ice on many of the ponds, so they can reproduce and give their aquatic offspring a chance of surviving this furiously ticking clock.
                I arrive at the first pond and my spirits slowly begin to sink. Instead of the usual cacophony of Spring Peepers and Western Chorus Frogs, the only sound I hear is the steady pitter-patter of the warm rains on my ball cap. Perhaps I have arrived too early in the season, with all the amphibians still deep in their winter retreats? Peering into the murky depth of the wetland I can see no sign of amphibians so I moved on. Hopefully I will have more success at the next pool.  Spring is not only about migratory birds, a Painted Turtle basking on a sun-drenched log, or the first flowers poking through the ground – it is also about snow banks, late season blizzards, icy water, and sleet. As David Carroll (1999) mentions, spring is in good measure a time of waiting within a constant, incremental advance. With our tendency to think that the world revolves around us, we humans become rather impatient with its turnings. Of course, the earth simply spins and follows the same path, year in, year out, with the resulting life becoming so attuned to these cycles.
                My thoughts are abruptly halted when the beam of my flashlight catches something shiny in front of me on one of the hillsides. There it is – the first salamander of the spring season. Adorned in his clown suit with a big grin on his face, the chubby Spotted Salamander is steadily crawling across the path, his hormone-filled body only stopping once it reaches its destination. I may have seen hundreds of this beautiful species in the past, but after such a long absence I must get reacquainted. Carroll (1999) expresses this beautifully: “As in the past, the meeting of my expectant search image with reality is a striking revelation, undiminished by remembrance or repetition. To see these living things anew is to know them anew”. The salamander freezes instantly – not from the cold rain or quickly disappearing patch of crusty ice he is standing on, but from the sudden intrusion of a blinding light into his world. He does not move for 2 minutes, but finally the urge to reproduce is much too strong and he continues blundering down the hillside towards the vernal pond.

male Spotted Salamander on his way to a breeding pond

                As I walk, my mind begins to wander about the fragility of this ecosystem. From where I am standing, all my flashlight beam can catch is dense forest, small ponds, and a large expansive marsh. However, even in this relatively pristine place, I cannot help but notice the steady drone of cars driving by the near road. While at first glance this sensitive Carolinian forest is secure, it is a small size and is surrounded by farmland and encroaching development. It is a little disheartening to think that this is one of the largest strongholds of Carolinian forest in the county. Even with all the sensitive species abounding in this beautiful place, it will not take much for a developer to get permits to knock down the trees and drain the wetlands. The diversity and tranquility can be traded for the bustle of a neighbourhood with much too little effort. Even if the vernal ponds, ecosystems that are crucial to a wide variety of terrestrial and aquatic organisms, are protected with a relatively large buffer zone of 25 or 30 meters, this will not be enough to protect the salamanders. Spotted Salamanders, along with the closely related Blue-spotted and Jefferson’s Salamanders, are together in the family Ambystomatidae (mole salamanders). As their name suggests, much of their year is spent deep in subterranean crevices, rotted out tree roots, and other ancient passageways. Ideal vernal ponds are few and far between in forests such as these. Often, a single ephemeral wetland will be the sole breeding ground for all mole salamanders within a kilometre or more of the pond. Studied have shown that up to 50% of the salamander populations are usually found at least 100 meters from the vernal pond so this 25 meter buffer zone will only protect a tiny fraction of the entire population (Petranka, 2000). As Carroll (1999) points out, “leaving a narrow band of buffering vegetation around an encircled vernal pool has been likened to protecting a bird’s nest and the tree it is in, while eliminating the surrounding field and forest habitat required by those who fledge from the nest”.

                  I arrive at my favourite ephemeral pond for the 4th time this spring. The first visit was on a warm, rainy night in late January with the temperatures hovering around the 10 degree Celsius mark. While enticing, this early rain was not the alarm going off inside of the salamander’s internal alarm clock, so naturally I found nothing. The second night was similar, this time in early March. Again, it was too early and all I found was the bloated body of a Green Frog that had not survived the winter, or perhaps, mistakenly ventured out on the warm night in late January. Three nights ago I had visited the pond, pleased that much of the ice had receded after the 3 days of the 10 degree weather we had experienced. However, the rains did not arrive so the salamanders stayed put. But tonight, this is the night.
                My beam picks up an incredible sight in one corner of the vernal pond, where the sides slope up to at least a 30 degree angle and the water is not too shallow. The bodies of at least a hundred Spotted Salamanders, tightly woven and intertwined, are writhing together in a mesmerizing ball. It is almost dizzying to watch as the salamanders move with fluid and precision that, if I did not know any better, would have made me believe they were fully aquatic. Occasionally one salamander wriggles free, propels himself to the surface with arms tucked to his sides, gulps a quick breath of air, and rejoins the captivating mass of solid salamanders.
                These giant mating balls are some of the most fascinating biological phenomena I have ever laid eyes on. Starting out with 4 or 5 solitary males, they are soon joined by many others, with finally a few large females, stomachs swollen with eggs, joining the bunch. This mating ball is essentially some sort of foreplay though it is not understood exactly why it takes place (Petranka, 2000). Eventually, pairs break off to the side of the writhing orb – pairs intent on love-making. The male drops multiple spermatophores – tiny,   jelly capsules with a miniscule packet of sperm on top - and attempts to lure the female to straddle one and pick it up with her cloaca. Once she does, the salamanders separate with the female looking for a quiet place to deposit her eggs. After the closeness of the mating ball and subsequent courtship, the actual event of mating is surprisingly impersonal. 

female Spotted Salamander depositing eggs

                After what seems like hours pass while I observe this incredible phenomenon, I leave the wetland. The air has a certain chill to it and the rain has stopped. Ever since I had arrived at this wetland, I would occasionally catch a glimpse of a Spotted salamander slip into the edge of the black water to join in the activities. Now that the rain has paused and the air has become frigid, the hurried frenzy of the mating ball has started to dissipate. While watching the few remaining males, twisting together desperately in the wee hours of the morning in hopes of attracting one last female, I start to think of the blissful ignorance of these animals. Here they are, unchanged for thousands of years, performing the same ritual each and every spring. Yet just over the hill may loom the first bulldozer, ready to destroy this beautiful display of life for good. I only hope, however unrealistic that hope may be, that these salamanders are able to carry on this incredible behaviour for years to come.

“In wilderness is the preservation of the world”
 -Henry David Thoreau

Carroll, D. 1999. Swampwalker’s Journal: A Wetlands Year. Houghton Mifflin Company, New York, NY. Chapter 1.
Nash, R. 2001. Wilderness and the American mind. Yale University Press, London. Chapter 5.
Petranka, J. W. 1998. Salamanders of the United States and Canada. Smithsonian Institution      Press, Washington, D.C., USA.

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