From The Mag: The Underappreciated Underworld Of Amphibians

The Kingdom of Spring

Amphibians at play, uncensored and uninhibited

words:: Leslie Anthony

The late March woods in Haliburton, Ontario, are quiet and sullen. Morning’s blue sky has succumbed to obdurate grey, drawn like a shade from one horizon to the other, painting leafless hardwoods and crusty snow in black-and-white monotones.   

The thick ice crowning a large beaver pond is barely free of the shore, but water glistens darkly in the few places it has pulled back. Scents of pine and cedar tumble through the air, but the trees themselves look frozen in time. The afternoon pall is an allusion to life-fled-the-land, but a warm south wind smells of rain and I’m pretty sure that later, all hell will break loose. 

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That night in town, people crowd into McKeck’s to watch NHL Stanley Cup playoffs on the big screen. As in most of Canada, springtime here means hockey, maple syrup, and a long-awaited respite from the cold. But while we humans measure spring’s air of renewal in cultural terms, some animals are tied to a more stringent metric: it’s the only time of year an individual might see another of its kind. Naturally, such encounters engender a certain kind of urgency—one that can also get biologists excited. Maybe too excited: while Don Cherry analyzes another punch-up on Hockey Night in Canada, I’m supervising an orgy near Lake Kashagawigamog.  

Swept on strong gusts, the predicted rain sifts through the forest, coalescing as large drops that tumble from naked branches. Muffled noise in the leaf litter melds with the rain and a growing cacophony from the pond; in the dark, they’re the kind of sounds that make your skin crawl. The night is alive and the ground around me moves. No Hollywood special-effects tech could marshal what I track in my headlamp. 

 

Wood frogs like this one are among the first amphibians to breed in the spring. Photo: Patrick Moldowan

 

 

Thousands of glistening amphibians have risen from the quiescence of the forest floor. Blind with purpose, they zig-zag towards the pond in drunken clusters, bouncing off each other like surprised billiard balls. This night it’s the Cold Crew—denizens of earliest spring: burnished wood frogs, tiny spring peepers, striking yellow-spotted salamanders and, in greatest abundance, glabrous blue-spotted salamanders. What this slippery mélange lacks in diversity is made up in sheer numbers: there are more of them within a metre of where I crouch than the average person sees in a lifetime. 

Given their cryptic habits, the best way to appreciate the secret world of amphibians is when the animals converge in spring to play out the drama of breeding, a prodigious burst of ritual advertisement, frantic courtship and furtive mating—like spring break in Daytona Beach without the booze. As time marches on in the Haliburton woods, so will the parade: chorus frogs, American toads, red-spotted newts, gray treefrogs, leopard frogs, green frogs, and bullfrogs will all aggregate in time-honoured sequence through April, May and June, an exquisite choreography rooted in the deep history of eastern North America’s rich amphibian fauna. As a graduate student studying these migrations, it was a dance I came to love. 

This is the first good rain of the breeding season, and I watch mesmerized as animals converge from every direction, swarming indifferently over snow, ice, rock and wood. Internal switches are firmly locked onto phase one: Must Get To Water. Put something in front of them, they go over it; put them in something, they climb out. Water, when it’s reached, becomes both sanctuary and medium for phase two: Must Mate. In my light, startled frogs leap into the darkness, while at the pond’s edge salamanders appear to sense the weight of their impending biological destiny; pausing briefly, they take one last look around before plunging beneath the ice. 

No Hollywood special-effects tech could marshal what I track in my headlamp.

Most terrestrial salamanders spend their lives in underground retreats, moving deeper during drier months and below frostline in winter. In spring, chockfull of hormones, water-breeding species await cues to begin a pilgrimage to ancestral ponds; when the ground thaws and a rainy night provides for optimal travel, it’s goin’ home time.  

I feel privileged to witness these nocturnal scrambles. Not simply because they are deeply fascinating or that so few people ever see such things, but because so few will ever have a chance to: disease, shrinking habitat and road mortality have made such spectacles increasingly rare. Habitat destruction tops the list in Canada, and includes the effects of clear-cutting, stream-channeling, pond-filling, wetland drainage, agriculture and pollutants. Because their semi-permeable skins and typically biphasic life cycles make amphibians indicators of local environmental health and climatic trends, their current worldwide decline bodes poorly for a global environment on which we also depend. 

Because amphibians are adapted to specific regimens for breeding, larval development, and adulthood, climatic flux acting at any juncture can affect both populations and overall distribution. Global warming, for instance, will favour a few species but be detrimental to most. In southern Ontario, increasingly frequent mid-winter mild spells have prompted premature breeding by some species, whose eggs are then destroyed by freezing when weather returns to seasonal norms. At the other extreme, exceptionally hot spring days cause water temperatures to skyrocket, accelerating fungal, algal and bacterial growth with accompanying rapid depletion of dissolved oxygen that can kill eggs or cause developmental abnormalities, effects that are exacerbated when shade vegetation that moderates water temperature is cut from the margins of aquatic habitats.  

While human activities and fragmented habitat drive local amphibian extinctions, what happens during natural climatic shifts? Basically, the same thing—changing distributions of species adapted to particular ecological/climatic associations. The difference is that these occur gradually over vast periods of time as part of larger, integrated change.  

The hockey games and bars are long since done when I finally turn off my light at the beaver pond. Billions of raindrops fall in any instant, but in the dark, where sounds are always clearer, I differentiate between the tattoo drummed over the forest floor and the atmospheric noose closing around the pond, where hundreds of frogs cluck and whistle. My final thought is that even superficial understanding of such little-known netherworlds grants awkward membership: if I were a frog or salamander, I’d know just where to go and what to do. —ML

 

 

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