The Big Night, or Sex in the Wild

Or how I spend my days...

Amplexus is the word for wood frog mating. The male is on the top, female on bottom. Photo taken in out backyard a couple of days ago.

Big Night in Vermont is the moment, usually a rainy night in April, when the wood frogs and salamanders, sufficiently awakened from the winter dormancy, all decide at once to migrate from the woods to a nearby vernal pool to breed. It really does happen all at once; an epic hike, a stampede—many die on the roads trying to get home; this year it was roughly April 10 to April 12. It happens no matter how foul the weather is or if there is still ice in the pools. These animals are on a clock: they have to breed and lay their eggs early enough so that the eggs have time to produce young before the pools dry up in the mid to late summer.

This is a wonderful process of interlocking ecological habits and habitats. The frogs and salamanders breed in vernal pools because vernal pools, by definition, are pools of water that dry up in the summer (or at least every year or so), which means there won’t be any fish, fish being predators partial to frog eggs. And they have to be quick to give their progeny a chance to survive the disappearance of water, so they are triggered to get out and mate at the first onset of warmish weather.

A vernal pool in the wild

I am up on this because I am ADHD (and I make no apologies for my sundry obsessions) and must have something to study besides the thing I am meant to be studying and writing about. And as luck would have it, we have a disused swimming pool in the backyard, which I have turned into a habitat for these animals. It’s not exactly a vernal pool; it never dries up; but it is vernal pool-like and doesn’t have any fish. It’s surrounded by an aging wooden fence where black raspberries and wild grapes create a tangle of vegetation. Song sparrows and phoebes like the fence. I have already spotted the phoebes perching there, then diving out over the pond for insects. Though right now nothing is green yet. It all seems dead until you look at the water.

I heard the wood frogs first this year on April 11 walking next to a genuine vernal pool in a nearby woods with the dogs. That night, at midnight, I heard them in the backyard, and the next day you could see the males disporting on the surface (the males mostly disport on the surface with the females hiding out under the water). They look like little dark triangles just breaking the surface, with bulgy eyes at the apex. And they quack like a convention of ducks. When I go out there, they do this ostentatious group panic thing and dive for cover with a plop and splash, leaving expanding circular ripples. If I stand at the side of the pool, brave individuals will then break the surface and warily stare at me, then pretend to panic again and dive for cover (I am sure they are pretending; one just knows these things).

My private vernal pool with all the male wood frogs disporting on the surface (those little stubby triangle shapes).

Sex happens from the start; egg rafts appeared two days after the Big Night anchored against the side of the pool (rafts are made up of any number of softball-sized egg masses; the females seem to like to bundle their eggs together). Frog sex is called amplexus; the male is on the female’s back clutching her tightly, desperately perhaps; the females are larger than the males and a different color; the first time you see this, you think they are different species and that, wait, this shouldn’t be happening. But, then, what you learn from watching your swimming pool-turned-into-a-vernal-pool is that nature is extremely odd not to mention Nietzschean when it comes to reproductive competition and predatory violence; we have resident garter snakes that eat the frogs, frogs that eat frogs, newts that eat frog eggs, and any number of incredibly vicious looking bugs that dash around under the water like hunter-killer drones.

I have an eye on nine real vernal pools out in the woods; they are fascinating, isolated, and beautiful places; but my backyard pool is best for observing things because it’s not surrounded by mud and blowdown. We can sit right at the lip of the pool and peer at these animals only inches away through water that is clear and free of algae and duck weed (already, two of the pools in the woods are growing duck weed veils). I have built up a nice vernal pool bottom—leaves, grass clippings, sunken logs, tree branches, piles of loose rock—at least, I think it’s nice, and, really, the animals seem to be having the time of their lives spooking around down there.

One of the yellow-spotted salamanders in our pool, photo a bit foggy because she is under water. Please, a little applause, for the habitat I’ve created.

One of the delights this year is the presence of yellow-spotted salamanders. I did actually see one of these swimming in the pool two years ago (seemed huge, positively prehistoric, and beautiful), but this year we seem to have a colony—three separate groups of egg masses and a number of individuals (okay, maybe we are just seeing the same one over and over; who knows?) I should explain that it’s only this year that I have managed to differentiate the various kinds of egg masses. Salamanders have a very complicated sex life, which I haven’t totally managed to understand yet. The males apparently deposit sperm in little white piles on dead leaves or twigs in the pool. These piles of sperm are called spermatophores. And somehow by doing a little dance (I kid you not) the males attract a female to their spermatophores.

One end of a much longer raft of wood frog eggs.

Yellow salamander egg masses. Note the gel sack that contains the eggs. The white colored ones are a normal variation. The gel sack differentiates the salamander eggs from the wood frog eggs, which are just bundles of eggs with no outer sack. There are far more eggs in a wood frog egg mass than in a salamander egg mass. And the lady wood frogs like to lay their egg masses together in so-called rafts whereas the salamander egg masses are mostly separate. (Again, photos taken in our backyard pool.)

All this probably sounds a bit nutty; at best it’s difficult to explain what a wonder it is to see these creatures undulating up out of the mass of brown leaves and twigs, the strange clay-black-purple of their skin, those arresting yellow dots, the oddly rounded snout and big eyes. And this year we’ve managed to photograph them and make videos (they are so elusive that I can’t imagine how I would do this in the woods). These salamanders are land creatures, with lungs, so they have to surface now and then to breathe. Sometimes, if you know where they are, you can wait for them to surface. And this is your best chance to see them; they are a species of what are called mole salamanders because they live mostly underground.

But then this means you spend a lot of (writing) time sitting or lying by the pool watching the water and gradually you see more and more living things down there (it helps to have a partner who is actually better at spotting unusual life forms). Unidentifiable things. (Well, I am a neophyte.) Surprisingly, we already have huge numbers of big-headed tadpoles that mostly lie on things near the bottom like dull brown long-tailed kites, occasionally moved to move, fanning their tails lazily or wriggling frantically (as they do when they scoot up to the surface now and then). They have pearly white bellies that flash when they turn. There are so many that when they get excited and decide to run away, it’s as if the entire dead leaf floor of the pool comes alive with their wriggling bodies. My reading tells me these are green frog tadpoles who over-wintered in my cleverly-amassed fake vernal pool floor. There are also slender eastern newts, much smaller than the salamanders, with tiny delicate feet and yellow underbellies (the tadpoles and newts have tops that blend in with the leaf detritus making them hard to see). I watched two newts circling around one of my spotted salamander egg masses earlier today—the newts prey on other people’s eggs.

There is much more. I saw a water stick insect earlier today. Also masses of mosquito larvae and a very heavy looking mosquito resting on twig by the poolside. And any number of strange bugs, maybe a caddisfly nymph, and indeterminate others. Spring peepers will come later and then green frogs. Last year a painted turtle deigned to visit for a couple of weeks, spending sunny days resting prettily on a log (which I had placed carefully for just such an eventuality). And the snakes (I will spare you the snake-eating-frog video). A neighbor keeps several bee hives and his bees come to our pool for water (you can watch them huddling at the edge then zooming up and over the house back to their hives).

I can write about this now because, though I really don’t know much, I have achieved a magical convergence—my pool has developed into a habitat while my reading has scaled up to the point where I can now make good connections between what I see in the woods, what I read, and what is happening just beyond out back door. It’s actually quite thrilling in a quiet, self-satisfying way, oddly personal, even private. Sigh.