Monday, May 9, 2016

A Three Toad Day

I joined my friend, Ranger Lesley McClintock, for a lucky day at Colorado National Monument. Lesley—alongside a seasonal ranger and a loyal band of volunteers—delivered and an environmental education field trip to second grade students (from an English-Spanish double immersion school), featuring hikes through the No Thoroughfare Canyon Trail, along the stream. Lesley showed her ability to interpret the science and wonder of insect life cycles and cryptobiotic soil, in both languages. In this living desert, there are the bright red flowers of claret cup cacti in bloom, and the green-and-yellow sheen of collared lizards basking in the sun. We passed a few clusters of toad eggs, and some tadpoles, along the route. A young boy pointed out to me a spider stretched horizontally on its web just over the water’s surface. After thinking it was first an insect, then an exoskeleton, I looked at it from very close up—yes, it was a spider. I congratulated the youngster on his sharp eye, then noticed more such spiders along the way.

When we arrived at the first pool, our destination, magic happened. Two Woodhouse’s toads drifted below the water’s surface, in their mating embrace. I posted myself next to them, as a sort of toad guardian. The kids were sufficiently preoccupied with the business of eating their lunches that they did not come to join me at first. Soon, a small band of boys and girls came closer, and exploded with excitement at the sight of the amphibians. The toads then swam to three feet farther away from us, where they met shade by the steep bank—presumably where they felt safer. I had to deter the excited youngsters as they attempted to poke the critters with sticks; they didn’t mean harm, but did seek a sense of agency from making the animals react. A trill noise happened at regular intervals. Following the noise, we spotted another Woodhouse’s toad perched on the rocky bank, his balloon-like vocal sac filling with each call. 

I explained to a boy, “He is singing because he is looking for a girlfriend.”

The boy asked, “Does the one in the pond already have a girlfriend?”

“Yes,” I answered.

Some of the girls were amazed to learn that the larger toad in the pair was the female. A girl asked me if the mother toad will come back to check on her eggs after she has laid them. I had to explain that in an amphibian’s world, every little egg and tadpole must fend for themselves, with no help from their parents. (I didn't go so far as to explain that eating one's sibling is common for the tadpoles of some species, including the next one we met.)

On our side of the shore, an awkward and pudgy elfin creature came shuffling along. I took a close look, and a huge and vaguely familiar pair of alien eyes stared back. It was as if the pictures I had seen in field guides and museum exhibits had suddenly sprung to life.

“It’s a spadefoot toad!” I declared, seeing this critter in real life for the first time. The amphibian was rather scared by the children who wanted to pick him up, held back by rangers. He tried to climb a crevice in the rocks, but fell, and tried to climb again.

Another spadefoot toad appeared and went swimming in the pond, and inquisitively approached the mating Woodhouse’s toads, as though unaware that he was of a different species. The spadefoot wasn’t too graceful in the water either, for their home is the earth. They are supremely adapted to the desert, spending up to a year at a time buried underground. When spring rains come, they emerge, gorge themselves on insects (a biologist observed a spadefoot eat 55% of his body weight in termites in a single night); partake in mating orgies wherein females can lay 3,000 eggs; and return to their earthen home. They can go from egg to adult toad in two weeks (or sometimes as little as nine days)--for in the desert, the water may not last. Inside the earth, they absorb water from surrounding soil. When the ground turns bone-dry, so can the toad. They can survive losing up to 60% of their body’s water and stay alive. Generally, amphibians can perform extraordinary physiological feats, as a result of their dependence on moisture, and adaptation to places where it can evaporate or freeze.

On the way back, we came upon a red-spotted toad in the stream.

Wildlife watchers at Yellowstone seek out a “three dog day,” which means observing at least one fox, coyote, and wolf on the same date. At Colorado National Monument, we had a three toad day. Considering the resourcefulness needed by amphibians of the desert, using the night time, the shadows, the puddles, the subterranean zone, sleep during drought and frenzy during rain—it’s a comparable spectacle.

I am not sure which species of Spadefoot toad we had. Lesley and I traded the camera back and forth, causing confusion over who took what picture, so we are claiming joint credit.

No comments:

Post a Comment