Last night the spring temperatures moderated here in Illinois. The air was calm and the collective voice of chorus frogs singing in the wetland behind our house could be heard inside even with the windows closed. So we grabbed our flashlights and waded into the wetland to see if we could find a frog and get a photo.
It shouldn’t be hard, but it is. In case you’re not familiar with the call of chorus frogs, when singing together they sound like a single high pitched note. Heard closer, each frog makes a noise like the sound of a finger clicking across the tines of a plastic comb. It has a creaking quality, and even a single frog is quite loud to the ears. It is equivalent to turning the sound up about halfway on your car stereo. These little frogs are loud.
But they’re not large. Chorus frogs are not much bigger than the length of your thumbnail. Yet their ability to fill their throat sacks with air and pump out noise is quite well developed. Amphibians have a long and colorful history in the evolution of the world. This wonderful description from ThoughtCo.com gives just a snippet of why amphibians are so significant to understanding our own position in this scenario:
Here’s the strange thing about amphibian evolution: You wouldn’t know it from the small (and rapidly dwindling) population of frogs, toads and salamanders alive today, but for tens of millions of years spanning the late Carboniferous and early Permian periods amphibians were the dominant land animals on earth. Some of these ancient creatures achieved crocodile-like sizes (up to 15 feet long, which may not seem so big today but was positively huge 300 million years ago) and terrorized smaller animals as the “apex predators” of their swampy ecosystems.
Pecking orders
Now, chorus frogs aren’t about to chomp on your foot and suck you down into the watery abyss. But there is a pecking order in this world among all animals. And even chorus frogs have to eat. A site called BioKids.com shares: “Chorus frogs eat a variety of small invertebrates, including ants, flies, beetles, moths, caterpillars, leafhoppers, and spiders. Newly formed froglets feed on smaller prey, including mites, midges, and springtails. Tadpoles are herbivorous, foraging mostly on algae in the water.”
While singing, the last thing on any chorus frog’s mind is eating. They are basically a pack of horny males trying to get a chance to mate. The louder the call, one must suppose, the more inviting to the female. Such is the order of nature down to some of its smallest occupants.
Humans afoot
So we walked out into the wetland behind our house with our flashlights hoping to find one boldly calling male whose ardor put him in view. Alas, we had no luck. Chorus frogs excel in camouflage (see their cryptic coloring?) despite their loud calls. You can be standing right above them listening to their calls and still it is hard as heck to see them.
I’ve actually had more luck during daylight than at night. A few years back during a Naturalist Certificate class, we paid an April visit to a preserve where chorus frogs were singing in the middle of the morning. They often sing all day and most of the night. And for some reason one of these little guys was perched right on top of a knob of wood singing his little guts out. The tiny throat sack below his froggy chin pulsed with each call. It was fascinating to see and hear.
Earning froggy credits
Way back in college, I enrolled in a field biology class where part of our spring project was to capture no less than six species of frogs. We’d release them after chronicling their ID in the classroom. But there was a very short window of time in which it was possible to even find all six frog species. There were spring peepers and cricket frogs. Leopard and green frogs. Bullfrogs and chorus frogs. And if one was really, really lucky, one might find a wood frog calling. But that was extra credit.
At one point, my frog hunt involved wading out into a cold spring where the water was just above forty degrees. I was skinny as a rail back then and possessed of my own set of scrawny frog legs from all the running we were doing in spring track and field. We didn’t have wading boots so the task of entering the water was chilling to say the least. But I was struggling in field biology because the lab work was vexing to my art major brain. So I needed every ounce of credit I could gain. So the frog hunt was on.
Standing out in that cold spring was enlightening. After a bit, the cold wore off and it was just the dank pressure of water on my thighs. Feeling my way across the bottom with my feet, I proceeded slowly toward the sound of some frogs singing in the center of the pond. It wasn’t deep, but it was dark water and smelled vaguely of the history of the entire earth.
We are all formed from water. Descended from amphibians. Borne of the ages. And that afternoon after the frog hunt in the cold spring, I felt cold-blooded during the mile run in which I competed. I couldn’t warm up well no matter how much I tried. Lesson learned: warm-blooded creatures need fat to keep themselves warm. I had none at the time to apply to that purpose.
It took a while in that cold spring to catch a chorus frog. But eventually, I snagged a pale specimen and plopped him into the jar with the holes poked in the lid. I also captured a spring peeper that day. But getting one frog into the jar without allowing the other to hop out was quite a trick while standing hip-deep in water so cold I did not know if my testicles would ever return to normal size again.
Frog assembly
Back at the dorm I already had a small aquarium filled with the other frogs required for the assignment. I assembled partitions to keep them apart. But somehow the leopard frog that I captured earlier that day wriggled its way around its wooden partition and snapped up my chorus frog in its mouth. I quickly jammed a hand in there and picked them both up. The pale legs of the chorus frog were still protruding from the mouth of the leopard frog. So I gave the sides of his mouth a squeeze because I knew the bone structure from having dissected a few leopard frogs over the years. That made the frog release my other specimen and I made better preparations to keep them apart.
Forty years on
So it was with a bit of nostalgia that I crept around the wetland last night in hopes of seeing one of these little buggers singing. I’m grateful to live so close to a wetland like this. I could turn and look at our house where the lights were on and I knew it was warm inside.
Eventually, my toes really started to feel numb. My daughter and her beau were also out looking, and one hopping frog was spotted. But no photos were captured. So we headed back inside and I took off my old running shoes and my soaked jeans in the garage, then threw the lot into the laundry.
Round two
I have not given up this year’s frog quest. There is still the opportunity to head out there in the daytime. The frogs are singing and won’t stop for at least a week or two, maybe more.
After all, there is breeding to be done and millions of years of evolution to continue, and that’s a challenge these days. The world is not the vast domain of amphibians anymore. The odds against them have increased in many ways. Between water pollution and holes in the ozone, busy roads and drained wetlands, amphibians are struggling to keep their toehold in this world.
Fate alone can be harsh. Last year our little wetland released a large hatch of green frogs that emigrated in all directions. Their smashed bodies were seen all over the road and frog legs were everywhere. An enterprising flock of gulls could have eaten like kings.
But mostly, such events amount to squander. That is the way of nature. It works hard to evolve something unique and useful such as frog legs and more often than not, tosses all that effort away to extinction. 99% of all the living things that ever existed are now extinct.
Some might argue that’s a good excuse to ignore the effects of human activity in this world. The extinction rate among plants and animals in this world is rising as the human population increases. The competition for food and space and resources is all-consuming. But it is possible that we can consume ourselves to death.
To feel the chill realization of your own frail humanity, I suggest wading into a cold spring wetland. And stand there a while. Listen to the call of frogs echoing to you through millions of years. And realize that all you’re really doing is standing on your own set of frog legs.
I did hear some good environmental news this morning. CO2 emissions in the US have been decreasing by about 1% over the past few years. In 2017 it was less than 1%, but it still declined.
They attributed the decline to the switch from coal to natural gas and wind and solar.
That’s some bit of progress eh?