I have heard Chorus Frogs every spring for my entire life, but I never saw one until May of 2008. I was following Mike Forsberg around southeastern Montana in search of stories and photographs for Mike’s book, Great Plains: America’s Lingering Wild. I can’t remember what our objective was, but we were in the middle of an enormous pasture and we were walking. It takes a long time to walk anywhere with Forsberg because he stops and looks at everything. When you walk with any good photographer what you are really doing is wandering.
So I was wandering around southeastern Montana with Mike Forsberg on a beautiful spring afternoon taking pictures of flowers, clouds, rusty barbed wire fences, and windmills when the faint sound of Chorus Frogs drifted over a hill. The vocalization of a Chorus Frog is a little like a variety of small frogs known collectively as “tree frogs and their allies.” The Chorus Frog must be an “ally” because they are often found where there are no trees for miles. That was the case that day in Montana – no trees, just grass, and a little wind. The sound of the frogs blended in with the rustle of the wind and the songs of prairie, ground nesting birds that were newly back from their winter migration. Male Meadow Larks, Bobolinks, and Buntings were setting up territories and serenading the females with all their hearts. Probably the singing of the Chorus Frog had been blending with the ambient sounds for a while before we even noticed it, but as the afternoon wore on, the sound intensified until Mike couldn’t stand it. “Have you ever seen one of those little devils?”
I shrugged. “No. I’ve never even looked for one.” In fact, Chorus Frogs are such a common feature of the Great Plains that I had never even thought much about them. Since I could remember, they were a constant in the soundtrack of my spring existence.
When we walked over the hill and found a small stock-pond created by a dike built across a little draw. Spring runoff had filled the pond and the Chorus Frogs were doing the amphibious version of what the birds were doing. Their shrill voices seemed to rise from the water’s edge of the entire pond. My Peterson Field Guide to Western Reptiles and Amphibians describes the sound of the Chorus Frog as prreep, prreep, but that description does not do it justice. It is an insistent sound when you concentrate on it but has the ability to recede in your consciousness until it is barely noticeable. The pond was alive with singers and we crept, shoulder to shoulder, up to the water where one particularly boisterous frog was sounding off. We moved like a pair of blue herons, very slowly, raising high and planting gently one foot at a time. When we got to the edge of the pond, the sound was gone, and I looked carefully, expecting the frog to leap into the water and disappear. There was no leap and splash, so we bent over and squinted along the grassy edge. Still nothing. He must have heard us and took off, so we split up and started off in search of the next frog. But we had only gone a few feet when the first frog started up again - exactly where we had been looking. We went back, but still saw nothing.
Other frogs were singing just a little way along the water’s edge so we moved off again in opposite directions. I was intent on sneaking up on one before Mike did. I planned to find one and call Mike and his camera over to get the shot. We looked for the next hour - until the light stared to go out of the sky - but I never found one. Every time I thought I was close, the sound stopped. The frog seemed to slip away and I finally gave up. Mike had crept around his side of the pond and was now nearly where I sat on the bank, getting ready for the sunset. The intensity of the pond’s chorus had grown and Mike had given up trying to approach one. He was now on his hands and knees looking like a moussing house cat. I was ready to ignore him and turn my attention to the western sky when I saw him reach, with extreme stealth, for the Nikon that hung from his neck.
'Holy moly,’ I thought. ‘He sees one.’
I moved quickly to within five feet of him, then gently to a position just behind him. By then his camera was clicking away like a metronome. I looked hard but didn’t see what he was taking pictures of. I leaned closer but didn’t see anything until I was practically breathing into his ear. I was sixteen inches from where the camera was pointed and still didn’t see anything. But from right where I was looking a crisp prreep, prreep rose into the prairie evening. The camera clicked off again and again - but I didn’t see a thing. Finally I got real close and sighted over Mike’s ear and right along the camera lens.
Holy moly - there he was. By the noise he was making, I was expecting something the size of a hamster. This guy could have sat comfortably on a lily pad the size of a dime. He was the exact color of the pond water and he sat perfectly still.
Mike got a great picture of him, half submerged with his air sac expanded like the bellows on the world’s tiniest set of bagpipes (see page 161 in Great Plains). We sat on the pond bank and watched the sunset and he told me that Chorus Frogs have the ability to go dormant during dry spells. “When the weather is dry they burrow into the ground and wait for rain.” I listened to what Mike had to say but the adaptation to this fickle land that Mike described bounced off my brain. The incredibleness of it didn’t soak in until last week.
We have been in terrible drought for the last eighteen months. It didn’t rain once last summer and we had almost no snow during the winter. The pasture where the buffalo usually have their calves was dry and the stock-pond that they water out of has not had a drop of water in it for over a year. At the end of March, we trenched a waterline into the pasture from an adjoining one and set up a fifteen hundred gallon tank for them to drink out of. By the time we moved them in early April, there was enough water to keep them happy but there was not much old grass from last year and very little beginning to grow. The hope was that the predicted spring snow would get the grass growing and maybe even put a little water in the dam. But when the snow finally came in the second week of April and began to melt after a week of whiteness, the moisture went right into the dry ground.
I drove out through the buffalo on the twenty-fifth of April to check for calves and found five new babies following their mothers through the soggy pastures on their way to the new tank that we had put in. It was good to see the first babies and it was nice to see a little moisture soaking up the grass roots. But when I made a swing out to the pond that was the traditional watering hole for that pasture I found the same rock-hard pond bottom that had been staring at me for a year and a half. There were still a few snow drifts that hadn’t quite melted, but nothing had run into the dam, and I was glad that we piped water into the pasture.
Two days of sunshine later, the grass was turning green and the day was clear with enough clouds in the west to make for a great sunset. Jill had wanted to get some pictures of the calves and it would be hard to get a better evening. It was so nice, in fact, that we called up Jilian and Colton and asked if they wanted to ride along in the ATV.
We took the super quiet ATV with four seats and pulled through the gate just as the sun touched the first of several layers of clouds. A mile and a half to the west we saw a few buffalo silhouetted on the high ground that divides the pasture. We figured that the whole herd must be over the hill in the direction of the dried-up dam. As soon as we topped the hill, the herd was suddenly splashed out in front of us like three hundred bowling balls on a golf course. The sun was low and we saw tiny golden fluff balls sticking close to their mothers. Occasionally, one of the fluff balls would take off running at top speed and circle its mother in a show of sheer joy.
We approached slowly and the mothers without calves began to amble in our direction. Their curiosity had gotten the best of them, but the mothers with calves were cautious and held back until we stopped the ATV and sat perfectly still. A natural, prairie silence settled on us - enough breeze to rattle the dry, old grass, the eternal tender grunts of the buffalo, and behind it all, what sounded like Chorus Frogs.
‘Can’t be.’ I thought.
Now there were twenty or thirty babies. They are hard to count because they stick so close to their mothers. Jill was snapping pictures by the score. We tried not to talk and spoil the effect of being just another group of mammals there, witness to that domestic scene that persisted, day and night, year after year on this prairie for a millennium. Jilian was trying to capture some of the scene on her cell phone camera and she was the first to ask about the sound that underlay it all.
“What’s that noise?”
I shrugged. “I don’t know, sounds like frogs.”
“Frogs? Sounds like the world’s largest bee hive.”
“Tree frogs?” Colton asked.
“Spring peepers,” Jill said.
“No," I said. “Chorus Frogs.”
We idled the ATV to where we could see the pond that had been bone-dry two days before. But it was not dry that evening. Somehow the land had soaked up ninety percent of the snow, but the last trace of the drifts must have run into the dam. Now it was half full. Two hundred yards of water - fifty yards wide - and the pulsing din of the Chorus Frog song nearly overwhelmed us. It was difficult to imagine how they had survived and how they responded so quickly to a minor surge of moisture.
“There must be thousands,” Jill said.
Jilian was already out of the ATV and walking toward the pond. We quietly followed her to the edge of the water and stood bathed in the last rays of the sun and the sound that had been absent from this prairie for over a year.
“Let’s go catch some,” Jilian said. Remembering the hours that Mike and I had spent trying to simply see one, made me smile. “No,” I said. “Let’s just stand here and listen.”