Frog Watch and the Amphibian Curriculum
Posted: July 1, 2010
by Geoffrey Selling, Germantown Friends School
Early April:
I find myself wondering if this Frog Watch project is a bust. Here I am, with three second grade families in tow, slipping in the muddy grass as we descend in the dark to Spring House Pond at the Schuylkill Center for Environmental Education in Roxborough. This is our third pond and the first two have yielded no frog songs. It’s approaching 9:00PM and everyone is tired and a bit disappointed at the silence at our first stops. We are to listen for frog mating calls for a three minute interval at each of three ponds, and then look for signs of amphibians. All data is to be duly recorded on the Frog Watch sheets, which will later be tallied and faxed to the US Geological Survey which conducts Frog Watch nationally. But what if there are no frogs or toads? How utterly disappointed the second graders will be, even if I explain to them that scientists don’t always get the results they want right away. After all, each threesome of families that signed up for these Tuesday night amphibian hunts gets only one chance. It will hardly satisfy a seven year old to tell her that it’s just too cold tonight for frogs to be calling. I can already hear, “It’s not fair!”
And cold it is! Though it’s early April, there are tiny patches of recent snow still clinging under trees, and bits of ice here and there. Cold-blooded amphibians can’t do much in cold weather. That’s why they are more active in warm weather. But when I put up the Frog Watch sign-up list on my science room door, none of us could predict which nights would be warm and balmy and which would be too cold. So here I am, expecting a third disappointment and wondering how these eager children will handle it.
We seat ourselves on the steps above Spring House Pond and I set my watch for the three minute listening interval. Since frogs and toads are not usually scared by light, I tell the children they may shine their lights in the water while they listen. Suddenly, one little girl gasps, “There’s a tadpole----he’s huge!” And sure enough, as we all train our flashlights where hers is pointing, we see a large grayish tadpole, some two inches long, swimming along the bottom. Then someone else spots another and another and another. The night is suddenly alive with delighted squeals of children as they find a veritable “crowd” of tadpoles. I explain to the children that these are not this spring’s tadpoles, but babies that didn’t complete their metamorphosis last summer. They buried themselves in the pond’s bottom over the winter and will finish their maturing into adult frogs this summer. When the three minute timer beeps, the children dash down and scan the large pond with their lights, finding more and more tadpoles. I can hardly get them to record on their sheets what they’ve seen and how many. They want to write down that they’ve seen “millions” and I have to explain to them that a scientist must count and report exactly what was seen, not some wishful guess. They furiously count and record, though I suspect a number of tadpoles got counted two or three times. The children are ecstatic and one little girl announces that this is the most fun she’s ever had. As I drag them away from the pond, we poke our noses into the old spring house and see a water snake in the corner and a glaring phoebe, watching us suspiciously from her nest. What started out as a cold gloomy spring night has turned into a thrill for all of us. We traipse up the hill, through the mud to turn in our record keeping sheets. Frog Watch looks like it might work!
The US Geological Survey (USGS) is conducting Frog Watch in response to concerns about the health and number of amphibian populations and species diversity nationwide. In order to gather sufficient data, thousands of data collecting scientists would be needed, for which there is no funding. The USGS did what many such studies have done: turn to “citizen scientists”. By training and using an army of volunteers all over the country, a vast body of data can be collected that will reveal a more comprehensive picture of frog and toad populations than the available scientists could collect. For each targeted site (and there are thousands), the volunteers are trained in the protocols of data collection and taught to identify the frog songs for that area. Some areas support more than a dozen species and some much less. One of the things that appealed to me about the Schuylkill Center’s program was that only three species have been identified there in recent years: green frogs, pickerel frogs and American toads. This seemed like a manageable number of calls for second graders to learn and remember. Moreover, the protocols, which included collecting simple weather data and three minute listening intervals seemed within the skill and patience level of second graders.
Frog Watch relies on frog songs more than observations for several reasons. At night, it is often hard to see and identify frogs and toads. They are amazingly camouflaged, and unlike their tropical cousins who stand out brilliantly in the rain forest (a sign that they are poisonous), North American amphibians blend in. Moreover, in large ponds, it is virtually impossible to see amphibians at a distance. But frog and toad calls are very distinctive. They call as a way of attracting mates, to establish territory and to signal alarm. Each species has a unique call, and few if any sound like the proverbial “croak” or “ribbit” that we’ve come to associate with frogs. Listening to the provided CD of calls revealed a cacophony of chirps, snorts, snores, clicks, trills, and the children’s favorite: fart sounds (the Eastern spadefoot toad). Not only do frogs call and call often, their spring calls are usually a sign of mating and this speaks to the propagation of populations. Additionally, calls can be heard in the dark and over great distances.
My evening training session at the Schuylkill Center was fascinating. I learned more about the three local types than I’d ever expected, memorized their calls and came home armed with piles of reading matter and protocols with which to familiarize myself. I also had to figure out how to present and manage the project with seven and eight year olds--no mean feat. But the second grade at GFS studies amphibians in the current science program, so it made sense for them to do Frog Watch. Most of my fellow trainees, except for a wiggly group of 10 year old Cub Scouts, were older people and Schuylkill Center regulars. They were familiar with Monarch Watch, Cornell Feeder Watch, Bluebird Watch--all important wildlife monitoring programs. As I drove home on that March night, I wondered if I hadn’t gotten in over my head.
Mid April:
Only a week has elapsed since the first Frog Watch outing, but the woods have changed. There is a greenish tinge to everything, even though most leaves are not yet visible. The evening is warm and breezy--perfect amphibian weather, according to all the books. Three little girls, plus two kindergarten siblings and assorted parents are all sitting on a small boardwalk adjacent to Cattail Pond. At our first stop, we heard one American toad call way off in the bushes. It sounded like a bird trill, and only one or two of the children actually realized it was a toad call. The Blue Route and Expressway are not so far off and the intrusive roar of trucks and cars can be heard. Suddenly, an American toad calls right behind us. Another answers across the pond. Then another echoes from the distant bushes. Then five or six in the pond begin to sing. More begin to call from the woods around. It is a veritable chorus of American toads. One of my second graders who is seriously hearing impaired, suddenly perks up and cries out, “American toads! I hear them! They’re all over!” All the collected parents and I exchange glances. This is truly a special moment. There are so many toads we can’t count them all, and on our charts, that is considered a Class Three Chorus. The children are delighted to record this. Later in the evening when we find a dead pickerel frog and see a green frog, they are pleased, but not half as thrilled as when they’d heard the deafening chorus of toads.
Late in April:
Another eager group of children is tromping down the hill through the now verdant meadow. Leaves are appearing everywhere and this group, having been prepped by last week’s group, is determined to hear an even louder chorus. There is something in children that makes many of them want to be able to report the biggest, the most remarkable, the most exciting of anything. According to my Frog Watch song chart, each species has a particular seasonal niche when its calls are the most frequent. This is the time for the American toads. As we approach Polliwog Pond, a dark lump on the ground suddenly moves. It’s a toad. The children all want to pick it up and take it home. I have to remind them again and again why we are here and that collecting is not allowed or even good for the toads. As we walk, we hear one or two distant birdlike toad trills but no chorus is forthcoming. But as we move from Polliwog to Cattail Pond, the children discover that the path is covered with toads. They are virtually everywhere, trying to vanish into the ground with their stillness. We see dozens. Remarkably, they are far from the pond. Then one sharp-eyed child notices an extra large lump. As we train our flashlights on the scene, we see a male toad mounted on a female in the characteristic mating grip, known as amplexus. When the female releases her eggs, the male will fertilize them externally as the eggs emerge into the water. But this pair is a good 100 feet from the pond. The female knows better than to release her eggs onto the ground and the male doesn’t seem to care. Then, right in front of our eyes, the female hops off into the bushes, with her suitor still clinging to her back. Now that takes strength! The children have a dozen questions and I find myself giving the basic sex education lesson in a very real setting.
Why does the USGS and the scientific community care so much about amphibians? First, there was anecdotal evidence that frog and toad populations were declining. Others noticed that certain species seemed to have vanished from certain sites (extirpated or locally extinct). A startling number of amphibians have been born with serious defects, such as misplaced, or structurally incorrect or missing legs. It turns out that amphibians are particularly sensitive to environmental stresses, such as pollution, temperature changes and even changes in ultraviolet radiation. (My wife, Cecily, and I encountered some strange UV ray measuring devices in the high alpine lakes of the Olympic National Park in Washington state, which were part of an amphibian/UV light study.) Unlike many vertebrates whose skin is mostly impermeable, amphibians actually take in oxygen through their skins, even as adults. This permeability probably means that various pollutants and disturbances in their habitats are felt more immediately and dramatically by amphibian populations. But scientists are not content with anecdotal data. They need hard numbers to document the declining populations and extirpation of species.
Why do we care so much about amphibians in the Lower School? They are a wonderfully diverse and fascinating family of animals that seem to hold a special appeal for children. From spring vacation until school’s end, the second graders learn about amphibians. Through the lens of amphibians, they learn about adaptations, life cycles, habitats, anatomy, diversity, food chains, natural history and so much more.
Late April:
Tonight, Frog Watch begins as every other Tuesday session. The children record air temperature, wind speed, recent weather events, and current precipitation. Tonight, for example, it is clear but by the time we reach our last pond, it is drizzling and so we need to change our charts, even as we try to keep them dry. If some of the children imagined that Frog Watch would just be dashing from pond to pond looking and listening, they quickly learn that there is a lot of disciplined work involved. Each pond has its own recording sheet and each sheet must include all the weather and frog data, correctly and legibly presented. Just managing the clipboards and flashlights is a challenge for some. “Why do we have to write so much,” one youngster complains as we complete the third sheet. Part of the power of Frog Watch is that it gives the children a taste of real science and all the nitty gritty behind the exciting moments. Science class is usually organized and planned around some very interesting activity that yields exciting results every time. But here at Frog Watch, there is no guarantee of success, and the children need to learn that even a night when nothing is heard is important, albeit disappointing.
Early May:
Tonight, as a new group descends through the now fully green meadow with a few golden rays of sunlight hovering in the air, an older sibling suddenly cries out, “There’s a bluebird!” and sure enough, there it is! Against the yellow green of young leaves, its blue is almost iridescent. Its color is so striking that everyone easily spies it and an amazed hush falls over the group. We stand watching and marveling that anything could be that brilliantly blue. Then the bird flutters off into the woods. It turns out to be the high point of the evening. No frogs are heard at any pond and only two or three tadpoles are spotted at the last pond. But while we are sitting at the first two ponds in expectant silence, we hear the absolutely clear and bell-like call of a wood thrush, singing its evening song. The children and parents are startled and amazed. “It’s so beautiful!” a squirmy little boy gushes. On this night, when amphibians are scarce, the serendipitous birds are our reward and though we are all sorry not to have heard frogs, the children feel very special at what they have seen and heard.
More than half of the GFS second graders signed up for Tuesday Frog Watch outings. But I prepared the whole second grade. As I listened to the CD of Pennsylvania frog calls that the Schuylkill Center furnished me, I was delighted and amused by the variety of sounds. Why not learn all of them? And thus began the frog song project. Each science class began with me cradling the CD player in my arms and playing a number of frog calls. On the blackboard was a poster of all the Pennsylvania frogs and toads. We added one new call each day and reviewed earlier calls each time. The children found some of the calls hysterically funny or surprising and we kept a list of what the calls sounded like to them (someone rubbing a wet balloon, a carpenter hammering nails etc.). As the weeks passed by, I was amazed how most of the second graders could reliably identify 10 or more of the 14 Pennsylvania frogs. Several parents reported taking families for springtime walks in parks and woods, with the children confidently calling out, “Spring peeper in the grass!.......there’s a wood frog over there!”
Late May:
In talking with Kathy Bright, Education Director at the Schuylkill Center, I have learned that the green frogs, which were so abundant last year (2002) are barely in evidence this year (2003). Have they disappeared? I wonder aloud with tonight’s crew. In all our Frog Watch expeditions, we haven’t heard a single green frog and only saw one. As we head down the hill, the children speculate what might have happened to them. Green frogs have an appealing call....a deep, rubber band like “gump” sound that is unique. When we sit down at Polliwog Pond, before we even start the timer, we hear our first “gump.” An answering call comes from across the pond. By the time our three minutes are up, the children have counted six or seven different individuals. I stress that each child can only record what he actually heard, not what the others have heard. When we go down to the pond to investigate, we see green frogs along the banks. As we approach, they splash into the pond and vanish in the mud. With our flashlights ablaze, we find them all over: some mating, some resting in the grass, some burrowed in the mud. “So they haven’t disappeared after all!” says one tiny girl, with relief in her voice. I can hardly tear this group away from the first pond because they are having so much fun spotting green frogs.
Throughout two and a half months while Frog Watch continues, the children’s every science period is focused on frogs, toads and salamanders. Each child has a small tank that started with five grass frog eggs. Without predators to eat them and under the protected conditions of the classroom, a startling number hatched. I had ordered 400 frog eggs, but NASCO sent about 800. Of these, startlingly few died and so every child had a full tank of tadpoles. Each week, the children draw their tadpoles’ progress, write journal entries about their growth and view a few particularly large samples under the video microscope. We read books about frogs and toads, learn about their differences, their adaptations, their tropical cousins, watch amphibian videos and even play frog games. When I excuse each table after clean up, the children go hopping out of the science room. We also kept classroom tanks for tadpoles for the children to watch so that they could monitor the tadpoles’ growth in between science periods. When I did this unit two years ago, we started with small tadpoles and by the end of school they had completely changed into tiny froglets. But this year, starting with eggs put us about two weeks behind. The result was that by the last week of school, most of our tadpoles had hind legs, and many had front legs, but none were fully formed frogs. It was a tradeoff but I think I prefer the latter method, where the children got to see their eggs hatch.
Mid May:
With our evening observations now complete, we climb the steep hill to the Schuylkill Center to turn in our results. Each Frog Watch outing ends this way. Suddenly, everyone is tired and ready for bed (especially the adults!). The Center is dark except for outside lights; the evening events are over. We open the Frog Watch box in which our results go and each child contributes one paper (one from each pond) so that we don’t report results twice. In the box is a notebook with all previous observation sheets chronologically filed. We always take the book out and see what other people have observed. It especially delights the children when they see their friends’ sheets from previous weeks. Somehow, the notebook make it all more official looking and reminds these youngsters that their own results will soon be entered in the book and part of the Frog Watch data base. Though it was usually 9:15-9:30 when we got to the box, it never failed to interest the children.
In the days following each Frog Watch outing, the three children who attended reported to their classes what they saw. Being young and literal, they want to recount every detail. With some coaching, I helped them to identify the unique and special moments from their night out. They were immensely proud of sitting on the teacher’s stool and telling their classmates their important observations. The classes listened and asked questions. It was as if the sharing validated the whole process. They actually had some real science to share. “But you said the green frogs hadn’t been heard this year,” one non-Frog Watcher protested almost accusingly, when a boy in his class reported the crowd of “gumps” we’d heard the night before. ‘Well, I guess they just hadn’t come out yet,” said the reporter, “because we saw and heard an awful lot.” The class is impressed. The importance of the sharing sessions was brought home to me when a little girl was absent on the day that she was to report. One of her classmates recounted the whole tale. Three weeks later, this shy girl came up to me after class and whispered, “I never got to share about Frog Watch.” “Would you still like to?” I asked. She nodded emphatically and the next period, in a barely audible voice told about the tadpoles she’d seen.
Early June:
Tonight, we haven’t heard much or seen many frogs......just a few tadpoles in two ponds. Yet, as with every previous Frog Watch visit, the three minute intervals of silence and listening have been magical. Whether we’ve heard frogs or toads or nothing, we’ve stopped long enough from our busy lives to listen to nature: to hear the birds chirping, to feel the soft breezes brushing our faces, to smell the wet earth and fresh spring leaves, to experience the stillness and calm of the forest. These are magical moments for the children and adults alike. Stopping oneself long enough to open oneself to nature is a remarkably healing experience. No matter how stressful the day has been, these three pauses to listen and watch have made all of our lives a bit better. It’s true that Frog Watch occupied every one of my spring Tuesday evenings, but it’s also true that it was absolutely worth it.
This article is adapted from a previous publication in Studies in Education #86 Winter 2003-04.
Some Details about Frog Watch USA
Since this article was written, the organizational sponsorship of Frog Watch has shifted from the USGS to the National Wildlife Federation and now, more recently, to The Association of Zoos and Aquariums. The program still works the same way. Citizen scientists (including children) monitor amphibian populations in their own area and the data is then entered in a master database that includes all data gathered.
How to get involved: Contact area nature centers and science museums to see if any of them already are involved in Frog Watch. If not, contact: http://www.aza.org/frogwatch/
What kind of training is involved? A two hour training workshop for group leaders teaches volunteers about why amphibian populations are at risk, which frogs are likely to be heard in the target area, how to do the monitoring and how to record the data and send it in. I was trained at the Schuylkill Center for Environmental Education
The training included providing me with a CD of all frog and toad calls in Pennsylvania and I was given a list of amphibians that would be found at the Schuylkill Center site.
How often does one do Frog Watch? Some scout groups and clubs go once in a spring, but I take small groups of second graders every week on a designated evening. A group of three families is about the right size. Bigger groups get too noisy.
Why is Frog Watch particularly suitable for the early elementary grades? The protocols are quite easy. Young children easily learn and remember the different calls associated with their area. All they have to do is count the calls in three minute intervals and then circle various numbers on a chart. They also take simple weather signs (temperature, wind, precipitation etc.), which is easily done with a teacher’s support. Though Frog Watch USA is mostly interested in the calls themselves, there is a place on the recording sheet for observations. Local nature and conservation centers are usually interested in the visual data too.
The importance of Frog Watch: Frog Watch not only gathers important data which scientists cannot possibly gather without citizen help, it enlists youngsters in doing REAL science. This isn’t a cute game or classroom activity; this is real science!
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