Earth & Sky

Celebrated Jumping Frog

JB: This is Earth and Sky with a story about a famous frog.

DB: “The Celebrated Jumping Frog of Calaveras County” is a short story by Mark Twain about a frog that can out-jump any other frog in the county. Some scientists think that the fictional frog was inspired by a real one – the California red-legged frog. When the story was published in the 1860s, there were estimated to be millions of native red-legged frogs in California.

JB: Back in Twain’s day, restaurant goer’s demand for frog legs led to its over harvesting. To make things worse, non-native bullfrogs were brought in and bred to satisfy the demand. Bullfrogs turned out to be aggressive predators of the red-legged frog.

DB: Red-legged frog populations have now dwindled to less than 1 percent of what they were in the 1860s. The last red-legged frog in Calaveras County was seen in 1979.

JB: In 1996 the Endangered Species Act gave legal protection not only to the frog, but also to the frog’s habitat. In order to thrive, it needs wetlands that combine still or slow-moving water with streamside vegetation like willows, cottonwoods, and cattails. Now, over four million acres in California have been designated as critical habitat for the frog.

DB: For more, come to today’s show at earthsky.org. Thanks today to the U.S. Forest Service and to the National Fish and Wildlife Foundation. We’re Block and Byrd for Earth and Sky.

The following individuals were interviewed for today’s show. Our thanks to:

Peter Galvin
Conservation Biologist
Center for Biological Diversity
Berkeley, CA

Dr. Robert Stack
Executive Director
Jumping Frog Research Institute
Angels Camp, CA

Interview with Peter Galvin:

ES: Thanks for speaking with me today. Can you please tell me a little about yourself?

PG: My name’s Peter Galvin, and I’m a biologist with the Center for Biological Diversity, an endangered species protection group.

ES: What are some of the things that the Center does?

PG: The Center for Biological Diversity was formed in 1989, and we have over 6000 members throughout the U.S. and North America. Our mission is to protect wild places and wildlife throughout North America. And to that end we work in research advocacy. Everything from researching the status of endangered species and trying to get them onto the Endangered Species List ? if they are not already ? to getting increased funding for the species protection and habitat acquisition and to, in some cases, filing lawsuits to try and get endangered species protections that they deserve.

ES: I understand that the Center has been doing some work with the California red-legged frog. Can you please tell me a little more about that?

PG: The Center has been involved with the California red-legged frog issues for several years. We have followed suit, along with a number of other research organizations, to get what’s called “critical habitat” established for the red-legged frog. And this means that the areas that the frog depends on for its survival and recovery, as a provision of the Endangered Species Act passed by Congress in 1973, that calls for the [U.S.] Fish and Wildlife Service to identify the areas that are central to the survival and recovery of a species and to designate those on a map, and then not fund federal activities or grant federal permits that would destroy that habitat. So we’ve been involved in a number of ways with the red-legged frog, but that is one of the most significant ways that we’ve been involved, is to try to get the critical habitat established for the frog, which it has been, and now, unfortunately a consortium of industry groups is trying to remove the habitat designation protection. We have intervened in an anti-environmental lawsuit that takes away protection for the red-legged frog. We’re arguing that the protection needs to stay.

ES: How would you describe what a red-legged frog looks like?

PG: California red-legged frogs are beautiful frogs. They’re the largest native amphibean in the West, and they range from about 1 to 5 inches in length. They have small black flecks and larger dark blotches, and they have a brown-gray, olvive, or actually a reddish background color. That’s where they get the “red-legged” frog name, from the reddish splotches that they have. Their range has been reduced by about 70%, so they’re down to about 30% of the areas that they used to occur in. There are two subspecies of red-legged frog on the Pacific coast. The California red-legged frog, rana aurora dratonia, is found basically from Point Reyes National Seashore in Marin County, southward into northern Baha California, in the Mexican state of Baja, although it may not exist in Baha anymore. It’s known to occur as far south as San Diego now.

ES: What is its habitat like?

PG: The red-legged frog occurs in aquatic, or wetland habitat that combine slow-moving water, backwater, with riperian vegetation, willows, cottonwoods, cattails. And they occur in this riperian corridor and at the edges of the riperian corridors ? riperian is just another word for stream side. And, basically, wetlands are a type of habitat that has faced enormous pressure since this country began. California has lost 90% of the wetlands that once occurred here. And so you can imagine that -not just the red-legged frog ? literally hundreds and even thousands of species that are associated with wetlands and aquatic areas have declined in California and the red-legged frog is one of the more notable examples. At one time there were literally tens of millions of these frogs. They were so abundant that they were considered a delicacy and eaten prolifically in restaurants in San Francisco. And in fact the red-legged frog was a very famous frog early on because it was memorialized in Mark Twain’s short story, “The Celebrated Jumping Frog of Calevaras County.” And the red-legged frog has been steeped in the folklore of western americana ever since then. So it’s a frog that people have paid attention to its decline. And it has a very broad, widespread support, I suppose partly from being Mark Twain’s frog.

ES: I understand that now there are no more jumping frogs in Calevaras County.

PG: No, they use non-native bullfrogs now. The frogs don’t stray too far from the riperian area itself. They go two or three hundered feet from the riperian area. Their whole lives are centered around the aquatic wetland habitats.

ES: How was the critical habitat determined?

PG: Critical habitat was literally defined as the area essential for the survival of the species. And so a variety of methods are used to determine what habitats are necessary for the frogs to survive. Firstly, the areas where the frog still exists. That is the cornerstone of any recovery srategy, to protect the areas where the frog still exists. Then, one has to look at the areas in between where the frog still exists. And that is to provide some connectivity for genetic interchange. Because one of the real crisises of wildlife is when wildlife gets to a very rare and imperiled status, like the red-legged frog, you might have populations of a species that aren’t able to interact with one another genetically, and that’s called inbreeding, and essentially that’s the death knell for any species or series of populations. So one of the things to look at are: where are the red-legged frogs today? And how to connect up the populations with corridors of habitat that will not be paved or otherwise be made unsuitable for the frogs to go back and forth. And the third phase is: what areas where the frog used to occur that no longer does, need to be rehabilitated in order for this species to ultimately recover such that it no longer needs the protections of the endangered species act, which is the goal of the Endangered Species Act, to provide habitat protection and recovery so that the species are, in essence, out of the “hospital.”

ES: Looking at the big picture, what does it mean that the populations of red-legged frog, and amphibeans in general, are declining?

PG: Well, global amphibean decline, including frogs, has been an alarming trend in the last ten years. And scientists have launched a series of efforts to try and figure out what is happening with global amphibean decline. There are a number of theories, although none have been entirely agreed upon as the cause. And what is now believed is that there’s a series of interacting factors. One is the loss of our ozone layer, the increase in ultraviolet radiation due to ozone depletion from man-made chemicals. It’s believed to play an important role in amphibean decline. In the case of the red-legged frog, the primary reason for the decline is habitat loss, where the rate of development and urban sprawl in Northern California is huge. And the amount of wetlands that are gobbled up every year in large urban sprawl development projects is extremely high. Additionally, uncontrolled livestock grazing from cattle is another source of declince for the red-legged frog, where the cattle will eat the streamside vegetation and deficate, urinate in the water such that it doesn’t have the water quality that it used to anymore. That’s a serious problem. Loss of habitat, degredation of habitat. Groundwater pumping is a big problem, for urban use and large agribusiness, where these giant wells basically pump the groundwater table so low that the wetlands dry up, another significant loss. So the red-legged frog, it’s believed, the primary reason’s for decline are habitat loss, pesticide appications from agriculture in the central valley are believed to be another source, pesticide drift ? there’s some new studies coming out on that. So the red-legged frog is an example of a species whose primary reason for decline at this point is habitat loss. Other species of amphibeans, it’s not so clear that habitat loss is the primary reason for decline, although it is always an important factor. There’s global climate change, the loss of our ozone layer, increased UV radiation, as well as parasites and even funguses are being looked at as a possible source of some of the possible global amphibean decline. But in the case of the red-legged frog it’s very clear that it’s habitat loss.

ES: What effect would its disappearance have on other animal species?

PG: It’s hard to say because the web of nature is very intricate. It’s very difficult to pinpoint one species’ niche and say: what will happen to the ecosystem if that species no longer occurs there. But we do know that red-legged frogs are an excellent indicator species, or bell weather, for aquatic and riperian habitats in coastal California. We know that if one looks at the distribution of red-legged frogs, and their numbers, as the red-legged frog populations plummet, we see a correlation in the amount of wetlands and aquatic habitat plummeting as well. And there are literally hundereds, and even thousands, of species, as I mentioned, everything from birds, to other amphibeans, to mammals, to plants, that require wetlands for some portion of their lifecycle. And so the red-legged frog has long been considered to be an indicator species, that by protecting the frog and it’s habitat, we will be providing an umbrella for hundreds of other species that occur in that same habitat type. And this is one of the concepts of ecology that’s known as the indicator species concept, and the red-legged frog is a good example of one. I mean one of the things I’ll point out is that endangered species, rare wildlife, are being studied for a variety of reasons, and there’s a variety of reasons why we should protect wildlife. And they range from the moral, scientific, aesthetic, but from the most selfish human point of view, it does not make any sense to drive species extinct because we ourselves may need them to survive. For example, about a half of all modern medicines are derived from wild plants. One example is the Pacific yew tree, a rare tree species in the Pacific Northwest. It’s used to create a drug called taxol, which is used for fighting breast cancer. Another species called the rosy periwinkle, a plant that was believed to be extinct, is now being used as a cure for childhood leukemia. And so the list goes on and on. Science doesn’t know today whether, and if, the California red-legged frog also is the cure for any disease. When congress passed the Endangered Species Act in 1973, the legislative history includes a statement, for all the other reasond why we should protect endangered species, that who knows what scourage one of these species may prevent. And that’s a very telling line from Congress back in ’73. I think that it’s something that remains more true today, that there’s a variety of reasons why we need to protect endangered species, not the least of which is for our own good.

ES: What kind of future do you see for the red-legged frog?

PG: Well, we have a lot of hope for the red-legged frog. As I mentioned, it’s a very charasmatic species, it’s the largest native frog in the west, memorialized in Mark Twain’s writing. There’s broadscale public support for wetlands and for the red-legged frog. And so there are a number of threats on the horizon, but our organization, and a number of other otganizations, dozens of scientists and universities are remaining vigilant in trying to protect and recover the frog. So there’s a lot of threats out there, a lot of dangers. But the bright side is that a large amount of the public has been mobilized to turn things around for the frog. So we’re hopeful that the frog will be able to be recovered.

ES: What are the forces that are threatening the frogs recovery?

PG: Well, we’re very concerned that the building industry, instead of joining forces with the conservation community and agencies to try and protect the red-legged frog, they’re trying to turn the clock back and remove protection for the red-legged frog. And we intend to fight this fiercely. We have moved to intervene in the lawsuit to prevent the de-designation of red-legged frog habitat, and we feel confident that we will prevail in that. It’s very clear that the red-legged frog is imperiled. It’s very clear that it’s very close to extinction. No one is arguing that. The building industry is, in essence, just trying to throw up roadblock after roadblock, and ultimately it’s not even going to serve their interest, because the sooner we protect the red-legged frog and get it back to recovered status, the sooner it will be off the endangered species list, and that’s a goal that we mutually share. It’s just that the building industry appears to want it off the endangered species list extinct, and we want it off the endangered species list recovered. And so we feel that their lawsuits will not prevail. If the building industry does manage to remove critical habitat protection for the red-legged frog, it will be a tragedy, however, we would re-file and continue the fight. Some of these battles go on for a decade or longer. And we’re fully prepared to work to advocate for the red-legged frog for however long it takes.

ES: How many frogs are there currently in the proposed critical habitat area?

PG: That’s not an easy answer. At one time there were estimated to be millions of frogs, and now we’re down to tens of thousands. This is a truly depressing figure: there’s no known populations in the Central Valley, due to agribusiness. It used to occur in 46 counties, but it’s now extirpated, or gone from 24 of those counties. In 22 of the counties, they’re only known from one occurance, there’s only one place left with frogs in 22 of the counties. Only three areas, in the entire historic range of the California red-legged frog, support more than 350 adults. That is a truly depressing number. I’ll tell you where those are: the Pescadaro Marsh, south of San Francisco; Point Reyes National Sea Shore in Marin County; and Rancho San Carlos near Monterrey. And so for a species that once had millions of individuals, to have only three populations with over 350 left is pretty dire. And so how many are out there, I don’t think anyone knows the answer, but it’s in the thousands or tens of thousands.

End of interview with Peter Galvin

Interview with Dr. Robert Stack:

ES: Please tell me a little about yoursself.

RS: My name is Robert Stack, and I have a PhD in Biochemistry from the University of California Davis, and I work with the Jumping Frog Research Institute.

ES: What is the work of the Jumping Frog Research Institute?

RS: Our mission is to conserve and protect the native amphibean species of Nevada, here in California ? that’s our general mission – and specifically since we’re located here in Caleveras County, one of the projects that we want to take on is to work to restore the California red-legged frog to Caleveras County.

ES: So how would you describe a California red-legged frog? What sort of environment do they live in?

RS: They generally live below the snow level, 3000 feet or so in elevation in the Sierra Nevada. It’s the largest native amphibean on the West Coast, the largest native frog west of the Rockies. The adults have a sort of reddish undercolor to their legs and their bellies. They don’t live in streams or rivers. They tend to prefer quiet, shallow waters like lakes or ponds, or like oxbows in creeks and things like that. They’re very attractive frogs, they’re attractive animals and they’re well known because of Mark Twain.

JS: What sort of numbers are there on these frogs, like how many are living in California or other places in the world?

RS: There’s one population that’s known to exist in Baha California, but basically it’s pretty much a species that’s found only in California. Nobody really has any idea how many are left in California, though there are not many. There are only tree populations remaining that have over a couple of hundred each. The remaining populations that are scattered around the state, and most biologists really fear for the fact that the populations are so small that they’re not capable of sustained breeding and recovery.

JS: What are some of the reasons why they’re in the situation that they find themselves in right now?

RS: The reasons why they’re in the situation that they’re in, some of them are historical and some of them are more recent and cummulative. In the beginning, the biggest impact to the red-legged frog was probably the fact that they were over-harvested for eating, to supply the gourmet restaurants in San Francisco around the turn-of-the-century. And then the biggest the problem in the intervening years is after the red-legged frog was essentially over-frogged, frog breeders brought in the bull frog, which was native to east of the Rockies, and tried to raise bull frogs in what was essentially ponds to supply meat, for frog legs. And the bullfrogs turned out to be a very aggressive predator of the red-legged frog. And that situation, over the years and slowly but surely the bullfrog has encroached on the red-legged frog habitat. And then, pretty much all of the frog habitat in California has seen habitat loss and conversion to habitat to, you know, shopping centers and everything else has been pretty devestating to the frog as well.

ES: So I inderstand that there’s a lot of human concern over what defines it’s critical habitat. What are some of the characteristics of the red-legged frog’s critical habitat?

RS: Well, red-legged frog habitat that’s identified as critical habitat is precisely those things that I mentioned earlier that are needed by the frog. One of those, most importantly, is that the frog needs to have a breeding pond, or not necessarily a pond, but a place where the frog can breed. And they also need to have dispersal habitat, because these particular frogs don’t just stay at the water site, you know, where they breed, they’ll migrate within a couple of miles within that location. So one of the big concerns about the critical habitat is that, on the surface, it appears to be quite large, 4.1 million acres. But in fact the amount of critical habitat that’s been set aside for the frog is actuallt much, much, much lower than that, because it only encompasses those areas where there’s a pond capable of supporting the breeding of the frog and then the adjacent area. The big problem of taking the number of 4.1 million acres at face value is that really what it represents is an exterior boundary of the range where the land needs to be looked at. But only those areas that the are deemed essential for the frog are actually considered to be critical habitat.

ES: How would you describe what this critical habitat is like? What does it mean to designate land as critical habitat for the frog?

RS: Well, you’ve hit on a key distinction there, it means different things depending on whether the land is publically owned or privately owned. The rough split, in respect to the frog, I believe is 60% of the critical habitat is privately owned and 40% is publically owned. These are statewide average figures, and of course it varies from county to county. For public land, what it really means is that, say in a national forest which we have plenty of in the Sierra, in a national forest area that’s been declared as critical habitat, it means that the forest service cannot do anything that degrade that habitat or cause it to become such that it would not support the frog. On privately owned land, for the most part, it means bery little. I emphasize “for the most part.” Where a private citizen would need a federal permit, to conduct some activity or another on his land, then the conditions of acquiring that permit are such that a private lans owner could not degrade that habitat and essentially receive that permit. So if the private landowner requires a permit to do something that he or she proposes to do that would be of detriment to the frog, then they’re not likely to get that permit. Usually, however, these things come down to the private land owner would essentially set up what’s called a consultation with the Fish and Wildlife Service. The landowner would meet with the Fish and Wildlife Service representative, and they would say: Oh, fine, you can build a house here, but please don’t do it next to this particular pond. So for the most part, it doesn’t mean much for the private landowners. For large land developers, they do require federal permits that clearly affects their operations.

ES: Getting back to the frog, what are some of the forces that are threatening it right now?

RS: Ranked in order, I would say that number one is the continued loss of habitat. And again, that’s why we think that the critical habitat designation is pretty important. Number two, and this would be my estimation again, would be the presence or absence of the bullfrog. Number three would probably be continued problems with pesticide run-off from homeowners as well as agricultural sources. There’s been some been some good studies out at UC Davis that it’s still playing a major impact on the red-legged frog. I would rank those three factors as probably being the most significant.

ES: How did you make the connection that this frog was indeed Marc Twain’s frog from one of his short stories?

RS: Well, actually Marc Twain does not specifically refer to the species of frog in his story. The reasons that most biologists and historians have arrived at the conclusion the frog in Twain’s story had to be a red-legged frog are the following: One, and probably most importantly is that it comes from a swamp just to the south of Angels Camp. And if you know something about the natural history of California, that pretty much tells you right then and there that it had to be one of two species, either the red-legged frog, or the pacific tree frog. There are two other species found native to California in Caleveras County, but they’re both found exclusively in higher elevations. The Pacific tree frog grows only to be about the size of a half dollar or 50 cent piece [2-3 inches]. In the story, at the very end of the story, the protagonist realizes that he’s been had because his frog’s been fed buckshot. The frog, according to Marc Twain, coughs up several handfulls of buckshot. So the fact that the frog coughs up several handfulls of buckshot pretty much eliminates the possibility that it was a Pacific tree frog because, again, they’re so small that they’re not even capable of swallowing a couple of handfuls of buckshot. So once you add in the final fact that the red-legged frog is the largest frog found west of the Rocky Mountains, and it’s the only frog capable of coughing up several handfuls of buckshot, and the fact that Twain says in the story that he was one of the largest frogs encountered, etc?, you sort of put two and two together, and the fact that there were no bull frogs in 1864 when Mark Twain wrote his story, the process essetially is a little bit of scientific deduction that it has to be the California red-legged frog.

ES: What were the frog populations like back in the days of Mark Twain, and what are they like now, especially in Caleveras County?

RS: Sure, well again there were no biologists at that time that were taking surveys. We don’t even know today what the frog population is like in California. However, we do know from anectdotal accounts, miners and early settlers that there were frogs everywhere. That in every little pond pretty much harbored ponds in that particular day. As far as we know, there are no remaining red-legged frogs in Calevaras County. The last reported sighting of a red-legged frog in Caleveras County, I believe, was in 1979.

ES: What effects are humans making on the California red-legged frog?

RS: Well, basically what we’ve done, we don’t always develop the land that is the most appropriate for development form a wildlife point of view. So, often times these issues are characterized on the basis of: there will either be development or development will be blocked. And in my mind, that’s pretty much the same sort of false dillema that advertizers like to put to you: you will buy brand X of laundry detergent or have dirty clothes. And obviously you can chose from any number of laundry detergents. One can chose from any number of ways of developing land. Now, to me the issue is not whether or not we’re going to develop houses or stores or industrial facilities here in California. It’s one of giving more thoughtful attention to planning, and giving thoughtful consideration of what sites are more appropriate for development. There’s no reason why we have to put development right into sensitive estuaries and sensitive aquatic and riperian habitat. And, too often, that’s the way that these issues get charaterized. And I don’t think that we should be building new homes for humans on top of the homes or potential homes of our native frogs that are in trouble. We can just go a short distance away from the creek or the pond or what have you, build our home, and the frog can still have its home. So with respect to humans and their impact on frog habitat, I think the issue really comes down to: can we as humans develop sensitively and intelligently enough that we don’t destroy the homes of our frogs while we create homes for ourselves. We’re intelligent enough that we can work things out to have both.

ES: What would it mean if the California red-legged frog was to disappear? I understand that amphibeans are declining worldwide.

RS: Well, these are the kinds of questions that ecologists spend a lot of time thinking about. And the fact of the matter is that nobody really knows for sure. We know that frogs play an important part in the ecosystem. The red-legged frog is a staple dietary item of herons, snakes and things like that, so clearly as the frogs go, these other critters will be impacted. Whether they can pick up alternative food sources, nobody really knows. So many times there are unanticipated consequences from the loss of species. Biologists today think that it was the loss of the passenger pigeon, which pretty much is responsible for the big increase in lyme disease back east, because those pigeons used to compete back east with mice and rodents for the huge crop of acorns that were produced. Now that those birds aren’t competing, 100 years later the mice populations have exploded, the tick populations have exploded, they use the deer as an alternative host, and we have Lyme disease as a consequence. So, ? in spite of the fact that we seem to think that we’re very intelligent – our vision does not extend 100 years to see what are the real repercussions of the actions that we take today. I think it was Emerson ? but I’m not sure ? said that the first rule of intelligent tinkering is to save all the pieces. And I really think that we need to take that advice to heart and do what we can to save the pieces so we can try to put things right when we’re smart enough to do so.

ES: What kind of future do you see for the California red-legged frog?

RS: Well I hope that it’s a future that is not one that’s tied into the court system. My hope is that because this frog is pretty famous, thanks to Mark Twain, people will come to realize that this frog, like all other creatures, has an important role to play in the functioning of healthy ecosystems. So I think that because this frog is well known, that anount of attention could insure that the frog does have a future. More people wrote in and sent comments to the Fish and Wildlife Service for this species than any other species ever that’s been covered in the Endangered Species Act. About 90% of those letters were positive and supported reocovery and reintroduction of this frog. And I think that in some way, clearly this frog has touched the imaginations of many people and many, many people want to make sure that it is still around. The imaginations of any future Mark Twains, six years old right now and getting inspired to write some short stories.

ES: What are some of the goals of the Jumping Frog Institute?

RS: We work to insure a future for the native amphibeans of the Sierra Nevada, and that’s really it in a nutshell. The frog is just one of the species that is native to the Sierra Nevada. Many of the frog and salamander species of the Sierra Nevada are also in trouble for different reasons. The mountain yellow-legged frog is only found in higher elevations and in areas that bullfrogs cannot even live, because it’s too cold. The problem with the mountain yellow-legged frog is the overstocking of the high elevation lakes in the Sierra Nevada. We’re working closely with the California Department of Fish and Game to modifiy some of the stocking programs, lakes that still have sizable frog populations are not overstocked with non-native species and essentially wipe those frogs out. And we work with them in a very cooperative way. They do seem to care about this frog and they want to work to resolve these problems. The foothill yellow-legged frog is another frog in the Sierra Nevada. It’s not in such good shape, though, and we’re working with various federal agencies right now in a more cooperative way to get some changes made to some policies that we thimnk negatively impact the yellow-legged frog. Our focus is clearly on frogs, because of limitations in what we can do. We have to choose what our involvement will be and limit it accordingly, as opposed to trying to do everything and not getting anything accomplished. So we’re pretty much focused on those three frog species right now, the mountain yellow-legged frog, the foothill yellow-legged frog, and the California red-legged frog, which at this point has turned into a big court battle.

ES: Thanks so much for speaking with me today. Is there anything else that you’d like to add for the listeners of Earth and Sky?

RS: Well, I just think that everyone should really think about what kind of future we would have without frogs. And you know, the old saying about thinking globally but acting locally, I think that everyone really needs to think about that in the context of their own frog problem. You mentioned earlier that frogs worldwide are declining. Every frog that’s declining is declining for a reason. And I personally can’t imagine a future without frogs. And I would just ask people that if they can’t imagine a future without frogs, then try to do something about it. And that’s what we’re trying to do here in our own backyard.