Funny, just after I waxed cathartic about figuring out that one species was actually two, today I experienced a kind of reversal. Shrub frogs of the genus Philautu in the Philippines are, in my opinion, nearly impossible to tell apart. In my experience, unless you hear their mating calls, you don't stand much of a chance of being able to identify them‚ because they are so similar in physical appearance. Then, to make matters worse, all their calls sound like "rattles‚" or "crunches." Sometimes one species will go "Crunch!" and another will sound like "Cruuuunch," but they are all variations on just a few themes. It's all very confusing.
For the last several days it has been misty and wet, without steady rain. We have encountered two apparent species of Philautu, one large and another small, with a pointy snout. I was pretty sure: the big "species," consistently has had a greenish color scheme and the little one yellow or brown.
Anyway, today it rained. Hard. Everyone retreated to their tents and hunkered down for the afternoon, it poured and poured, the camp frothed up in chocolate brown mud and, as it got dark, I finally heard a new frog call nearby -- could it be one of the Philautu species? I turned on my headlamp and crawled through the bushes behind my tent and was confronted with a pair of frogs in amplexu (the male grasping the female during mating) on the leaf of a shrub. In just a glance I realized my mistake the big frog‚ was the female and the small frog was the male and the two were actually the same species.
Sexual size dimorphism, or the discrepancy in body size between males and females, is near universal in frogs around the world. In almost all anuran (frogs and toads), females are larger than males, sometimes strikingly so. In a few very special groups, the males are larger than the females. Sometimes the appearance between the sexes is so marked that even the experts get confused and name the male of a species one scientific name and the female another. These shrub frogs fooled me for a week, but at least it finally rained and I didn't make that mistake.
Today was a cathartic day in my own personal journey in studies of Philippine biodiversity. The story starts in 1991 when, as an undergraduate student at Miami University, I joined my first biodiversity inventory expedition to the Philippines. This was a great experience for a 22 year old, and my life took an immediate and irreversible turn (for the better) towards my passion for the study of life in islands archipelagos. But more to the point: in 1991 we surveyed the southern slopes of Mt. Busa in South Cotobato Province (southern Mindanao). The southern Philippines was a bit wild back then and a major commercial logging operation was focused on logging out the remaining huge, closed-canopy, forests along the south coast of Mindanao. Valued at $10,000 per trunk on the Japanese timber market, the hardwood logs that came down the slopes of Mt. Busa made two Kiamba area families extremely wealthy…and changed the landscape and biodiversity of the immediate area forever.
In 1991 I took this image of a WWII MacArthur era weapons carrier truck, converted to a logging skidder, carrying out the massive trunks of the last giant trees from the lowland forests of southern Mindanao. The environmental devastation imparted by this kind of logging is clearly evident; in this picture a logging truck drives through a small stream in a denuded area where a few days before I had collected frog specimens in what had then been pristine forest.
On that trip, justifiably convinced that all local frog populations were going locally extinct, we mounted a salvage operation and collected specimens to the very legal limit allowable by our permits. We anticipated that no animals would survive the holocaust of large-scale commercial logging in that drainage on Mt. Busa and we did the best we could to document every resident species’ presence in the form of preserved specimens, before the record of their existence had been erased forever.
In the middle of a large series of preserved frogs, I unknowingly preserved a single specimen of what I have, over many years, come to believe is new species, still unnamed and unknown to the world. At the time, the slight morphological differences did not impress me and I misidentified the specimen as one of the locally common species. Years later, during my Masters work at Miami University, I showed that this one individual was genetically distinct…but I hesitated to name it because I had only that one specimen…
Now, 21 years later—last night—I finally collected another specimen and knew in an instant what it was…as I flash backed to my memories of Mt. Busa in 1991. How could I have ever doubted myself? This frog obviously is a new species of great conservation significance.
After decades of biodiversity work, so many species discoveries, years of contributions to conservation efforts and student training, I reflect back on so many arguments with my fellow “conversation” biologists on the topic of faunal collecting and the age-old tradition (standardized by Linnaeu) of preserving specimens for describing and documenting biodiversity. Some individuals, understandably abhorring the killing of animals for any reason, frequently speak ill of the practice of collecting and preserving specimens for science. They argue that it is no longer necessary, that it is unethical, or that scientists may actually contribute to extinction of a species by removing a few individuals from the gene pool. Given the unceasing pace of habitat destruction brought about by logging, mining, and gradual conversion of forest to agriculture, there is absolutely no doubt in anyone’s mind that the real threat to biodiversity is habitat loss, not occasional specimen preservation by scientists. We can debate about all the possible causes, but at the end of the day the fact remains: when we cut down the forest, the organisms that depend on it will go extinct. If we cut down all the forest in an area in rapid succession, there is little to no chance for survivors.
For my part, I’m reminded of how important it is to document biodiversity assessments with vouchered specimens. I’m relieved that I unknowingly collected and preserved that large series of frogs in 1991, before their population’s extinction at the hands of the loggers. We now know that there once was a population in the previously forested area, which has now been converted to scorched, arid, grassland. And in the process we discovered a new, unknown species, albeit by mistake. It has taken me 21 years to convince myself of its distinctiveness, but today I am vindicated. And another population (in a protected area) has now been identified, with positive prospects for the continued survival of the species. Finally, the Philippines now has 110 + 1 species of amphibians.
My new hero is our field camp assistant, Pedro, a.k.a “Baba.” Every day or two Baba brings me a couple of animals: a miniature forest rat, a bird, a giant water bug, a sail fin lizard, snake eggs from inside a log; whatever he finds. Invariably he proudly presents the new catch on the end of some plastic string and we communicate in grunts and gestures because he speaks only Bisaya and a local indigenous language and I speak only English and Tagalog. Baba is very adept at setting snares that put our fancy field gear to shame. He has produced more species of mammals than all of the rest of us combined…but the best part is his enthusiasm for each variant he finds. Baba uses his 2-foot, extremely sharp, bolo (macheté) for everything: cutting paths, fixing his sandals, opening cans of food, fixing snares….one popular camp joke goes like this. “Hey do you know what Baba uses to comb his hair? A bolo. Do you know what he uses to scratch his back? A bolo…Do you know what he uses to brush his teeth? A bolo!”
Today Baba brought me a folded leaf with a very strange creature contained within…as I carefully unfolded the leaf and got a glimpse of its contents I thought, “OK Baba, thanks for the worm….wait, is that a centipede? Ah, I know: it’s a blind snake…wait, no way! Is that a Dibamu??!”
Dibamu are some of the most enigmatic and poorly known lizards in the world. They certainly do not look like lizards. They are legless and unless you get a close look at their head (and see eye spots and their mouth), you might mistake them for a worm. Modern herpetologists have debated their evolutionary affinities for decades. They are seldom collected in the Philippines and, according to current taxonomy, Philippine populations are grouped under a species that extends from Asia to New Guinea (an arrangement that I find extremely unlikely, suggesting to me that this specimen is unknown to science). It’s only the second time that I’ve seen Dibamu in the archipelago…what a thrill! Thanks Baba!
It’s always interesting to see how people adjust to life in camp when first arriving in the field. I am particularly intrigued by what appeals to new students—what interests them, which animals they like, what questions develop. It’s a finer point, but these initial impressions can have a profound impact on someone’s life. It is that passion for the organism that not only has the potential to inspire someone to take up a career in biology, but which may also sustain them for five or six years of graduate school or whatever higher training they may undertake.
This year, as we embark on the 100th year anniversary of herpetological collaboration between the University of Kansas and the National Museum of the Philippines (actually titled the Philippine Bureau of Science when Dr. E. H. Taylor first travelled to the archipelago in 1912), I am accompanied by a new student, Kerry Cobb, who has just earned his bachelor’s degree from KU and has been excitedly looking forward to this trip (his first time out of the States) for the last several months.
Kerry is already an accomplished field biologist who has done very hard-core, months-long, back-country fieldwork on salmon ecology in major parks in the western U.S. He wasted no time fitting right in to the group social dynamic of our all-Filipino field team, going out every night to catch amphibians and reptiles with the herper, cracking jokes with the mammalogist, poking fun at the parasitologist for their study of very gross things, and in general staying amused and in good spirits. On our second day he discovered that the nearby river was full of tadpoles and went back to his tent with a purpose, produced a pair of swimming goggles, and spent the next couple of hours swimming back and forth across one of the larger pools. He then triumphantly came back to camp with several goldfish bags of tadpoles and spent another hour or two sorting the larvae into batches corresponding to species. A day later, after he had time to think about it a bit, he did the math and perceptively pointed out that although we had encountered six or seven species of frogs in the area, there were nine species of tadpoles present in the site. What could be going on here?
As it turns out, the idiosyncratic reproductive cycles of the various frog species present at any given site and time is always in flux. Clearly there were two or three additional species breeding here a month ago, and while we have not yet encountered the adults, we know they were here because of the presence of their larvae in the river. Perhaps the adults have dispersed back into the forest at this point, may have gone under ground or up into the tree canopy…we just don’t know. “Well, how do we identify them?” Kerry asked, “And are there any published papers that we can use to key out the tads?” Unfortunately, the state of knowledge of vertebrate biodiversity is so underdeveloped in this part of the country that those kinds of resources do not yet exist. The best we can do is sort the tadpoles to apparent species, preserve a few of each kind for future studies back in the museum, and take tissue samples for subsequent DNA identification. When we get back to the lab in several months, we can sequence the DNA of all the adults and tadpoles for a common gene fragment. Then we can match them up and identify the tadpole of each resident species….but the mystery tads will remain a mystery until an adult (possibly from another part of the island, or the next island over) can be sequenced and matched to their genotype. Doing this systematically for the country, trying to match all the larvae with all the adults (there are more than 110 frog species in the Philippines), would be a great first step for a graduate project and constitute a major contribution to Philippine herpetology. Hopefully a bright student with a passion for tadpoles will emerge. I can see the first kernel of curiosity in Kerry; hopefully someone like him will be inspired to take on the Philippine tadpole challenge. —Rafe