12

Flying Southward Thirty-Three Degrees to Catch More Frogs

In 1975, as my seventh year at Mississippi State University approached, I planned a sabbatical in the Amazonian jungle near the equator at Santa Cecilia, Ecuador. Marty Crump gave me a brief introduction to this new world, and a couple of nights after she left I noticed the absolute brilliance of the stars reflected in a puddle of water on the dirt runway. When I lay down for a longer view, I saw a shiny satellite zipping across the backdrop of stars, and when my focusing knob got twisted just right, the Southern Cross snapped into view about halfway to the horizon. With the calls of several frogs providing background music, I realized just where I was positioned on my tiny home planet.

Ildefonso Muñoz’s place, dubbed Muñozlandia, on the north bank of the Río Aquarico, had served as a research base for several researchers, and many frogs and a couple of plethodontid salamanders and caecilians were waiting to be found. Señora Blanca Muñoz and a Quechua girl named Ilysia fed me from a very interesting menu.

Humorous happenings arose during the resuscitation of my undergraduate Spanish. Recall that an i in Spanish is pronounced like a long e in English, so when a Spanish speaker chooses to use the common curse word that is an anagram of this, it sounds like he is talking about a piece of paper, a sheet. One evening Ilde asked me if I needed some clean sábanas. I told him that I did not know that last word.

Oh, he said, and explained with widely spread, upraised arms, Blanco y grande, ropas para su cama (white and large, clothes for your bed).

Oh, okay, I responded, sheets.

He frowned his disgust and admonished me loudly with No, Ronn! Not is shits!

Si! When I spelled it out loud, he mused more quietly.

Ahhh, sheets, a good to know!

Because nothing was known about the life history of Nyctimantis rugiceps, a large, garish hylid that breeds in bamboo stumps, it was a prime target. Their calls told me that they were not rare, and one night I quietly worked through a bamboo thicket until I could feel the vibration of a calling male when I lightly touched a specific stalk. I marked the stalk so that I could return the next day with an axe. When I got back on the path, I turned around to see where I had been, and right behind where I had just stood there was a Nyctimantis sitting on the edge of a bamboo stump. I made the very painful decision to leave it alone with the hopes that it would lay eggs, and when I checked the next morning, there was a large number of eggs in the water in that stump—all dead! I never found another adult.

About a 10-minute walk west through the jungle, there was a small forest pond dubbed Lago Perdido (Lost Lake). It was about 40 by 20 m, and many frogs bred there. I avoided the western end because there was a small grove of palms with hordes of long, narrow spines, and several young Caiman crocodilus sunned along the edges. I caught a male microhylid Ctenophryne geayi strictly by accident. The bank of the pond had a very thick deposit of leaves, and one evening I was sitting there waiting for it to get dark. I jumped when a frog called from beneath the leaves right between my feet and my butt. I heard it call several times until I saw a leaf vibrate about four layers down before I grabbed it.

Phyllomedusid frogs can grasp with their hands and feet, and the frantic ovipositional antics of the skinny legged Phyllomedusa vaillantii on leaves above the water were quite comical. Their oddly shaped tadpoles with a mobile tail tip and a ventral fin taller than the dorsal fin hung in midwater in a nose-up posture. On one night, a weird microhylid thing happened that I eventually saw repeated only one other time with a species of Microhyla at a similar pond in Vietnam. Many individuals of one species of Chiasmocleis were moving into the pond from one direction, and before I left that night a large area at the western end of the pond was covered with their floating films of eggs. I still have no idea why either of these migrations occurred on one specific night.

I sometimes walked out on a fallen tree trunk that spanned the width of the pond. Phyllomedusa tadpoles were hanging in the water, and strange, eel-shaped beasts stood upright with their tails stuck in the bottom. I bought some small fish hooks the next time I was in Quito, and one of those beasts instantly took the bait. I eventually found out that it was a synbranchid eel; the gill slits that are fused into one midventral opening was the diagnostic trait. Just as I have often wondered about Siren (two-legged aquatic salamanders) in small, isolated ponds in Mississippi, I wondered how these fish got into that isolated pond.

One night on my way back from Lago Perdido, I walked out into a long dugout canoe that was beached on the mucky bank of a woodland lake. As I looked along the canoe, I saw a turtle pushing aside the plants on its way to the surface to breathe. I got balanced and ready, and luckily at the last moment, I realized that I was about to grab the head of a large electric eel (Electrophorus sp.)! It made a loud gasp when it took in a breath at the surface, and I expelled mine in return. Another time I walked down the sandy stream that flowed into that lake to check out some frog calls. The frogs stopped calling, so I shut off my light and waited. When I eventually turned on my light, to the side, there was a pair of large reflective eyes on the sandy bottom not far from my feet. I automatically assumed that it was a young caiman, but I finally realized it was a freshwater stingray. The manager of the parts depot for one of the drilling companies, whom I had met, had shown me the large toxic spine on the tail of one of these fish. When I jabbed it on the nose with my machete, it disappeared in a cloud of sand.

I never swam in that lake because I had been told that the piranhas would attack if they were breeding. I also never swam in the river because it was way too cold, and there were small catfish (i.e., candiru) that are parasitic on the gills of other fishes. They find their way into the gill cavity by being highly sensitive to ammonia, and small larvae can swim up a man’s urethra for the same reason. One of the military officers suffered that fate while I was there.

Comments of admiration are added about some large, musical birds that often sang me awake at daybreak. A tall, remnant canopy tree behind my house was the nesting site of a group of Oropendolas. These large relatives of North American orioles warbled a constant choral of burbs, gargles, and farts while hanging upside down to weave their long, hanging nests.

Once in a while I would catch a bus toward Quito in the afternoon and then get off just before the Andean summit. The shiny, black adults of the bufonid Atelopus ignescens in a nearby stream looked like they had been carved out of licorice. Their strange tadpoles with bellies modified as suction cups were stuck all over the rocks in fast water. On my first visit to a smaller, steep stream, I saw nothing of interest except for a row of red dots aligned along the bottom of a small tree branch farther uphill. The next time I had stable footing, I was face-to-face with a large treefrog that was bronzy brown top and bottom, including its eyes. All its toe pads were bright red. Bill Duellman and I eventually described this frog in 1973, and it is now known as Hyloscirtus lindae in reference to Duellman’s wife, Linda Trueb. When I got back on the road, a fellow from Chile with his strange Castilian pronunciations of Spanish picked me up. He gave me one donut of a dozen that he had for a girlfriend.

In 1973, John Lynch and Bill Duellman described several centrolenid frogs from a stream farther down the slope. Such large diversity in a single stream is uncommon, and one of those frogs was atypically brown. I saw several species of hummingbirds in their nightly hibernations on limbs over the water, but I did not see or hear even one centrolenid. I finally sat down and dosed against a tree until daylight. I had learned how to find centrolenid tadpoles in Mexico, so I walked along the lower, fairly level part of the stream until I found a leaf mat behind a small log that was projecting into the stream. Centrolenid tadpoles are elongate burrowers with tiny eyes, and many are bright red. When I dipped into that leaf mat, I saw many squirming red tadpoles that I could divide into five morphological types, but actual identifications were never possible. I did collect specimens of another hylid frog that looked odd to me. Hyloscirtus torrenticola is the other species that Bill Duellman and I described in 1973.

Bothrops atrox was reported to be the most common snake at Santa Cecilia, and I never saw even one. Frog people don’t see snakes, and snake people don’t see frogs! One day I heard a big commotion when some military officers were swimming in the river, and when I went to investigate, I found a young Eunectes murinus (anaconda) about 2 m in length. I was quite a hero when I grabbed it. Then I wondered what I was going to do with a large, heavy snake coiled into a ball around my left hand. I managed to uncoil it enough to hold it against the wall of my house until it relaxed with its tail touching the ground. I marked the position of its snout and thus had an estimate of its length. I took it back to the river and released it when no one was around.

The frogs at Santa Cecilia could be partitioned into those limited to primary forests versus those that occurred in disturbed areas. The hylid frogs in the Dendropsophus leucophyllatus and the Scinax ruber groups were common in disturbed areas. The long-legged hylid Boana lanciformis bred in the shower reservoir almost every night, so tadpoles in the soap were a herpetological addition to every shower. The microhylids and some phyllomedusids were limited to primary forests, and in both cases the frogs were found in specific areas that looked just like the rest of the habitat to me. The small green centrolenid Teratohyla midas was limited to a small grove of six banana trees growing in water along the runway, and I still have no idea why my attempts to rear that strange tadpole always failed. Likewise, the grumpy leptodactylid Ceratophrys cornuta bred in one small pool near the end of the runway. I concluded that the frogs recognized a lot more structure of tropical forests than I did.

I felt like I was decently adept at finding frogs, but there were some species that I never encountered. Who knows how populations of tropical frogs vary through time or how my searching methods biased what I found. I often book mental trips back to Santa Cecilia, but knowing that the area where I worked is now covered by an oil palm plantation definitely sours those visits. I cannot return to the past, but I hope the frogs have it figured out.