14

Wok bilong ol pik

Exploration and discovery have always been fundamental to my fascination with the natural world. I relish being outdoors just looking for cool stuff. I have been extraordinarily lucky in how much of my time I have been able to do just that. While pursuing my doctorate, I was privileged to live and work on the world’s largest tropical island, New Guinea, for nearly four years. That time, the people and places I came to know, and the experiences I had still inspire a deep sense of awe in me to this day.

Situated just north of Australia at one end of arguably the most interesting and important biogeographic transition on the planet (in the demesne called Wallacea after Alfred Russel Wallace, the cofounder of the theory of evolution via natural selection), the island is a field biologist’s dream. After months of preparation in Coral Gables, Florida, at the University of Miami, I was set to journey to the Wara Sera Research Station inside the Crater Mountain Wildlife Management Area, situated between the provinces of Chimbu, Gulf, and Eastern Highlands in Papua New Guinea (PNG). I had built up an overload of excitement and anticipation at being able to conduct field research for my doctorate in one of the last remaining truly remote rain forests on the planet. My initial delight and joy, however, was soon to change.

The jungle in many parts of New Guinea is dripping wet: a haven for biodiversity of all kinds. With my field site receiving almost 7 m in rainfall annually, amazing adaptations possible only in hyper-humid conditions abound (e.g., the evolution of parental care in frogs with direct development). Terrestrial leeches do extraordinarily well there and seem to be omnipresent in Melanesian rainforests. We entertained at least seven different species of leeches on a daily basis, with unnerving abilities to enter orifices, latch on, and get a full feed without the host being any wiser. It was a veritable hothouse of other parasites and tropical diseases as well. Everyone fixates on the ones you can die from (e.g., malaria, lymphatic filariasis, systemic septic infections, and meningitis), but it was the leeches that had the largest impact on my daily routine. Minor nuisance though they are, since they do not transmit human diseases, they make you bleed profusely for extended periods because of potent anticoagulants. They also create itchy, bloody sores that easily become infected when scratched, leading to double whammy when coupled with the prevalence of a tenacious skin fungus (grille, or Tinea imbricata cf.) that left open, festering fissures from toes to ankles. At one low point, I had dozens of open sores below my knees and a systemic septic infection that sent bluish streaks up my legs. The preponderance of novel bacteria, fungi, viruses, and parasites had my immune system on the run. My romantic idea of fieldwork had been replaced by a kind of dread and worry about my mental and physical health in those first few months of fieldwork. Luckily, and with a bit of help from my friends and assistants, I emerged after my trial by infection and had a wonderful, albeit challenging, experience.

One of my first memorable New Guinea experiences in the rain forest happened while I was recording frog calls near the field station. It was raining (surprise!) and I had my expensive recording equipment out to record the frogs. Back in 1995, we still used cassette tapes to record frog advertisement calls—a complicated affair compared with today’s smaller, lighter-weight digital media devices and instruments. I had an umbrella in one hand, the recording equipment slung around my neck, a fishing vest and fanny-pack full of instruments, and a sensitive microphone in my other hand outstretched over a microhylid frog perched just a meter off the forest floor. These frogs don’t need water for breeding and instead lay their eggs in shallow, cup-like cavities in the soil. This particular male was almost directly above his prepared oviposition site calling for all he was worth. I had to switch off my headtorch in order to elicit the frog to call and record without disturbing the frog too much (i.e., enough to affect its reproductive behavior). Because I was relatively new at recording frog calls, I needed a worksheet for all the data I wanted to record, and I had an array of instruments including a thermometer, GPS unit, hygrometer, watch, and altimeter.

While distracted with recording data in the dark, I was caught off guard by what sounded like a very large animal noisily and rapidly approaching. I hastily went through a mental checklist of all the possible critters that would make that kind of racket and had it narrowed down to human, Cassowary, or wild pig. There aren’t that many large animals over 10 kg in the forest of New Guinea, much less any that would be noisily traipsing through the forest at night. Isolated for millions of years at the northern edge of the Australian plate as it slowly rotated counterclockwise and approached what is now the equator, the proto-island of New Guinea accreted several smaller island arcs: biogeographic misfits across the vast waterways that divided Laurasia from Gondwanaland millions of years ago. Large placental mammals (outside the recent influx of humans, pigs, and dogs) have never been present, and the larger marsupials mostly went extinct. Mostly.

It was a Papuan forest wallaby that bumped into me as it hopped through the forest, surprising us both, I think. The knee-high marsupial barely paused as it rebounded off my leg and kept right on hopping through the forest. I laughed out loud and scared the poor thing even more. I mean, it was super cute and dopey, and as it hopped away I couldn’t help thinking about how and why different lineages of animals succeed and diversify or get outcompeted and go extinct. What was the wallaby doing hopping around at night, bumping into me?! I was giddy from the flood of endorphins and adrenalin but also relieved. The incident was probably funnier to me than it should have been because of the near panic I experienced at something unknown noisily and quickly approaching me in the rain forest in complete darkness. My laughter was self-deprecating and short-lived. I had work to do and so got back to recording the frog call.

Not even two months later, I had settled into a daily routine with my local assistants, people of the Pawaia language group who mostly live in and around the villages of Haia, Wabo, and Soliabedo. Working in PNG meant being a guest of the local people and understanding their tight connection to the land and its biodiversity. While they were training me in the ways of the rain forest, I was training them in standard scientific field sampling methods, which encompassed plots, transects, and identification of organisms we would find. These research methods have now become part of the local communities’ array of expertise that enables them to rely on intact biological and cultural systems for their livelihood. We would rise early to conduct 5 × 5 m leaf-litter plots to find frogs, snakes, and lizards (mostly frogs) to establish a baseline for the long-term biodiversity monitoring project that we were setting up in the wildlife management area. Then, at night, we would look for frogs along transects in the forest. Ordinarily, we did four leaf-litter plots each morning and one or two visual encounter surveys after dark. With both day and night activities, the fieldwork was exciting and fun but grueling. The terrain in that part of PNG is mountainous and rugged in a way that I have seldom seen in other places, with incredibly steep slopes that are challenging to hike. Typical days included multiple steam crossings, elevational changes in the 1000 m range, and a dazzling array of biodiversity.

The local people that I employed to help me do fieldwork called the leaf-litter plots wok bilong ol pik, which translates into pigs’ work, an apt description of being on your hands and knees in the muddy forest floor. From the little gems we would find during the leaf-litter plots (e.g., scorpions, centipedes, fungi, fruits, seeds, Cassowary poops, spiders, ants, orchids, ferns, and the focal target organisms), the mornings were the best times to get to know my hosts and coworkers. We enjoyed each other’s company tremendously, despite (ok, maybe partially because of) getting filthy every day sorting through the detritus, logs, leaves, and decaying vegetation of the forest. I learned a great deal about the forest from the Pawaia. They told me interesting facts and related stories and myths of spirits and supernatural explanations for some of the things we regularly saw in the forest.

We often found Cassowary droppings during the leaf litter plots. Cassowaries have been called the most dangerous bird and implicated in human deaths and dismemberment. They are big (almost 6 ft tall and easily >120 lb) and have enormous poops full of all kinds of seeds from their frugivorous diet. Old Cassowary poops were fascinating to find, not just because of the sprouting seedlings but also the impressive seed armor (endocarps) in which many of the plants encapsulate their seeds to protect them from either passage through the Cassowaries’ digestive system or the rat and bandicoot seed predators. Whatever the driver of the heavy investment to protect the seeds, they were an amazing display of evolutionary adaptation and a source of constant wonder at the merging of form and function.

At night, we used transects to sample frog activity, diversity, and abundance. This typically meant that three local assistants and I would walk a prescribed trail for an hour, looking for frogs; catching, measuring and identifying them; and then releasing them afterward. This work was also a delight, with opportunities for discovery every time we went out. I always tell people that the best time to be out in the forest is at night, when all the cool stuff comes out. On New Guinea, this was especially true. Not only would we find frogs and snakes, but also tarantulas, scorpions, stick insects, geckos, bats, tree kangaroos, and many strange birds like frogmouths and nightjars. We walked slowly at night, each of us looking for frogs on the ground and up into the vegetation. It was at night that we would find the egg-brooding frogs that lay their eggs on the underside of live leaves a few meters above ground. These frogs guard their eggs only at night, rehydrating them before leaving them unprotected during the day. We also discovered one of my favorite behaviors to have ever witnessed: froglet transport. Although the local people knew about this and it had been rudimentarily described, no one had been able to see it enough times to document and measure the behavior.

That all changed in 1995. I was returning from a visual encounter survey in a light drizzle when I saw a strange shiny blob on a fallen branch that had almost crossed the trail. At first, I did not know what I was seeing. I thought it must have been an injured adult frog. Sometimes we would find animals that had been injured, escaping a predator but left somewhat disfigured or missing limbs. But this animal was symmetrical and much wider than a normal adult frog. It reminded me of glass sculptures I have seen—smooth, fat, and shiny. Then I realized that it was an adult frog covered in tiny froglets! It was one of my favorite frogs at the site, Wandolleck's Land Frog (Liophryne schlaginhaufeni). I stared for a few seconds, thinking what serendipity! This was an amazing thing to see in the field, and I felt both amazement and wonder about how such a behavior could have evolved. I could not contain my excitement and had to let my assistants, Lamec, Peter, and Selau, know what we had stumbled across. They caught my enthusiasm and after a brief whispered conversation about what to do next, I asked them to stay with the frog, not to disturb it, but track it if it moved. I would run back to camp to get my camera. When I returned, the frog had moved only a few centimeters, and I was able to count the number of froglets and take many high-quality pictures. We even noted clear azure punctations across the dorsal surface of the froglets—something distinct from the adults. I was psyched; this was a major discovery that I would be able to study in great detail.

That chance observation enabled us to set up a longer-term study with detailed methods to collect data on the novel behavior, which we ended up documenting in three species at that site. It was to be the basis of my first scientific publication and would turn out to be an important contribution to the understanding of not just reproduction but of parental care behaviors in frogs. It is these kinds of discoveries that make every opportunity to be in the field exciting and that keep field biologists on our toes. You never know what you might find.