23

Crying in the Rain, in the Middle of the World

The 24th of February 2022, about 1800 hours. The dusk announces a dark night, and a soft drizzle embraces every living being. I am outdoors, in a restored montane forest of the Los Chillos valley in Quito, Ecuador. A chorus of Cuico frogs (Pristimantis unistrigatus) have begun to chant, and the wrack tac tac of a couple of male Gualataco Marsupial Frogs (Gastrotheca riobambae) heralds the coming rain. After walking a little ways from the forest, I find myself next to a fast-flowing stream, where an amplectant pair of a harlequin frog, the famous Jambato (Atelopus ignescens), walks at its shore—the couple is attempting to find the perfect place to deposit a clutch of eggs underwater. Nearly 10 m from the stream, I hear the calls of three other species of frogs once abundant in Quito (now nearly extinct): a Guard Marsupial Frog (Gastrotheca pseustes), Quito Rocket Frog (Hyloxalus jacobuspetersi), and Buckley´s Glass Frog (Centrolene buckleyi). This walk is part of my routine and enviable life. I am lucky to be in the middle of the world, in a privileged equatorial hot spot of the planet Earth, the most sapodiverse country. Ecuadorians know that our country is a dream place for scientists, ecotourists, and frog lovers.

This magical scenario triggers memories of my first childhood encounters with frogs, more than half a century ago. The frogs I referred to above represent once common genera of a typical amphibian montane community in the Andes. In fact, at the end of the 1960s these genera and species were so abundant that for curious children it was irresistible not to take them home. Gualataco tadpoles were the first guests of our homemade aquariums, from which we discovered frog metamorphosis. The tails of these tadpoles had long been a source of medicine to cure the red of the eye (i.e., conjunctivitis). Edward Whymper, an Englishman and the world´s father of mountaineering who climbed mountains in Ecuador in 1880, observed and collected the Gualataco and reported on its abundance: In the vicinity of the town of Machachi we saw thousands, and must have heard hundreds of thousands of frogs … and in the evening their music was so loud as almost to interfere with hearing when walking out (Boulenger 1882).

My childhood and early youth were full of discoveries, joy, and adventures with frogs in the Ecuadorian Andes. For example, and with some shame I must confess, I discovered, at about eight years old, the damaging side of the greenhouse effect when I collected dozens of glass frogs and placed them in closed plastic bags, fully exposed to the sun—and they died within a couple of minutes. What a fatal destiny in the city of Guaranda, the little town where I was born, located at the foothills of the Chimborazo volcano, the mountain where Humboldt, the father of ecology and biogeography, gathered data and received inspiration for his revolutionary scientific ideas.

Guaranda and the Andes have had a profound impact on my life as an amphibian biologist, taxonomist, and conservationist. As a kid, I discovered my first species of frog, a cousin of the black Jambato. One day, I was playing at the river margin and to my surprise I saw a bright red-orange frog (Puca Sapo) walk nearby. Neither its color, nor walking locomotion, nor day activity had been included in the only scholarly books I had at hand: Escolar Ecuatoriano and an encyclopedia depicting animals (frogs and toads were supposed to be green or brown, jumpers, and nocturnal). At first, I was disappointed to find that nothing I read or saw in the books seemed to fit the morphology or natural history features I observed. However, I was soon thrilled by the possibility of having found something new. About three decades passed before, in 2002, I published a paper describing this species (Atelopus guanujo) as new to science. Needless to say, it was a superb journey after studying general biology and later specializing in the systematics and ecology of amphibians at the prestigious University of Kansas and being mentored by two of the most dedicated and prolific amphibian biologists, William E. Duellman and Linda Trueb. Duellman and his students have been the taxonomists who contributed most to describing the astonishing number of 655 species of frogs from Ecuador, a country in which about 12 new species are being described every year—and no less than 200 remain yet undescribed.

The discoveries of species are still a work in progress, and more taxonomists and conservation biologists are urgently needed, given that the sixth mass extinction is occurring faster than expected and is converting some of us into forensic taxonomists. Sadly, the description of the Puca Sapo came nearly too late: in 2002 this species was presumably extinct and the last individuals were seen in 1988. Its disappearance was part of sudden declines, even in pristine and well-protected areas, that occurred especially by the end of the 1980s. Why did this unexpected disaster occur? Climate change and pathogens are to blame. This mass extinction is our fault. We, humans, became a population bomb, a term coined by the famous Stanford scientist, Paul R. Ehrlich.

Throughout my life, I have been a witness of frog abundance—but also of the declines and possible extinctions. Jambatos were so abundant at some sites that it was difficult not to step on them; they would walk during rains in the roadsides, even in disturbed habitats. Jambato is a Quechua name that means to cry in the rain. Given their profusion, they were the perfect animal on which to conduct experimental studies. In 1979, I conducted my first serious study (for a high school graduate thesis) of its thermal optimum and ability to resist low and high temperatures. I froze them in the refrigerator to see if they would survive. They did. I also put them directly in boiling water. Imagine the outcome! But, I also did interesting ethological observations and took my first photograph of a frog. I wrote in my high school thesis, This frog seems to be very aggressive… . In the photo, it is observed that five of these are attacking one of the same species, but the latter differs from them in the color of the belly. I naively thought that the smaller ones were trying to kill the larger frog. Although I was so happy to have photographically documented this unique behavior, I realized later that they were trying to mate; the frog being attacked was a female and the five others were males. I would not even imagine that I would end up doing my doctoral dissertation studying the morphology and evolution of Atelopus frogs and later working, desperately, for their conservation.

In 1865, similar behavioral observations were reported by the well-known Spaniard amphibian biologist Marcos Jiménez de la Espada. Espada was the first to publish ample osteological data and natural history observations of amphibians occurring in Ecuador. It has been highly motivating to read his meticulous writings. For example, Espada (1875) gives an account (my English translation) of some aspects of the natural history of the once abundant Atelopus ignescens:

We watched them by the thousands near swampy terrains during the months of November, December, and January in the grassy and humid meadows, near the streams, ponds, or lagoons. On the shores of the mentioned La Mica, in the Antisana, beginning in 1865, I surprised them at the time of their love and when the males look for the females to help them spawn or fertilize their eggs. They chased them through the swamps near water with activity and insistence, and so blind that, struggling to get them, when they reached them, they rolled in balls, scrambled with each other. I confess with regret that I then had little objection to what was offered me to more careful observation, contenting myself with collecting and storing; for now, I have to reduce to mere conjectures what I could have recorded as a true fact… . We still have six couples in our collection, tenaciously embracing and just as I surprised them on the act… . Among the loose females there are several that still have very deep traces of the male embrace.

What Espada and I observed is also treated in a paper published in January 2022 in the journal Animal Behaviour. The young Colombian biologist Alberto Rueda and his colleagues detail similar observations known as mating balls as part of mate guarding behavior in harlequin frogs, Atelopus. Males may remain up to three months strongly embracing the female, whereas unmated males try to remove amplectant males from a female’s dorsum or several males engage in physical combat to amplect a single female.

The end of the 1980s and especially the 1990s were a time of tragedy for frogs in Ecuador and in many parts of the planet. Many species became so rare that it seemed the end of the world for amphibians. I had in my hands, and photographed some, the last individuals of more than a dozen species that have not been seen since that time. That is the case for many species of Atelopus—or of an entire genus, such as the aquatic frogs Telmatobius, unseen in Ecuador since 1994. During the 1980s, I witnessed the collapse of the Jambato populations as well. In March 1983, I photographed what would be the last individual recorded in Quito, in the Chillogallo neighborhood, now fully urbanized. In May 1985, my parents and I observed thousands of road-killed Jambatos near Chimborazo; they were smashed while moving toward their breeding sites. In November 1987, Giovanni Onore and I collected some dead (for unknown reasons) animals 20 km east of Latacunga. However, I did not worry much at that time; they were so abundant that no one would think that they would disappear completely in 1988.

The surprising and sudden declines of frogs were a powerful reason why I had to move from taxonomy to conservation biology. In the 1990s, I began to build a Noah’s Ark for frogs, which in a couple of decades has evolved into the Arca de los Sapos program, now being carried out at Centro Jambatu for Amphibian Research and Conservation. Remember the place (and frogs) I mentioned at the beginning of this essay? Yes, it is Centro Jambatu. Let’s connect a few of those dots. At the center, the Cuicos and Gualatacos live freely in the garden. The first of these species has always been common, and the second is part of a reintroduction program. In contrast, the Jambatos are in an outdoor enclosure where we conduct assessment trials before attempting reintroductions. The calls of the three other species are sounds played in a touch-sensitive screen, where their photos are depicted as part of exhibits, in an effort to educate people about the familiar frogs that used to live in Quito.

Returning to the Jambato, its story has a hopeful outcome. A schoolboy found a relictual population of Jambatos in 2016, in a remote location in Provincia Cotopaxi; a year later we managed to breed them under lab conditions, and now we are developing assisted reproductive technologies to store sperm and breed them to keep genetically viable populations. This is a unique opportunity to revive a beloved and emblematic species. Meanwhile, a thought for the future is recurrent in my dreams: Our center garden having six species of frogs living freely and announcing the coming of the rains, and millions of Jambatos wandering again in all the green areas of Quito, Latacunga, Ambato, paramos, and inter-Andean valleys, so we will have to walk carefully not to step on them.