The following is a guest post by Evan Twomey, a frog specialist who has been coming to Tarapoto for more years than anyone cares to remember. Twomey is also the reigning International Lomo Saltado Champion. You can read more about poison frogs at Evan’s website, dendrobates.org.
Tarapoto is a popular destination for froggers, and rightly so — roughly 100 species of frogs can be found in the mountains and lowland forests just to the north of the city.
I could provide a list of species easily encountered around Tarapoto, but that is kind of boring. After all, those will be the species easily found in field guides and no one will think you’re special if you find one. Here is an alternative list, pretty useless, but definitely more interesting: The Top 11 Frogs You Aren’t Going to Find on Your Trip to Tarapoto.
The Top 11 Frogs You Aren’t Going to Find on Your Trip to Tarapoto.
11. Hyloxalus azureiventris — Sky-Blue Poison Frog
This small, brightly colored poison frog was named after its brilliant blue belly. Strangely, this species is actually quite common in the mountains near Tarapoto, but it leads such a secretive lifestyle that it is practically never seen. These frogs tend to dwell at the bottoms of large rock piles, inside small caves, underneath treefalls… basically, anywhere impossible to access. During several months in 2004-2005, I was working in a site where this species appeared to be common (tadpoles could be found all over the place). After 7 months of day-in, day-out fieldwork, only a single adult was found, and even this required a headfirst crawl into a pile of rocks.
10. Ameerega yoshina — Evil-Spirited Poison Frog
In 2006, my colleague Jason Brown and I discovered this striking red frog from an isolated mountain range near the town of Contamana. In 2007, another population of this species was found just west of Tarapoto, which was surprising given that this was a well-studied area and it had never been found there before. In both sites, frogs appeared to be abundant — their piercing shrill-call cannot be missed — but actually finding the frogs proved to be nearly impossible. Not only were the frogs mostly calling from underneath rocks and logs, but the slightest movement toward any of the calling males abruptly stopped them calling. After hours and days of being haunted by their calls, we decided the Panoan word Yoshin (meaning ‘devil or evil spirit’) would be an appropriate name to bestow upon this new species.
9. Agalychnis hulli — Hull’s Monkey Frog
Until recently, this frog was only known from a handful of sites near the Peru-Ecuador border. In 2005, a herpetologist stumbled across a thriving population of this species in a small pond along the Tarapoto-Yurimaguas road, over 200 miles south from where the distribution of this species was thought to end. An act of God (the road-paving project) destroyed this pond in 2008, and the species has never again been found in the vicinity of Tarapoto.
8. Ceratophrys cornuta — Amazon Horned Frog
This species is widely distributed throughout the Amazon but rarely found due to its relentless inactivity and tendency for burying everything but its mouth in the mud. During the rainy season, when the mud becomes a little too wet for comfort, the species will emerge and, having nothing better to do, reproduce for a few days a year. If you’re lucky, you can find one then. But I doubt it.
7. Ranitomeya benedicta — Blessed Poison Frog
This recently discovered poison frog has the distinction of being known from one of the worst towns in Peru, a village known as Shucushyacu. Aside from the swarms of mosquitoes that infest the area, the only hotel in town is full of rats. Just ask my friend Mark, who fell asleep while eating crackers in bed only to wake up with two rats on his chest eating the crumbs. And most of the rooms have large holes in the roof (which is actually a good thing if you like astronomy). Even if you do decide to visit Shucushyacu, you won’t see this thing — it is rare, and if you do happen to see it, you won’t catch it — it is one of the fastest frogs I’ve ever seen.
6. Atelopus pulcher — Harlequin Toad
About 20 years ago, this would be an easy frog to find. Sadly, due to a fungal disease known as chytridiomycosis, nearly all the species of Atelopus (around 149 species) are threatened with extinction. This species used to be very common in Ahuashiyacu waterfalls in the mid-90s, but does not occur there anymore. All the juane wrappers that appear in this site every year around San Juan probably don’t help either.
5. Hemiphractus scutatus — Spix’s Horned Frog
This species employs the sit-and-wait hunting style, a style elegant in its simplicity and certainly among the least demanding of the hunting methods currently used by frogs. Among the features desirable in a sit-and-wait hunter include a large mouth, tiny body, and a degree of patience rivaled only by baseball fans. This species is considered a “marsupial frog”, which means that females incubate eggs on their backs. These guys skip the tadpole stage and hatch from their egg as tiny frogs.
4. Phyllomedusa bicolor — Giant Monkey Frog
This is definitely one of the most impressive treefrogs around. It’s also a species you aren’t likely to find on your trip to Tarapoto, unless you find a nice lowland swamp and happen to be there at the right time of year. One cool thing about this frog is that it has wildly bioactive skin secretions that are used by Matses Indians to improve endurance and hunting ability. Just catch a frog, slowly roast it over a fire, collect the skin secretions, and introduce them into your bloodstream (applying the skin secretions on self-inflicted burns is apparently the preferred method). After a couple hours of explosive diarrhea and vomiting, you’ll be rewarded with enhanced endurance and sharpened senses, not to mention major jungle cred.
3. Cochranella resplendens — Resplendent Cochran Frog
Before 2004, this frog was not thought to occur anywhere near Tarapoto, being known only from a couple of sites in Colombia and Ecuador. Then, one day, I saw a tiny green frog jumping around on my boot when I was in the forest. Turns out it was this guy, representing a new country record and a few-hundred mile range extension for the species. That remains the only record of this species in Peru – it hasn’t been found again since.
2. Cruziohyla craspedopus — Fringed Leaf Frog
Most people that study frogs in South America agree — this species is the Holy Grail. This frog spends almost its entire life in the highest parts of the canopy of pristine rainforest. Once a year they come down to the ground to breed in things like hollow tree stumps or small pools on the forest floor.
1. Allophryne resplendens — Resplendent Hill Frog
All the frogs on this list so far I would consider “extremely difficult to find”. This species is probably better described as “impossible to find”. There have been a grand total of four individuals of this species encountered, anywhere, ever. Two of the specimens made it into museums, which is good, because museum specimens are needed for any species to be formally described (this species was described in 2012). The other two specimens weren’t so lucky — one was simply lost, while the other specimen decomposed when the seal broke on the storage jar and all the alcohol evaporated away.
All photos © Evan Twomey except for:
Ceratophrys cornuta — Maarten Sepp, Wikimedia Commons