Expedition Reports: Peruvian Upper Amazon

Carlos Romero

Expedition Reports: Peruvian Upper Amazon

Carlos Romero

The first full day of our expedition on the Upper Amazon in Peru was filled with adventure, excitement, and many new firsts for the enthusiast group of guests we have aboard the Delfin II. We started early in the morning with a skiff ride along one of the main tributaries of the Amazon River, the Marañon River. Our home away from home this week, the Delfin II, was “tied up” since last night after a short navigation of approximately seven miles from Nauta town, close to a place known locally as “Casual.” We explored the area at a low speed with our fleet of skiffs looking for wildlife. The three skiffs that were outside had different sightings. We were very successful for in this pre-breakfast outing we spotted several bird species including Chestnut-bellied seedeaters, Oriole blackbirds, Boat-billed flycatchers, and Greater anis. For me on a personal note this outing was great for I spotted a new bird species for my life list, a White-headed Marsh Tyrant (Arundinicola leucocephala), which is considered an uncommon sighting along rivers in northeastern Amazonia. This boldly-patterned small flycatcher was seen very briefly perching over the river-edge vegetation. One skiff, on the other hand, managed to see three species of monkeys in one hour in the first outing! How cool is that? A Pygmy Marmoset and two troops of Black-mantle Tamarins and Squirrel Monkeys were spotted.

After breakfast we went out once again but this time to explore Casual by walking on “Terra firme,” a term used to describe areas that never get flooded. We had two choices: a long walk and shorter version. On both options we had the joy to spot several plant species and listen to our expert Delfin II naturalists explaining some fascinating aspects of the ecology of the rain forest of the Neotropics. Several species of frogs and lizards were seen as well including one of the most beautiful and spectacularly colored frog species found in the Amazon, the Red-backed Poison Frog (Ranitomeya reticulatus). These colorful frogs, also known as Poison Dart frogs, are not only beautiful but have a remarkable natural history as well. They have alkaloid skin secretions that give them their common name. Traditionally many indigenous people use these powerful toxins all over the Amazon region to coat hunting darts and arrows. The toxicity of the secretions is determined by the frogs´ diet that consists mainly on some species of ants that they prefer to eat. The chosen ants contain high concentrations of formic acid. In captive conditions when these frogs are fed with other kind of insects they lose the toxicity. Another species spotted worthy to be mentioned is the Crested Forest Toad (Bufo margaritifer Complex). This frog is a master in camouflage. It looks like a leaf. The “complex” designation refers to the complicated taxonomy in these animals.

The highlight of the morning was after all the spotting of an Amazon forest dragon (Enyaloides laticeps). According to the book “Reptiles and Amphibians of the Amazon, an Ecotourist’s Guide” by R.D. Bartlett and Patricia Bartlett, there are seven species in the Lizards’ Genus Enyaloides. These pretty lizards are all big-headed with a pronounced vertebral crest. They are diurnal and mostly seen clinging to the trunks of small trees mainly in primary forests. Amazon forest dragons attain a total length at adulthood of approximately one foot. They are oviparous, meaning that they lay eggs. The specimen we saw today was a young female, there is a marked sexual dimorphism in this species for the males are larger and have orange bellies. I was lucky enough to see the dragon so well that after a quick close inspection I noticed that the belly in the specimen we saw was tan suffused with a pink blush confirming it was a female! Another first time observation for me!

The long walkers reached a giant strangle fig that was used for group pictures. The tree has many long and strong lianas. Some of us had the thrill to use a liana to swing some feet above the ground. After these activities, once onboard, we had a couple of introductory talks, one on the Amazon and one on the Reserve. While having lunch we had the joy to observe many pink river dolphins from our dining room’s ample windows.

In the afternoon, we went to explore the Pucate and Yanayacu Rivers. As this area is an important point to go inside the Pacaya Samiria Reserve, there is a Ranger Station at the entrance. We spent the whole late afternoon riding the skiffs with great weather, it was very calm, there were lots of birds flying and calling. We spotted a couple of monkey troops and many bird species including parrots and parakeets. Once aboard the Delfin II naturalists had an informal yet entertaining introduction on how they became guides, their families, places they were born in the area, etc. that helped our visitors see their intimate side.

What a day! At the moment I am writing these paragraphs I do feel in fact a little tired but with the enormous satisfaction of having had a wonderful and memorable day.

- Carlos Romero; Expedition Leader, Lindblad Expeditions