Thursday 7 December 2023

Río Bigal Biological Reserve - Pristine Foothill Forest In Eastern Ecuador

"What has been your favourite country that you have visited?" 

People often ask me various iterations of this question when they hear about the traveling that Laura and I have been fortunate to have done. Sometimes I say Colombia, sometimes I say Peru, but usually I don't name a country at all. I tell them that my favourite place to explore is anywhere along the eastern slope of the Andes in South America. This may be one of the rainiest regions in the world, but it's also one of the most biodiverse places on our planet. 

As one goes lower in elevation, the Amazon basin has a greater influence on the species diversity, while as one climbs higher in elevation, the species composition changes dramatically until reaching the páramo above 4000 m in elevation with its highly specialized plants and animals. The sweet spot, in my opinion, seems to be between ~700 and ~1300 m in elevation. A dazzling array of Amazonian species make it up to this elevation, while a wide variety of Andean species also thrive. The temperatures are very comfortable, night-hiking is always productive, the mothing is some of the best in the world, and the birding potential is just sky-high. And I haven't even mentioned the butterflies, or the frogs, or the snakes....

Amber Phantom (Haetera piera) - Reserva Biológica del Río Bigal, Orellana, Ecuador

Accessing high-quality forest in the lower eastern slopes of the Andes or further east into Amazonia is not always easy to achieve, without spending thousands of dollars at an expensive ecolodge. Visitors always have to be accompanied by a local guide at these lodges. This means that they have a good chance at coming across many of the specialty animals, but it also means that it is impossible to explore the forest on their own, at their own pace. 

Río Bigal Biological Reserve has been on my radar for quite some time. This gorgeous reserve is the passion project of Thierry Garcia, a Frenchman who has lived in Ecuador since the late 1990s. He started Río Bigal in the years since, his goal being to protect pristine forest in the buffer zone next to Parque Nacional Sumaco-Napo-Galeras. Over the years a simple but comfortable field station has been built, an extensive trail system has been established, and additional lands have been purchased. The reserve ranges in elevation from ~400m to ~1050m, with most of the exploring done between ~850 and ~1050m. 

Reserva Biológica del Río Bigal, Orellana, Ecuador

The visitors at Río Bigal have included researchers, students on university field courses, volunteers, and independent travellers like myself. The cost to stay at the field station is extremely affordable with good quality food and free use of the trail system. For me, the big draw was a chance to explore pristine foothill forest at a reasonable price without having to go with a guide. Don't get me wrong - I have nothing against using guides (heck, I work as one myself!), and I have hired them on numerous occasions. But there is nothing I enjoy more than being able to explore a diverse forest on my own, at my own pace. I find it extremely satisfying and fulfilling to figure things out in the forest on my own. My knowledge of bird vocalizations increases much quicker this way, as opposed to being with someone who is pointing things out. And I often have many of my craziest wildlife experiences when I am on my own, trying to be as quiet as possible. Finally, I had just finished a busy tour and I was really looking forward to solitary time in the forest without any socializing. 

It just so happened that Thierry was traveling from Quito to Río Bigal on November 2 and so I took a taxi over to his house early in the morning. Also along for the ride was Natalia, who would be working at the field station during my stay and cooking all of the meals. The drive was fairly non-eventful and we made good time, though we had to stop for a couple of minutes to gawk at Volcán Antisana, completely unobscured by clouds against a brilliant blue sky. 

Volcán Antisana

We made it to Loreto in the lowlands by noon and, after a quick lunch at a local restaurant, we loaded up our gear into the back of an old Toyota truck that would transport us to the reserve. 

Forty-five minutes later we had reached the end of the "good" road, and so I hopped out and began walking to the reserve, around 3 kilometres further. The others continued in the truck, which was capable of driving along the rough track, but I was happy to walk the entrance road. It was a good thing that I did, since I immediately found a grayish seedeater with thin wing bars and a heavy yellow bill. Could it be my first Slate-colored Seedeater?

Slate-colored Seedeater - Reserva Biológica del Río Bigal, Orellana, Ecuador

The Slate-colored Seedeater is a scarce species that is often misidentified. In Colombia, for example, there are thousands of observations across the country on eBird, yet barely a dozen come with photos or recordings. Gray Seedeaters looks very similar and are more common in disturbed habitats; they are the likely culprit for most of the misidentifications. Being aware of the identification pitfalls, I hadn't confidently observed a Slate-colored Seedeater before, but always kept an eye out, especially when I was birding areas with lots of bamboo. 

Here in eastern Ecuador, Gray Seedeater isn't a possibility and besides, this bird showed all the field marks of a Slate-colored Seedeater. I was pretty thrilled, even though the views were a bit distant.

Slate-colored Seedeater - Reserva Biológica del Río Bigal, Orellana, Ecuador

Though the temperatures were quite warm due to the midday hour and the sunny skies, the birding remained very productive along the walk. It was great to encounter so many of these familiar species again. 

Crested Oropendola - Reserva Biológica del Río Bigal, Orellana, Ecuador

Magpie Tanager - Reserva Biológica del Río Bigal, Orellana, Ecuador

Dorantes Longtail (Thorybes dorantes) - Reserva Biológica del Río Bigal, Orellana, Ecuador

Lysacris sp. - Reserva Biológica del Río Bigal, Orellana, Ecuador

I noticed a distant raptor on a snag and took some photos in an attempt to identify it (I had left my scope back in Canada to save weight on the trip). I was pretty surprised to see that the photos revealed an Orange-breasted Falcon. This rare falcon has a reasonable stronghold along the east slope of the Andes in Ecuador. 

Orange-breasted Falcon - Reserva Biológica del Río Bigal, Orellana, Ecuador

Olive-sided Flycatchers winter along the east slope of the Andes and I quickly tallied at least three on the walk in. Along with Canada Warbler, this was the most common of the wintering species that I noted at Río Bigal. 

Olive-sided Flycatcher - Reserva Biológica del Río Bigal, Orellana, Ecuador

I entered the first patch of secondary forest as I approached the station. Some high pitched calls grabbed my attention and I soon realized that the sounds most likely came from tamarins. A few seconds later and I was watching the group of them as they quickly moved through the trees. 

Black-mantled Tamarin (Saguinus nigricollis) - Reserva Biológica del Río Bigal, Orellana, Ecuador

Thierry and Natalia were waiting for me at the field station along with Jeiber, who is employed at Río Bigal as a forest ranger and general handyman. Thierry showed me to my cabin - a nice surprise since I was under the impression that I would be stationed in a tent on the second floor of the field station. However, in recent years, several cabins have been built on the property. My cabin was simple but with everything I needed, including a large overhang with comfortable chairs for waiting out rainstorms, and 24-hour electricity. A private composting toilet was nearby. Cold showers, meanwhile, were available at the main field station, a two-minute walk from my cabin. 

Cabin at Reserva Biológica del Río Bigal, Orellana, Ecuador

Composting toilet - Reserva Biológica del Río Bigal, Orellana, Ecuador

Río Bigal is truly an ecolodge. All of the water is collected on site, and large storage tanks hold the water used by the showers. All of the garbage is packed out. Some fruits are grown on site, but the rest of the fruit is brought in. There is no internet and Thierry wants to keep it that way, as it allows one to truly disconnect, and reconnect with nature. It is a perfect sanctuary in the middle of a beautiful forest. 

View from inside the field station - Reserva Biológica del Río Bigal, Orellana, Ecuador

Once I was settled in, I spent the remaining daylight hours birding around the station clearing. I find that small clearings like this in the middle of mature forest can be excellent birding sites. Not only is the visibility all the way to the canopy very good, but mixed flocks often linger at edge habitats. My late afternoon stakeout was very productive, the highlight being the second record of Pink-throated Becard for the reserve. This is an example of a lowland Amazonian species that will sometimes make it up to the elevation of Río Bigal. 

Pink-throated Becard - Reserva Biológica del Río Bigal, Orellana, Ecuador

Gray-tailed Piha is a scarce foothill species that seems to have a healthy population at Río Bigal. I heard my first individual singing away. Annoyingly, it would call every five minutes or so, a large enough time gap that I couldn't manage a good recording, nor could I triangulate its location. Luckily, I would have further opportunities to see this species in the coming days. Other highlights from around the station clearing included Variegated Bristle-Tyrant, Grayish Mourner, flyover Military Macaws and a nice selection of tanagers. The last bird that I observed before dark was a Green Manakin - my first - in the bushes in front of my cabin! And then, once darkness hit, the strange calls of a Nocturnal Curassow reached the station from somewhere deep in the forest. 

In the tropics, the fun only continues once the sun goes down, especially if one is interested in herps, arachnids, insects, owls, certain mammals, and many other taxa. As it was getting dark I strung up the moth sheet in front of my cabin and turned on the light, hoping for a good haul of insects. Though I was very eager to see what curiosities would appear, I also wanted to prioritize night-hiking. Even though moths and insects began appearing immediately, I only took a few photos before meeting up with Jeiber and Natalia for our short night hike. This was just a small taste of what was to come later in the evening, and I knew it would be good since the moths began streaming in to the sheet as I walked away to meet with the others. 

Hositea bicincta - Reserva Biológica del Río Bigal, Orellana, Ecuador

Feigeria buteo - Reserva Biológica del Río Bigal, Orellana, Ecuador

Unidentified flower weevil (Baridinae) - Reserva Biológica del Río Bigal, Orellana, Ecuador

Nyceryx tacita - Reserva Biológica del Río Bigal, Orellana, Ecuador

Pronola magniplaga - Reserva Biológica del Río Bigal, Orellana, Ecuador




Druceiella sp. - Reserva Biológica del Río Bigal, Orellana, Ecuador

Colla amoena - Reserva Biológica del Río Bigal, Orellana, Ecuador

Prisopus sp. - Reserva Biológica del Río Bigal, Orellana, Ecuador


Though superficially resembling a moth, this is a species in the family Hedylidae which are currently classified as butterflies. 

Macrosoma bahiata - Reserva Biológica del Río Bigal, Orellana, Ecuador

Ramosulus sp. - Reserva Biológica del Río Bigal, Orellana, Ecuador

Eumorpha phorbas - Reserva Biológica del Río Bigal, Orellana, Ecuador

Our night hike could not have started any better. We hadn't even left the station clearing to began walking down the Palmas trail when Jeiber spotted this large adult Common Lancehead, also known as a Fer-de-Lance. A gorgeous specimen. This is a common species in much of the Amazon basin, and one of the most frequently encountered snakes at Río Bigal. 

Common Lancehead (Bothrops atrox) - Reserva Biológica del Río Bigal, Orellana, Ecuador

The Common Lancehead was the only snake of the night, but to be fair we only stayed out for 1.5 hours or so. I still had a moth sheet to investigate, as well as an early wake-up scheduled in the morning.  That's the problem with being interested in everything when in a beautiful tropical forest. There just simply isn't enough time to explore!

The arachnid diversity on our walk was quite good; I was particularly enamoured with the nice variety of harvestmen. Below are a few standouts. 

Phareicranaus gracilis - Reserva Biológica del Río Bigal, Orellana, Ecuador

Though superficially resembling spiders, harvestmen (order Opiliones) are actually not that closely related to them. Their taxonomic position is disputed, but their closest relatives may be either the mites, or the scorpions and pseudoscorpions. Harvestmen can be distinguished from spiders by their single set of eyes and their fused body segments. While spiders are pure predators, many harvestmen are omnivorous and some are scavengers.

Phareicranaus sp. - Reserva Biológica del Río Bigal, Orellana, Ecuador

We spotted several tarantulas including this Yellow-banded Pinktoe Tarantula. 

Yellow-banded Pinktoe Tarantula (Avicularia juruensis) - Reserva Biológica del Río Bigal, Orellana, Ecuador

Below are a few of the other spiders that I photographed on our night-walk. 

Unidentified wolf spider - Reserva Biológica del Río Bigal, Orellana, Ecuador

Ecuadorian Brown Velvet Tarantula (Megaphobema velvetosoma) - Reserva Biológica del Río Bigal, Orellana, Ecuador

Enoploctenus sp. - Reserva Biológica del Río Bigal, Orellana, Ecuador

Tiger beetles (Cicindelinae) are some of my favourite insects back home in Canada. Several different types could be readily found at Río Bigal, including this widespread Amazonian species, Odontocheila cayennensis

Odontocheila cayennensis - Reserva Biológica del Río Bigal, Orellana, Ecuador

Our path meandered down a hillside until it converged with a crystal-clear creek. Herp diversity improved along the edges of the watercourse and we quickly found a few neat lizards. First up is a type of woodlizard, possibly Enyalioides laticeps, that Jeiber spotted below eye-level. 

Broad-headed Woodlizard (Enyalioides laticeps) - Reserva Biológica del Río Bigal, Orellana, Ecuador

My contribution was this Common Forest Anole (Anolis trachyderma) which was resting on a leaf. 

Common Forest Anole (Anolis trachyderma) - Reserva Biológica del Río Bigal, Orellana, Ecuador

Frog diversity wasn't particularly high on this walk; most individuals appeared to be the same species of rain frog called Pristimantis lanthanites

Metallic Robber Frog (Pristimantis lanthanides) - Reserva Biológica del Río Bigal, Orellana, Ecuador

Metallic Robber Frog (Pristimantis lanthanites) - Reserva Biológica del Río Bigal, Orellana, Ecuador 

We came across this unlucky moth which has been infected with an Akanthomyces fungus. After killing it, the fungus uses the unfortunate insect as a substrate for growing large spikes, out of which it releases spores which will infect other insects to perpetuate the cycle.

Akanthomyces sp. - Reserva Biológica del Río Bigal, Orellana, Ecuador

My headlight beam caught the fluorescent yellows and purples of a Green-backed Trogon which was sound asleep in the understory. 

Green-backed Trogon - Reserva Biológica del Río Bigal, Orellana, Ecuador

I occasionally spot roosting butterflies at night, such as this Oleria ilerdina which is one of hundreds of species of clearwing butterflies which can be found on the east slope of the Andes. 

Oleria ilerdina - Reserva Biológica del Río Bigal, Orellana, Ecuador

Once we finished our walk I immediately made my way over to the sheet to see what moths had arrived to the party. And it was rocking! Hundreds of moths and other insects were taking up nearly every bit of real estate on the sheet, with others spilling onto the nearby limbs and leaves of surrounding trees. It was overwhelming! I could have easily stayed out until the wee hours of the morning, but I forced myself to only spend an hour or so at the sheet, in recognition of the next day's early start time. 

I won't add commentary for each photo as this post is getting long enough. Below are some of the highlights from the mothing session. I'll include a few interesting "non-moths" at the end. 

Herbita amicaria - Reserva Biológica del Río Bigal, Orellana, Ecuador

Dalcerides sp. - Reserva Biológica del Río Bigal, Orellana, Ecuador

Sosxetra grata - Reserva Biológica del Río Bigal, Orellana, Ecuador

Lissocentra hydatodes - Reserva Biológica del Río Bigal, Orellana, Ecuador

Prenesta rubrocinctalis - Reserva Biológica del Río Bigal, Orellana, Ecuador

Cosmosoma sp. - Reserva Biológica del Río Bigal, Orellana, Ecuador

Syssphinx molina - Reserva Biológica del Río Bigal, Orellana, Ecuador

Prepiella aurea - Reserva Biológica del Río Bigal, Orellana, Ecuador

Phostria varialis - Reserva Biológica del Río Bigal, Orellana, Ecuador

Amaxia sp. - Reserva Biológica del Río Bigal, Orellana, Ecuador

Cathydata batina - Reserva Biológica del Río Bigal, Orellana, Ecuador

Eois russearia - Reserva Biológica del Río Bigal, Orellana, Ecuador

Hymenomima camerata - Reserva Biológica del Río Bigal, Orellana, Ecuador

Phostria sp. - Reserva Biológica del Río Bigal, Orellana, Ecuador

Condica mimica - Reserva Biológica del Río Bigal, Orellana, Ecuador

Rosema thalassina - Reserva Biológica del Río Bigal, Orellana, Ecuador

Mania lunus - Reserva Biológica del Río Bigal, Orellana, Ecuador

Hyperandra diminuta - Reserva Biológica del Río Bigal, Orellana, Ecuador

Amaxia pandama - Reserva Biológica del Río Bigal, Orellana, Ecuador

Unidentified (tribe Hemileucini) - Reserva Biológica del Río Bigal, Orellana, Ecuador

Theages xanthura - Reserva Biológica del Río Bigal, Orellana, Ecuador

Melese nebulosa - Reserva Biológica del Río Bigal, Orellana, Ecuador

Leucula festiva - Reserva Biológica del Río Bigal, Orellana, Ecuador

Semaeopus orbistigma - Reserva Biológica del Río Bigal, Orellana, Ecuador

Eucereon sp. - Reserva Biológica del Río Bigal, Orellana, Ecuador

Coenipeta polynoe - Reserva Biológica del Río Bigal, Orellana, Ecuador

Unidentified concealer moth (Oecophoridae) - Reserva Biológica del Río Bigal, Orellana, Ecuador

Oospila ruptimacula - Reserva Biológica del Río Bigal, Orellana, Ecuador

Idalus herois - Reserva Biológica del Río Bigal, Orellana, Ecuador

Rosema maximepuncta - Reserva Biológica del Río Bigal, Orellana, Ecuador

Unidentified moth - Reserva Biológica del Río Bigal, Orellana, Ecuador

Rejectaria niciasalis - Reserva Biológica del Río Bigal, Orellana, Ecuador

Disphragis tharis - Reserva Biológica del Río Bigal, Orellana, Ecuador

Desmoloma modesta - Reserva Biológica del Río Bigal, Orellana, Ecuador

Dyspteris gigantea - Reserva Biológica del Río Bigal, Orellana, Ecuador

Sericoptera mahometaria - Reserva Biológica del Río Bigal, Orellana, Ecuador

Tyrissa perstrigata - Reserva Biológica del Río Bigal, Orellana, Ecuador

Triommatodes sp. - Reserva Biológica del Río Bigal, Orellana, Ecuador

Ernassa sanguinolenta - Reserva Biológica del Río Bigal, Orellana, Ecuador

Syngamilyta nympha - Reserva Biológica del Río Bigal, Orellana, Ecuador

And below are some of the other insects that may their way to the sheet. 

Chloronia sp. - Reserva Biológica del Río Bigal, Orellana, Ecuador

Cyclocephala kuntzeniana - Reserva Biológica del Río Bigal, Orellana, Ecuador

This massive fulgorid planthopper was one of the most impressive ones I've ever seen!

Phrictus hoffmannsi - Reserva Biológica del Río Bigal, Orellana, Ecuador

Ceraiaella triannulata - Reserva Biológica del Río Bigal, Orellana, Ecuador

This long-horned beetle was one of the widest insects to land on the sheet, with its antennae reaching further across than the largest silkmoth. 

Lochmaeocles callidryas - Reserva Biológica del Río Bigal, Orellana, Ecuador

Doradoblatta coppenamensis - Reserva Biológica del Río Bigal, Orellana, Ecuador