Visiting The Legendary Bosque Unchog

Bosque Unchog is a place of great lore in South American birding. The elfin forest above the town of Acomayo along the eastern crest of the Andes in Peru had been unexplored from an ornithological point of view until the mid 1970s. In the early 1970s half-brothers Reyes Rivera and Manuel Villar discovered several species completely unknown to science in the hills above their homes in Acomayo, including the Pardusco and Golden-backed Mountain-Tanager. In 1974, young ornithologist Ted Parker was invited to join the Louisiana State University Museum of Ornithology's Peruvian expedition, and during his trip he spent several days high up in the elfin forest at Quilluacocha, the site where Villar had first discovered the Golden-backed Mountain-Tanager. At the time of Parker's trip, only Villar, Rivera, and Villar's father had ever observed the bird. 

Golden-backed Mountain-Tanager - Bosque Unchog, Huánuco, Peru

Ted Parker is a larger than life figure in South American ornithology due to his impressive field skills - some have said that he was the most skilled birder who had ever explored the Neotropics. Most aspiring Neotropical birders (myself included) see him as a sort of legend. Unfortunately, his untimely death caused by a 1993 plane crash in a remote region of Ecuador prevented him from fulfilling his incredible potential, but in his few years he was instrumental in discovering several new species to science, while also voice-recording many dozens (hundreds?) for the very first time. It is often incorrectly reported that he discovered the Golden-backed Mountain-Tanager and Bay-vented Cotinga - rather, he was the initial ornithologist to observe them, as well as photograph them and record their voices and life histories for the first time. 

Bosque Unchog, Huánuco, Peru

Visiting Bosque Unchog is a little simpler now compared to Parker and Rivera's arduous trek from Acomayo to the ridge back in January of 1975. A gravel road snakes up the steep hillsides to the town of Cochabamba, and eight kilometres further to Bosque Unchog. Until recent years, it was only possible to traverse the final stretch with 4x4 but the road has been recently improved; so much so that a small car can now make the journey!

August 2, 2022

Laura and I set off well before dawn from our AirBnB apartment in Huánuco, expecting a 2.5 hour drive to reach the site. I had braced myself for a hair-raising drive up the mountainside in the dark with our Toyota Corolla. Surprisingly, there were almost no sketchy bits to the road and we arrived at Bosque Unchog shortly after 5:30 AM. The sky was only just beginning to lighten. Laura rested in the car until dawn while I set out with my bluetooth speaker and binoculars, eager to start my eBird checklist with some birds more typically encountered at night. 

I returned 45 minutes later with a heard-only Jameson's Snipe for my efforts (along with far too many Great Thrushes). Laura and I ate breakfast, loaded our packs for the day's hike, and set off down the rough trail passing through bunchgrass meadows laden with bromeliads and orchids, still frosty from the chilly night. 

Bosque Unchog, Huánuco, Peru

Bosque Unchog is home to four species in particular that are high on any visiting birder's wish list. These are the Bay-vented Cotinga, Pardusco, Rufous-browed Hemispingus and of course, the spectacular Golden-backed Mountain-Tanager. While these birds have since been discovered further afield in other remote sections of the eastern Peruvian Andes, Bosque Unchog remains the only easily accessible and reliable location for all four species. 

We had to wait a little while before knocking the first target off the list. As we strolled through the meadows and near to one small Polylepis patch, we added a number of species to our list including several lifers - heard-only Neblina Tapaculos and several attractive Coppery Metaltails. Both are endemic species to Peru, only finding habitat in treeline scrub at the eastern crest of the Andes. The metaltails were surprisingly common during our hike. 

Coppery Metaltail - Bosque Unchog, Huánuco, Peru

We reached the second Polylepis patch and began our descent. We had neared the area where our four main target species are often found. 

Bosque Unchog, Huánuco, Peru

Polylepis forest - Bosque Unchog, Huánuco, Peru

And then it happened. Through a window in the stunted forest, I noticed some movement along a distant hillside. A Golden-backed Mountain-Tanager, in all its glory! Laura and I excitedly watched a pair of them through the gap and, with a stroke of luck, both flew directly towards us and alighted in the trees above our heads. The lighting was poor for photos, but we could easily appreciate the colours (and huge size) of these gorgeous mountain-tanagers. 

It was our lucky day. We ended up seeing several pairs of Golden-backed Mountain-Tanagers between the second and third Polylepis groves. We conservatively estimated six individuals, but there may have been more. Here are some of my favourite photos of them. 

Golden-backed Mountain-Tanager - Bosque Unchog, Huánuco, Peru

Some of the individuals seemed to not care at all about our presence, actively foraging only a few meters from us!

Golden-backed Mountain-Tanager - Bosque Unchog, Huánuco, Peru

Golden-backed Mountain-Tanagers - Bosque Unchog, Huánuco, Peru

Golden-backed Mountain-Tanagers - Bosque Unchog, Huánuco, Peru

Nothing could top that! The fog began to roll in around this time, causing some concern. How would we be able to spot distant cotingas perched on treetops? 

Bosque Unchog, Huánuco, Peru

While the Bay-vented Cotinga was next on our hit list, another cotinga was complicating things. The Red-crested Cotinga is a very cool bird, but it is one that we have found on many previous occasions throughout its large range in the Andes. We were beginning to harbour a little bit of animosity towards the species when we spotted our fourth Red-crested Cotinga with not a Bay-vented in sight. 

Red-crested Cotinga - Bosque Unchog, Huánuco, Peru

Finally, our persistence paid off. I spotted a distant cotinga sporting a brownish chest and belly. It was too far for good photos so the following was all I could manage. It would have been handy to have my scope with us, but I had decided to leave it in the car as it would be a little cumbersome to carry with us all day long. We hoped for closer encounters later in the day, but this would be the only Bay-vented Cotinga that we would see.

Bay-vented Cotinga - Bosque Unchog, Huánuco, Peru

With two out of our four big targets in the bag, the pressure was lessened somewhat. Strangely, we had not encountered any Parduscos even though they are supposedly a common constituent of mixed flocks. The Rufous-browed Hemispingus was also missing. This species is the most difficult of the Big Four and many birders who visit Bosque Unchog miss this species. It does not help that its song is extremely similar to that of the very common Moustached Flowerpiercer. On several occasions I was pretty sure that we were listening to a hemispingus, only to have a flowerpiercer pop out. Interestingly, many birder's checklists list the hemispingus as "heard only"...

Bosque Unchog, Huánuco, Peru

Even during relatively slow periods, we added new birds here and there. Unfortunately, three of the species new to us remained as heard-only, including White-winged and Neblina Tapaculos and Chachapoyas Antpitta. Another lifer for us was the Line-fronted Canastero, a species which is at home in these stunted, bromeliad-rich habitats at the treeline. 

Line-fronted Canastero - Bosque Unchog, Huánuco, Peru

Line-fronted Canastero - Bosque Unchog, Huánuco, Peru

Speaking of bromeliads, it was hard not to marvel at the plant life at this site. I am not in the least a plant expert, but I could imagine that a botanist would be in heaven here.

Begonia hirta - Bosque Unchog, Huánuco, Peru

Telipogon sp. - Bosque Unchog, Huánuco, Peru

Leach Orchid (Stelis sp.) - Bosque Unchog, Huánuco, Peru

Golden Cyrtochilum (Cyrtochilum aureum) - Bosque Unchog, Huánuco, Peru

Puya laccata - Bosque Unchog, Huánuco, Peru

Incan Earring (Brachyotum ledifolium) - Bosque Unchog, Huánuco, Peru

Finally, various chips and zeets in the distance led us down the slippery trail towards our first mixed flock of the day. Mixed in with the bunch were a handful of Parduscos. This unique little bird is not as flashy as a Golden-backed Mountain-Tanager but it is also a member of the tanager family, Thraupidae. 

Pardusco - Bosque Unchog, Huánuco, Peru

The Pardusco was one of several tanagers that were discovered by Rivera and Villar in 1973. At the time of Parker and Rivera's expedition in 1975, it had not yet been formally described, and Parker became the first to extensively study it and document its behaviour. 

Pardusco - Bosque Unchog, Huánuco, Peru

Pardusco - Bosque Unchog, Huánuco, Peru

Quite a few other species formed the mixed flock including White-browed Spinetail, White-chinned Thistletail, Ochraceous-breasted Flycatcher, White-throated Tyrannulet, Citrine Warbler and Blue-backed Conebill. Arguably the most incredibly-plumaged species in the flock was the Yellow-scarfed Tanager. I think that Laura and I both have this Peruvian endemic species as one of our favourite Peruvian birds. 

Yellow-scarfed Tanager - Bosque Unchog, Huánuco, Peru

Anecdotally, it seems that quite a few tanagers found in the elfin forests of the eastern Andes sport flashy yellows on part of their bodies. I wonder if it helps them keep track of each other visually in an environment that is often socked in with fog? Perhaps someone has already looked into this...

Yellow-scarfed Tanager - Bosque Unchog, Huánuco, Peru

For the rest of the day Laura and I had one goal: to spot a Rufous-browed Hemispingus. We tried high and low, spending close to an hour deep in the third Polylepis patch where they are often recorded by visiting birders. On the walk back up we kept an eye and an ear out in all suitable areas. I heard one strong candidate singing (and recorded its song), but with the interference of a nearby creek and a vocalizing hummingbird it is hard to say for sure if a Rufous-browed Hemispingus was involved. 

Bosque Unchog, Huánuco, Peru

Laura and I took our time retracing our steps during the early afternoon. It was tough going as we needed to gain over 400 m in elevation, while hiking in the thin air found over 3500 m. During one break in our travels, I stopped to photograph some Páramo Pipits for the first time. With some patience I was able to approach one quite closely for photos. 

Páramo Pipit - Bosque Unchog, Huánuco, Peru

Páramo Pipit - Bosque Unchog, Huánuco, Peru

Páramo Pipit - Bosque Unchog, Huánuco, Peru

One last-ditch attempt for the hemispingus occurred during the steep ascent through dense forest in Polylepis patch #2, seemingly perfect habitat for our target. Again, we were unsuccessful. 

The rest of the climb was arduous and we needed to take frequent brakes. I'm afraid that I may have killed Laura with the steep ascent...

 Bosque Unchog, Huánuco, Peru

Fortunately, we both made it to the top alive and with our wits mostly about us. The day had been incredible - just us, the birds, the orchids and the incredible mountain scenery. It was truly one of my favourite days spent in Peru thus far!

We made a couple of brief stops on the drive back down to Cochabamba as we were now on the dry portion of the mountain, home to different species than those which reside on the moisture-laden side where we had hiked. One of the birds that I caught up with was the Brown-flanked Tanager, a species endemic to central Peru. And with that, we left the area behind to recuperate at our apartment in Huánuco. What a day...

Brown-flanked Tanager - Cochabamba, Huánuco, Peru