Tuesday 28 April 2020

The Osa Peninsula - Part 1


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The Osa Peninsula is the best example of lowland Pacific rainforest in Costa Rica. Jutting out into the ocean just north of the Costa Rica / Panama border, the Osa Peninsula maintains much of its original forest cover, especially in several protected areas: Corcovado National Park and the Golfo Dulce Forest Reserve. More than half of Costa Rica's species can be found in these productive lowland forests, including populations of Jaguar and Baird's Tapir.

Bolita Rainforest Hostel, Puntarenas, Costa Rica

The Osa Peninsula had long been a destination that drew my attention, and as a fledgling birder it was a place that I knew I had to visit some day.  I had romanticized the idea of the Osa Peninsula as a remote wilderness with untold varieties of snakes, frogs, birds, and other creatures finding habitat within the steamy jungles and picturesque sandy beaches, away from any sign of humans.

It turns out the Osa Peninsula is very easy to access and visit, being a short 4 hour drive from Los Quetzales National Park, and thus a 5.5 hour drive from the airport in San José. I have come to realize that true wilderness is hard to come by in Central America, though I am sure that parts of Corcovado National Park come close. At any rate, driving down the coastal highway and then turning west and following the road into the Osa Peninsula felt almost too easy considering how I had sentimentalized the place in my head all those years ago. But by late afternoon on March 2nd, we found ourselves navigating this route and making our way to the small town of Dos Brazos. Dos Brazos is situated beside the border to Corcovado National Park and is a jumping off point for visiting the primary forests in the interior of the Osa Peninsula.

Scarlet Macaws - Bolita Rainforest Hostel, Puntarenas, Costa Rica

We only stopped a few times along the drive, including once for a pair of Fiery-billed Aracaris. We also made a quick birding stop at the Río Rincón bridge. This popular spot amongst birdwatchers is oft-cited as a location to see Yellow-billed Cotinga, Mangrove Hummingbird, and if you are really lucky, Turquoise Cotinga. We only had 15 minute to spare here but scored a flyover Yellow-billed Cotinga, some Costa Rican Swifts and a pair of Scarlet Macaws (we would quickly appreciate how common Scarlet Macaws are in the Osa!).

Yellow-billed Cotinga - Puente Río Rincon, Puntarenas, Costa Rica

Laura and I had booked a room at the Bolita Hostel, a place quickly becoming famous among naturalists. Bolita is especially popular among vagabond backpacker types who wish to escape the hustle and bustle of the city. The demographics skewed to the early-20s and Laura and I were some of the oldest ones staying there. Bolita is sustainably run, being garbage-free for several years now. Solar panels create electricity which is used for the cell-phone charging station and the LED lights in each of the rooms, and the water is piped in from a nearby spring. Propane tanks fuel the stove and, like everything else at Bolita, need to be carried in on someone's shoulders while they navigate the 40 minute entrance trail uphill through mature tropical forest. The hostel does not provide meals, therefore guests need to carry in all of their own food.

Bolita Rainforest Hostel, Puntarenas, Costa Rica

Bolita appealed to us for a few reasons. One, its location at the edge of the primary forest, with many kilometres of well-marked trails snaking into the surrounding landscape. And two, its price. Laura and I "splurged" on one of the cabinas for 15$ a night per person (dorm rooms are 12$ per person). A friend of mine, Mark Dorriesfield, had visited Bolita on several occasions and raved about it, so we were sold.

Common Basilisk (Basiliscus basiliscus) - Uvita area, Puntarenas, Costa Rica

It was nearly sunset when Laura and I pulled into the parking lot for Bolita Hostel, at the edge of the town of Dos Brazos. We loaded up our packs with our gear and food and hit the trail. I have to admit it was a struggle due to the high temperatures and humidity levels, combined with the weight of our packs. The steep uphill sections did not help either! At least there were a few birds to keep us company and I added some of the bird specialties for the area - Black-hooded Antshrike and Riverside Wren, along with a Marbled Wood-Quail - all heard-only. Eventually we made it to the hostel, met the owner and a few of the other guests, and checked in. A small nearby pond was alive with frogs calling, including this Rosenberg's Gladiator Frog (Boana rosenbergi). A Spectacled Owl was also heard from somewhere in the distance.

Rosenberg's Gladiator Frog (Boana rosenbergi) - Bolita Rainforest Hostel, Puntarenas, Costa Rica

We were pretty exhausted and so after making dinner, we took it easy and called it a night early. We had three nights in total at Bolita and were looking forward to spending the second and third nights in the forest, looking for herps.

Bolita Rainforest Hostel, Puntarenas, Costa Rica

I woke before dawn, excited for the possibilities that lay ahead! Prior to visiting the Osa Peninsula, I had made a list of target "lifers" that I could find here. These included 13 species that are only found on the Pacific slope of Costa Rica and western Panama: Fiery-billed Aracari, White-crested Coquette, Charming Hummingbird, Costa Rica Swift, Golden-naped Woodpecker, Baird's Trogon, Black-hooded Antshrike, Chiriqui Foliage-gleaner, Yellow-billed and Turquoise Cotingas, Orange-collared Manakin, Riverside Wren and Spot-crowned Euphonia. Additionally, two Costa Rican endemics can be found on the Osa Peninsula - Black-cheeked Ant-Tanager and Mangrove Hummingbird. And finally, I had a list of seven more widespread species that would be potential lifers. These included White-tipped Sicklebill, Bronzy Hermit, Rufous-winged Woodpecker, Long-tailed Woodcreeper, Yellow-bellied Tyrannulet, Scarlet-rumped Tanager and Shining Honeycreeper. 

White-nosed Coati - Bolita Rainforest Hostel, Puntarenas, Costa Rica

Our first morning of exploration was a good one. We walked up the Big Banana Trail to Valle Frijol, stopping frequently along the way. Early highlights included Shining Honeycreeper, some singing Black-hooded Antshrikes and Riverside Wrens, and the above White-nosed Coati. Our main target here was the Turquoise Cotinga, a range-restricted species that can be a bit tricky to find. The panoramic vista of the valley alongside the Big Banana Trail made the searching much easier and Laura spotted the first Turquoise Cotinga, perched distantly at the top branches of a super-canopy tree. We counted 5(!) Turquoise Cotingas in total along the trail. All were electric blue males, their plumage much easier to spot at a distance when compared to the drab, brownish females.

Turquoise Cotinga - Bolita Rainforest Hostel, Puntarenas, Costa Rica

We continued along the trail through a stand of trees when familiar crackling and popping sounds reached our ears. Manakins! Around a half-dozen male Orange-collared Manakins were displaying to hidden females. We watched the show with smiles on our faces, since manakins are some of our favourite birds. The Orange-collared Manakins ended up being the most common manakin at Bolita, followed by Red-capped and then Blue-crowned.

Orange-collared Manakin - Bolita Rainforest Hostel, Puntarenas, Costa Rica

The regional specialties kept appearing. Next up were two different Chiriqui Foliage-gleaners, a Bronzy Hermit, several heard-only Baird's Trogons, and a few Black-cheeked Ant-Tanagers! Black-hooded Antshrikes finally moved off the heard-only list and throughout the day we had a good five or six close encounters with them.

Chiriqui Foliage-gleaner - Bolita Rainforest Hostel, Puntarenas, Costa Rica

Black-hooded Antshrike - Bolita Rainforest Hostel, Puntarenas, Costa Rica

Black-hooded Antshrike - Bolita Rainforest Hostel, Puntarenas, Costa Rica

The trail around the Valle Frijol passes through secondary forest and scrubby areas, though with an excellent view of the valley. In addition to the above species we also observed White-whiskered Puffbird, Sulphur-rumped Flycatcher and Chestnut-backed Antbird, all pictured below.

White-whiskered Puffbird - Bolita Rainforest Hostel, Puntarenas, Costa Rica

Sulphur-rumped Flycatcher - Bolita Rainforest Hostel, Puntarenas, Costa Rica

Chestnut-backed Antbird - Bolita Rainforest Hostel, Puntarenas, Costa Rica

A vocal pair of Scarlet Macaws soared over us and landed on a nearby tree. Like many other macaws, Scarlet Macaws form monogamous pairs that will mate for life. Fortunately, Scarlet Macaws are doing quite well in the Osa Peninsula and the population is considered stable.

Scarlet Macaws - Bolita Rainforest Hostel, Puntarenas, Costa Rica

The early morning bird activity was strong but it began to wane slightly as the sun crept higher in the sky. The resulting thermals encouraged different raptors and vultures to take to the air including King Vulture, Gray-headed Kite, White Hawk and Common Black-Hawk. A pretty nice selection.
  
King Vulture - Bolita Rainforest Hostel, Puntarenas, Costa Rica

Reptile activity also markedly increased. We started noticing Middle American Ameivas by the dozen as they skittered off the path.

Middle American Ameiva (Holcosus festivus) - Bolita Rainforest Hostel, Puntarenas, Costa Rica

Middle American Ameiva (Holcosus festivus) - Bolita Rainforest Hostel, Puntarenas, Costa Rica

A serpentine shape grabbed my attention as well, but it shot off the trail impossibly quickly. Luckily, it did not go far and we enjoyed the Salmon-bellied Racer (Mastigodryas melanolomus) through our binoculars. It was certainly not catchable given its location partway down the steep slope! And besides, Mastigodryas are not exactly the most docile snakes; I was happy to keep all of my blood inside of me.

Salmon-bellied Racer (Mastigodryas melanolomus) - Bolita Rainforest Hostel, Puntarenas, Costa Rica

We reentered good quality forest as the Valle Frijol Trail gave way to the Fila Quemada. We welcomed the shade once again, as well as more bird and herp activity.

Orange-chinned Parakeet - Bolita Rainforest Hostel, Puntarenas, Costa Rica

Two more of my target bird species quickly fell. First was a Charming Hummingbird that did not stick around long enough for photos, and second was a Golden-naped Woodpecker tapping on a dead trunk. Woodpeckers are awesome and I was thrilled to see another new species.

Golden-naped Woodpecker - Bolita Rainforest Hostel, Puntarenas, Costa Rica

The good birds just kept on coming! Next up was a Scaly-throated Leaftosser - a totally rad bird with a neat behaviour of habitually tossing aside leaves on the forest floor to reveal morsels underneath. 

Scaly-throated Leaftosser - Bolita Rainforest Hostel, Puntarenas, Costa Rica

A female Red-capped Manakin posed nicely in the understory, as did a pair of Rufous Pihas. Rufous Piha is a species of cotinga that is usually higher in the forest; seeing a pair at eye-level was a real treat.

Red-capped Manakin - Bolita Rainforest Hostel, Puntarenas, Costa Rica

Rufous Piha - Bolita Rainforest Hostel, Puntarenas, Costa Rica

Rufous Piha - Bolita Rainforest Hostel, Puntarenas, Costa Rica

Our luck with Baird's Trogon finally turned at this point. We had heard several individuals already, but every single one had remained hidden. This finally changed and we soaked in the views from only 30 feet away.

Baird's Trogon - Bolita Rainforest Hostel, Puntarenas, Costa Rica

Baird's Trogon is a handsome species; the males show a striking red belly, white underside to the tail, heavy bill and blue eye ring; the females are a little more subtle with a grayish upper body, orange belly and a barred tail, but still exhibiting the large eye-ring.

Baird's Trogon - Bolita Rainforest Hostel, Puntarenas, Costa Rica

Often when Laura and I explore a forest we are focused on different species and we utilize different strategies. I often scan the canopy and subcanopy, or look for movement deep in the understorey with birds on my mind. Laura's gaze often gravitates to the ground and lower branches as she searches diligently for herps and insects. Her technique paid off once again as Laura found two Helmeted Iguanas within a span of 15 minutes!

Helmeted Iguana (Corytophanes cristatus) - Bolita Rainforest Hostel, Puntarenas, Costa Rica

While Helmeted Iguanas can be relatively common in some forests, they are rarely spotted due to their practice of freezing in place when a threat is spotted. Interestingly, unlike most reptiles, Helmeted Iguanas are non-heliothermic. This means that they do not utilize the sun's rays to directly increase its body temperature; instead, they stay in the shadows and maintains a body temperature of around 26 degrees C.

Helmeted Iguana (Corytophanes cristatus) - Bolita Rainforest Hostel, Puntarenas, Costa Rica

The second individual was quite small, with a much-reduced head casque.

Helmeted Iguana (Corytophanes cristatus) - Bolita Rainforest Hostel, Puntarenas, Costa Rica

Helmeted Iguana (Corytophanes cristatus) - Bolita Rainforest Hostel, Puntarenas, Costa Rica

Helmeted Iguana (Corytophanes cristatus) - Bolita Rainforest Hostel, Puntarenas, Costa Rica

Below is a selection of a few other herps that we crossed paths with during our hike.

Brown Forest Skink (Scincella cherriei) - Bolita Rainforest Hostel, Puntarenas, Costa Rica

Craugastor sp. - Bolita Rainforest Hostel, Puntarenas, Costa Rica

Osa Anole (Anolis osa) - Bolita Rainforest Hostel, Puntarenas, Costa Rica

Green-and-black Dart Frog (Dendrobates auratus) - Bolita Rainforest Hostel, Puntarenas, Costa Rica

Osa Anole (Anolis osa) - Bolita Rainforest Hostel, Puntarenas, Costa Rica

This huge moth grabbed our attention when it flushed from a trailside shrub, but fortunately landing a few meters up the trail from us. It is Castniomera atymnius, also known as the Giant Butterfly-Moth. Indeed it does appear rather butterfly like, especially with antennae that appear almost clubbed.

Castniomera atymnius - Bolita Rainforest Hostel, Puntarenas, Costa Rica

At this point we were firmly into late-morning and bird activity was decreasing quickly. Nonetheless we enjoyed a few nice sightings along both the Fila Quemada and a small footpath leading to a viewpoint.

Slaty-tailed Trogon - Bolita Rainforest Hostel, Puntarenas, Costa Rica

Yellow-throated Toucan - Bolita Rainforest Hostel, Puntarenas, Costa Rica

We returned to the Bolita Hostel tired and thirsty but satisfied with a very productive walk! That afternoon we enjoyed a well-earned siesta. 

Jumping spider sp. - Bolita Rainforest Hostel, Puntarenas, Costa Rica

By mid-afternoon we were ready to hit the trails again. This time we chose the Cacique Trail, as my friend Mark Dorriesfield had had success there in the past with White-crested Coquette, one of my few remaining target birds (and the most "important" one).

Our walk was quite enjoyable and our day list climbed past 100 species. Blue-throated Goldentails, a type of hummingbird, were common along this trail and several males had established territories.

Blue-throated Goldentail - Bolita Rainforest Hostel, Puntarenas, Costa Rica

A few Short-billed Pigeons finally posed for my camera as well. It can be a struggle to see and / or photograph pigeon types in the tropics at times.

Short-billed Pigeons - Bolita Rainforest Hostel, Puntarenas, Costa Rica

A Rufous Mourner provided great views, followed by more Black-cheeked Ant-Tanagers. Once again, they managed to escape having their photo taken! One more lifer was in store - a pair of Spot-crowned Euphonias high up in the canopy.

Natural swing - Bolita Rainforest Hostel, Puntarenas, Costa Rica

We returned to the hostel just before sunset and spent the rest of the daylight sitting at the upper terrace at the hostel, watching the tanagers and flycatchers around the clearing. A pair of Shining Honeycreepers flit about while the Gray-capped Flycatchers were building a nest.

Shining Honeycreeper - Bolita Rainforest Hostel, Puntarenas, Costa Rica

Gray-capped Flycatcher - Bolita Rainforest Hostel, Puntarenas, Costa Rica

It had been a highly productive day! That evening we headed out on our first night-hike, finding a few snakes among other highlights. I will detail that, as well as the next day's activities, in my next blog post.

1 comment:

Mary Ann Good (Mom/Grandma) said...

I promise I won't write long missives to every post of yours I read -- and I know the Osa Peninsula is ancient history for you, but I just spent two week-long trips there -- well, at least on the equally biodiverse mainland across the Golfo Dulce where our lodge is reachable only by boat and surrounded by isolated Piedras Blancas NP (my eighth time visiting the area as well as birding on the Osa a few times, especially at Bosque del Rio Tigre, very near to where you stayed). It was a-MAY-zing reading your post, chock-full of avian, herp, and other observations, and I was enormously tickled to notice that I have seen (or in a few cases heard) every single one of them that you mentioned, with the exception of the Spectacled Owl (have seen elsewhere), jumping spider, butterfly-moth, and Brown Forest Skink. I haven't read Part II yet, but I did scan it to see if you did see your big target, White-crested Coquette -- I see that you did! and I've been lucky to see that there as well. My guide and I had knockout views of a sleeping Salmon-bellied Racer curled up on the branch right at our heads as we climbed down into a creekbed to try to find the calling glass frogs. Interesting to hear you say they're not the most docile of snakes, but this sleeping beauty, that we photo'd from a foot away at eye level, certainly was! We also seem always to find a Helmeted Iguana on our night walks there (at our favorite lodge across the gulf), just as you found several. Finally -- sorry for boring you with my stories, but since I was just researching the Anolis osa, it was fascinating to me that you found them also. My guide had told me the one we saw (across the gulf) was the endemic Osa Anole, but since then I've discovered that they are truly restricted to the Osa and that what we saw was the also-endemic (ours to SW Costa Rica and NW Panama) congener, Anolis polylepis. We also saw that identical bright orange dewlap!  Fun fun stuff!!!