Tuesday, February 4, 2014

Owls, potoos and nightjars of Ecuador (and a tinamou to boot)

I recently returned from a 4-week independent birding trip to Ecuador (buses and hiking lots!) where I saw 656 species of birds without ever making it to the coast, including 19 owl species, 14 species of antpitta (9 on trails and 5 to worms) and many more, for example 70 species each of hummingbirds and tanagers! I hope to prepare some blog posts on the trip and will start, as always, with the night birds.

This trip was basically a transect across northern Ecuador from east to west. We start therefore in the lowlands of the Amazon basin in the area around Yasuní National Park. One of the highlights for me here was getting photos of Spectacled Owl. Spectacled Owl is the largest of the three species in the genus Pulsatrix (some authors split it to give a fourth species though not widely accepted) and can reach 52 cm in length. The haunting and resonant song of the Pulsatrix owls is as unique and fascinating as their appearance! This owl woke me from my tent at 2 am - I'd like to think to tell me that the rain had stopped but more likely there was some sort of territorial dispute going on because at least 3 were hooting up a storm and seemingly not too happy... they were always very high in the tall canopy so I felt lucky to manage a couple of photos.
Common in the lowlands, the Ferruginous Pygmy-Owl here was easily findable by day (elsewhere in their range I have found them more readily by night).



Also extremely common in the lowlands is the Tropical Screech-Owl. This is a familiar owl that readily hunts around lights and is not shy of humans. There are both grey and rufous morphs and this bird is an intermediate or brown morph.



As we move upslope in the eastern Andes, the Spectacled Owl shown above eventually gets replaced by their slightly smaller congenitor the Band-bellied Owl. The Band-bellied Owl is typically found between 700 and 1600 m ASL on the eastern slope of the Andes only (whereas the Spectacled Owl is found in the lowlands both east and west of the Andes and in Central America). In the Andes it is common for a species to be confined to a relatively narrow elevational belt on one slope or other and this is part of what gives the region such extraordinary biodiverity.  The most obvious difference is the brown barring on white underparts of the Band-bellied Owl and their dark eye colour.

This Band-bellied Owl was roosting in a dense bamboo stand at approximately 1300 m ASL along the road to Pacto Sumaco, Ecuador. Unfortunately heavy cloud and rain left me with very dark conditions for the photo.



At a similar elevational as Band-bellied Owl, we find the Napo Screech-Owl, a species that also goes by the names of Foothill Screech-Owl and Rio Napo Screech-Owl. However, not all authorities award this taxon full species status; some treating it as a subspecies of Vermiculated Screech-Owl. The differences within the Vermiculated Screech-Owl complex are very subtle (Napo Screech-Owl seemingly having a shorter song and perhaps slightly shorter wings and toes). This species occurs in a relatively narrow elevational belt in the foothills of the eastern Andes, rarely as low as 300 m ASL and sometimes as high as 1500 m ASL. I was lucky to photograph this owl at dusk along the road to Pacto Sumaco, Ecuador, at approximately 1300 m ASL (my first owl lifer of the trip).



Continuing up the eastern slope of the Andes, I met a famous mystery owl, usually referred to as the “San Isidro Owl” because Cabañas San Isidro near Baeza in eastern Ecuador is the very best place to see this species (and one of only a few locations where they have been recorded). The “San Isidro Owl” looks like a hybrid between Black-banded Owl and Black-and-white Owl; however, it occurs at higher elevation than either of those species (approx 2000 m ASL). The current thinking is that this might be an unnamed subspecies of Black-banded Owl, despite the fact that the song seems more similar to that of Black-and-white Owl. Further genetic studies are required to resolve this mystery. Despite the great mystery surrounding this owl, they are actually easy to see hunting moths under the lights at Cabañas San Isidro, where I took this photo. It was a great feeling to catch up with this avian enigma (even if it doesn’t really fit on any “list”).

Continuing even further upslope in the upper-level cloud forests and the high elevation temperate forests of the Andes (above 2000 and usually below 3600 m ASL) there is a fascinating species of screech-owl that is extremely difficult to see: the White-throated Screech-Owl. With their rich charcoal brown upperparts and warm buff underparts, their strongly contrasting white throat, and the lack of ear-tufts, the White-throated Screech-Owl is a very distinctive looking screech-owl (in a genus that is arguably characterized more by similarity than difference). They are also rather large for a screech-owl and can reach 27 cm in length. I had only previously managed poor looks at this species in Colombia and Peru, so I was delighted to finally succeed in photographing this beautiful owl in the thick but stunted moss forests along the steep walls of the Pululahua crater (west of Quito, Ecuador). Perhaps the lower canopy in this habitat increased my chances of seeing this species, but I felt it was an incredible stroke of luck when I spotted this bird, who was not vocalizing, at around 2 am in the light of a half moon, after a long night of hearing very little. The owl was kind enough to lean forward and look curiously at me while remaining partially hidden on the gnarled thick branch, which lends a lot of character to the photo in my personal opinion. I recall that moment, after the owl flew, when I nervously looked at the photos on the camera to see if they were sharp (I had been perched rather precariously on the steep slope and wasn’t sure if I had been able to hold steady or not). Although not a lifer, getting these photos was a trip highlight for me!


When crossing from the eastern Andes over to the western slope (over some spectacular high passes), the traveler encounters some very arid intermontane valleys, deprived of moisture by the massive rain shadow, and full of eerily strange vegetation combinations of gnarled montane scrub and cacti. It was in one such dry valley near Quito, known as the Jerusalem Protected Forest, where I encountered one of the most “diabolical” owls in all of the Neotropical Realm – and I mean diaboloical in the very best of ways, as in diabolically awesome! The Stygian Owl (Asio stygius), is named after the River Styx (Rio de la Muerte), which of course in Greek mythology was the gateway to the afterlife. In this owl’s case, it is the very dark, almost black plumage and the devilish long and close-set ear-tufts that inspired such a diabolical name (they don’t occur anywhere near Greece though, just to be clear). Indeed, in part because of their nocturnal haunts, owls have symbolism of death and/or the afterlife in many cultures from all around the world, but the Stygian Owl arguably best demonstrates that imagery. This is surely one of the most beautiful little devils anyone could hope to see!

In this case, I had gone to the dry intermontane valleys to dry out after so much rain only to get absolutely poured upon (rarely rains there they said – huh!). Amazingly though, I stumbled upon this awe-inspiring creature perched out in the light rain, after the big downpour, waiting for night to fall. Here are two photos, with and without flash (you can see the rain drops better when flash was used).  In case you’re wondering, the Stygian Owl is in the genus Asio and hence related to both the Long-eared Owl and Short-eared Owl but larger than either of those two species (reaching 46 cm) and darker. Stygian Owl is widespread in the Neotropics from southwest Mexico to northeasternmost Argentina, and also in the Caribbean, in a variety of forest and woodland types (but usually in slightly more open habitats).





Moving down the western slope of the Andes one expects to find the very dry forests produced by the massive Andean rain shadow. However, in northern Ecuador and southern Colombia, i.e. a small area around the Equator known as the Chocó region, the western slope of the Andes remain very wet and shrouded in cloud forest (very unlike the western slope in Peru and Chile). The Chocó region has many species not found on the eastern slope and its own set of endemics. My first target here was the Colombian Screech-Owl, who is only found on the western slope and only between 1300 m and 2300 m ASL and only in Colombia and Ecuador.

The Colombian Screech-Owl was only recently split from the Rufescent Screech-Owl (M. ingens) primarily due to vocal differences. Both species are extremely similar in appearance, although the lower tarsi are bare on the Colombian Screech-Owl, as you can see in these photos (versus feathered to the base to the base of the toes in Rufescent). Like many screech-owls, there are two colour morphs of Colombian Screech-Owl and I was lucky to find two individuals of the grey-brown morph, which I believe is much less common than the rufous morph. Although I had already seen one at Bella Vista, I was especially fortunate with this sighting at the great Reserva Las Grallarias in northwest Ecuador. Professional guide Dušan Brinkhuizen had found this owl calling from a day roost in the very early morning and I was able to find the roosting bird from his description of the spot. I waited in the late afternoon hoping to observe the owl become active. Amazingly, almost a half hour before sunset, the hour started preening and then flew to a low stump (followed by more preening), so I got to watch this bird in the dim light for over 20 minutes. I even tried experimenting by cranking up the ISO and taking some photos without flash. I have posted two photos here (with and without flash) for you to compare (the photo without flash is rather noisy but I still like it). Note also the pinkish eyelids.


I continued my descent of the western Andes and, although I managed to see my other targets in the Chocó region, the Cloud Forest Pygmy-Owl (Glaucidium nubicola) and Chocó Screech-Owl (Megascops centralis) I only managed very poor quality photos of them so I won’t be sharing those here. Nonetheless, it is worth sharing a few images of other nightbirds from this trip. Returning to the beginning, back down in the Amazon basin, I enjoyed fabulous looks at a day roosting Great Potoo. See if you can spot the potoo in the first photo with a wide-angle lens and then scroll or click forward to see the closer shots. With their exceptionally pale plumage, and subtle vermiculated markings, the Great Potoo can really blend against some of the whiter branches of the tall rainforest canopy trees. They pass the day perched as though they were a motionless branch and become active at dusk.



Higher up the eastern slope of the Andes, there is another potoo species that is notoriously difficult to see. The Andean Potoo is only found above 2000 m ASL and is one fo the most difficult potoos to encounter. This species is characterized by their white shoulder blaze. I consider myself very lucky to have been able to photograph this Andean Potoo on day roost near Cabañas San Isidro in a typicvally roosting position on a cercopia stump. Again, see if you can spot the potoo in the first wide angle shot before looking at the next two photos (increasingly closer). 




On the western slope at Refugio Paz de las Aves, I was able to photograph two members of the nightjar family thanks to Ángel Paz and his family. The first is a magnificent roosting male Lyre-tailed Nightjar on a cliff side. Amongst nightjars, this bird with their enormous tail is surely one fo the most spectacular!



The second was a Rufous-bellied Nighthawk on day roost and again I have shown two photos, one far and one zoomed in. 



I thought I would end this post with a photo of a day bird at night. This is a night roosting Great Tinamou. One interesting fact about Great Tinamou is that they spend the night in trees, unlike most other tinamous which sleep on the ground. This was not new to me so when I heard a calling bird at dusk I took the time to try to photograph them. However, I was very surprised when I eventually saw the bird and noticed that this bird has settled for the night on a large branch but was not perched with their toes gripping the branch but rather with the tarsi resting on top of the branch and the bird hence balanced on their tarsi (the toes were clenched shut but not gripping anything as can be seen in this photo). As bird have a tendon locking mechanism that enables them to sleep on the perch without falling off, I was surprised that this tinamou could sleep while balancing on their tarsi – they would need to sleep very still to maintain balance and avoid the risk of falling – a most unexpected discovery!

2 comments:

  1. Fine post… you certainly got some great owls in Ecuador - we visited in February this year but saw few, apart from San Isidro Owl.
    Great memories, we'll have to go back

    ReplyDelete

 
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