Ecuador and Thermal Scoping

Eileen and I just got back from 20 days in Ecuador on a birding tour (“Jewels of Ecuador”), run by Field Guides, Inc., with whom we have previously traveled to Kenya, Brazil, and Thailand. The group was fairly small, with 7 participants, simplifying the logistics as everyone could fit in a single vehicle (a small bus). The tour was led by Mitch Lysinger, who was great, and we had four days before the main tour began, being guided by Andres de la Torre, who even knew most of the flowering plants we saw!

We had previously been in Ecuador once, in 2011, spending a week on our own in La Selva Jungle Lodge, on the Rio Napo in Amazonian Ecuador. In contrast, the present trip focused on the Andes and foothills, in both the North and South, filling in most of the remaining principal biogeographical areas in the country.

Ecuador is considered by many to be the best country in South America for birding, because it has a high species list in a small geographical area, which is safe, has good infrastructure, and is quite easy to travel through. The high biodiversity of Ecuador is a result of its straddling the equator (there generally being higher species densities at lower latitudes) and, critically, its being bisected, roughly from north to south, by the Andes. In some places the Andes are split into two parallel cordillera, with a high, dry intermontane valley in between.

Very different assemblages of birds occur east and west of the Andes, and at different elevations on the two slopes. There are a large number of species and subspecies pairs, with one representative east of the mountains and one west, which evidently were at one time continuous populations. These populations were then split and isolated by the uplift of the Andes, the two sub-populations then adapting to their local conditions and evolving into distinct entities.

We birded in a number of different habitats while in Ecuador. Some of the most important included: (1) choco, a tropical rainforest at low elevations in northwest Ecuador, nearly all of which has been cleared; (2) subtropical forest, found at moderate elevations on both slopes; (3) temperate forest, found at higher elevations in the Andes; (4) dry, intermontane valleys, such as the Catamayo Valley west of Loja, where a number of “Tumbesian” species (named for a district in northwest Peru) reach the northernmost extent of their ranges; and (5) paramo, grassland found above the treeline, which typically starts at around 12,000 feet of elevation.

One of the principal draws of Ecuador is the remarkable assemblage of hummingbirds. Hummers are found only in the New World. If you plot hummingbird diversity against latitude, the resulting curve is bell-shaped, peaking near the equator, and dropping off going north towards North America, and south towards Tierra del Fuego. The U.S. has only 14 regularly breeding species, whereas Ecuador hosts around 130 species (more than any other country), out of about 340 species in the world. On this trip, Eileen and I saw 54 species well, and the group recorded several additional species.

Although virtually all the areas we visited were very good birding, a few stood out. The tower at Rio Silanche Sanctuary, in the choco of the Northwest, provided hours of fine birding from a single vantage point. The Catamayo Valley in the South, west of Loja, had a fine selection of Tumbesian endemics. The Mindo area, northwest of Quito, had a concentration of excellent sites. And San Isidro Lodge and environs, on the east slope near Cosanga, offered nice, varied birding in subtropical forest and opener areas.

Some of our favorite bird sightings of the trip were of Shining Sunbeam, Booted Raquet-tail, Chestnut-breasted Coronet (all hummers), Andean Gull, Plumbeous Hawk, Mottled Owl, Black-banded (“San Isidro”) Owl, Crested Quetzal, Coppery-chested Jacamar, Toucan Barbet, Plate-billed Mountain Toucan, Crimson-Mantled Woodpecker, Ornate Flycatcher, Cinnamon Flycatcher, Slaty-backed Chat-Tyrant, Green-and-Black Fruiteater, Andean Cock-of-the-Rock, Club-winged Manakin, Turquoise Jay, White-capped Dipper, Green-and-Gold Tanager,  Golden Tanager, and Black-faced Dacnis. In total, we saw 417 species of birds in Ecuador, about 40% of which were new species to us. Eileen and I have now seen 3360 and 3247 bird species, respectively.

Many other highlights come to mind. We saw lots of flowering plants, especially at higher elevations, with a number of the species being quite showy. The paramo was enchanting and in some places very scenic, such as in Cajas National Park. In paramo at Cayamba-Coca National Park, we found two challenging and interesting species, Rufous-bellied Seedsnipe and Andean Snipe. At several locations we were able to see large numbers of moths that had been attracted overnight using lights rich in ultraviolet light; the variety of moths was amazing!

Although mammals were scarce, we had five species in one day on Volcan Antisana, and during the trip as a whole we saw three new species: Brazilian Cottontail, South American Coati, and … Spectacled Bear! We saw the latter twice, each time at high elevation, feeding on the hearts of bromeliads that resemble some of our yuccas. Spectacled Bear occurs only in the high Andes, and is the only remaining species of the short-faced bear complex, which otherwise disappeared during the Pleistocene (including one species that was probably the largest mammalian predator ever found in the Western Hemisphere).

Last year I reported how well our new thermal scope worked in finding mammals in Panama. On this trip to Ecuador, I explored how it could be used in birding, beyond that obvious application of locating nocturnal birds. It turns out that it was surprisingly useful in a number of situations. The rest of this post provides more detail on use of a thermal scope in birding.

As a review, thermal scopes are imaging sensors that are sensitive to far infrared radiation – heat, basically – but are insensitive to shorter wavelengths such as visible light. The image produced by a thermal scope is basically a heat map, showing how much thermal energy is being detected by each pixel. In the ideal case, the surroundings would all be at equilibrium at a low temperature, against which background a warmer target (such as a mammal) would stand out as a brighter feature.

Given the very low resolution (ours is 384×288 pixels, only about 0.1 megapixels), and the distances and focal lengths involved, the image of a mammal or a bird is typically just a blob, or maybe a main blob (body) and auxiliary blob (head), unless it is really close. So in most cases the thermal scope is useful for detection, but not identification. It can be challenging to locate an animal visually after seeing it in the thermal scope, because the scope is completely insensitive to visible light, so it can be hard to pick out infrared “landmarks” that correspond to visible ones. In addition, it is very hard to judge distance, except by moving a bit while looking through the scope, in an attempt to observe the animal being occluded by branches or other obstructions, which provide clues regarding what is in front of or behind the animal. Fortunately, all of this becomes a bit easier with practice.

The thermal scope works especially well at night for two reasons: (1) Without sunlight heating the surroundings unevenly, the terrain is usually quite uniform in temperature, giving a fairly “simple” background from which the animal stands out. (2) The surroundings generally cool off at night, leading to a larger temperature difference between the animal and background, resulting in a stronger “signal”. But it can be used with surprising effectiveness in daylight, as long as the immediate environment does not vary too much in the amount of light received. For example, a densely shaded forest can be suitable for scanning, and even open or partially open areas can be amenable to thermal scoping if the day is overcast. Given the often rainy, misty, or cloudy weather of Ecuador, I found that I could use the thermal scope effectively about half the time during daylight hours.

Here are some examples of cases where the thermal scope was helpful in seeing birds: (1) Under foggy conditions in the paramo, two Andean Snipe were located, which the group had walked past. Because the thermal scope is only sensitive to very long wavelengths, it is hardly affected by Rayleigh scattering. Consequently, the images can be quite clear even in the presence of fog or smoke, providing a better view than with visible light. (2) A number of motionless, silent birds were found perched in camouflaged situations; these included Club-winged Manakin, Golden-headed Quetzal, and Viridian Metaltail (a hummingbird). (3) Skulking birds initially detected by other means, moving about but staying hidden in dense foliage, could sometimes be tracked until they briefly appeared in a hole where they could be seen. Examples include Plain-tailed Wren and Ash-colored Tapaculo. (4) Of course, thermal scoping is especially helpful at night; it made short work of a Mottled Owl, which could have been difficult to find otherwise. It was also helpful at night in seeing Western Lowland Olingo (a member of the raccoon family), and finding an occupied Orange-bellied Euphonia nest (the opening of the nest showing as a perfect disk, warmed by the female inside).

Thermal scopes are rapidly revolutionizing mammal-watching, having been adopted by many enthusiasts in a remarkably short period of time. I expect their entry into birding will be quite a bit more gradual and ultimately involve a smaller percentage of people, but I think they will have an impact, especially if prices drop further. Although the model we have is no longer available, a similar one, the Pulsar XQ28F, currently sells for $2400 on Amazon. There are many night vision devices available, but this may be the lowest-priced one that is genuinely valuable for finding mammals and birds under a reasonable range of conditions.

We plan to hit the road by the end of this month, so watch for a new blog post in late March.