Quick visit to our Rio Zunac field station

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The Rio Zunac forest in the morning mist. Click to enlarge. Photo: Lou Jost/EcoMinga.

I’ve just come back from a three-day trip to our field station in the Rio Zunac Reserve. It was a very rainy three days, but there are always interesting things to see in this reserve, even in the rain.

The station is four and a half to five hour’s hike from the road when carrying a heavy pack. This entrance hike is always exciting, especially now that we know a certain segment of the entrance trail is guarded by a large, deadly pit viper, Bothrocophias microphthalmus. On this trip I had to work hard to control my nerves as I hiked through the spot where he lived. I’m happy to report that my search image for this species is now much better tuned than it was when I unwittingly walked right past him, almost touching him, on Dec 11. That was the first time anybody had seen the species on this trail. Now that I know what to look for, I am spotting him every time I come here, always within a few meters of the original spot where I almost stepped on him. This time he was easy to spot, because he was moving slowly. It was an interesting movement, a slow crawl in a straight line rather than a curving motion. Then he gracefully tied himself into a coil in a fascinating motion worthy of the special effects in a Hobbit or Harry Potter movie. Here he is after making this coil:

Bothrocophias microphthalmus, the Small-eyed Toad-headed Pit Viper, the same individual as in last week’s post, on the Rio Zunac entrance trail again. Photo: Lou Jost/EcoMinga.

It was a relief to get past that spot. After that, the skies were sunny, Andean Cocks-of -the-Rock were everywhere, and I enjoyed a beautiful hike. About an hour and a half from the station, I saw a miniature orchid belonging to the genus Neooreophilus , formerly called Oreophilus, and before that Brachycladium, and before that Lepanthes. Mark Wilson, Sebastian Vieira, and I are working on DNA analysis of this group to settle some of the species-level and genus-level uncertainties. More about that in a future post. For now I just want to show the crazy flower (N. hippocrepicus):

Neooreophilus hippocrepica, a miniature orchid. The green leafy thing in the left front of the image is actually a tiny blade of moss. Photo: Lou Jost/EcoMinga.

When I got to the station, I found a tame Russet-crowned Warbler (Basileuterus coronatus) foraging in our yard. Warblers are generally active arboreal birds, but this particular individual was often on the ground, nearly at my feet. At first I thought it might be sick, but its acrobatics suggested good health.

Russet-crowned Warbler at the Rio Zunac field station. Photo: Lou Jost/EcoMinga.

Russet-crowned Warbler at the Rio Zunac field station. Photo: Lou Jost/EcoMinga.

These warblers are in the same family (Parulidae) as the colorful migrant warblers that excite North American birdwatchers. (They are not closely related to the birds Europeans call “warblers”.) Those North American warblers actually spend most of their lives here in Latin America; the more northerly breeders spend only three to five months on their breeding grounds in the north. A recent DNA-based warbler phylogeny seems to show that the permanent resident South American warblers, like this Russet-crowned Warbler, evolved from migratory warblers who got sick of making the long trip. However, I think this is still a debatable issue. It will be interesting to look at the ages of these lineages, to see how they match the geological history of continent movements.

Nightfall at the station brought a torrential rain, three inches of water, most of it falling in just a half hour of deafening noise, complete with thunder and lightning. Then slowly a new sound rose up from the ground itself, like many parallel trains running past the cabin on noisy tracks…the rocks in the nearly riverbed were being carried by the rising floodwaters and were crashing into each other, making a continuous staccato of peculiar dull hollow banging sounds. This train of boulders kept streaming past for an hour or two, until slowly that sound died out and was replaced by the more familiar roar of raging rapids.

It rained a lot the next day too, so I didn’t see much except Cocks-of-the-Rock, all in poor light. One poor photo I took:

Cock-of-the-Rock in the rain. Photo: Lou Jost/EcoMinga.

It is hard to beat Juan Pablo Reyes’ Cock-of-the-Rock photo in the banner for this blog, but he has other good ones too, and in honor of all the Cocks-of-the-Rock I saw on this trip, I put another of his great shots here:

Andean Cock-of-the-Rock in the Rio Zunac Reserve. Photo: Juan Pablo Reyes/EcoMinga.

I also saw a new bird for our reserve, a Grallaricula antpitta, a small inconspicuous insectivore. I just barely saw it; there was so little light in the rainy understory where it perched that I couldn’t even make out any color or pattern, just its distinctive silhouette. My electronic camera, however, managed to capture an image. The bird and camera both moved too much to make a decent picture, but the resulting ghosted image conveys some information about its species identity. It’s an Ochre-breasted Antpitta, Grallaricula flavirostris. I placed the blurry photo alongside a real photo of the Ochre-breasted Antpitta taken by Roger Ahlman (http://www.pbase.com/ahlman/news), who kindly gave permission for us to use his photos on this blog.

Ochre-breasted Antpitta. Left photo: Roger Ahlman. Right photo: Lou Jost/EcoMinga.

While waiting for the rains to stop, I saw an interesting experiment our guards had tried. In May John Clark and David Neill found a curious hemiepiphytic Blakea (Melastomataceae) with big fragrant flowers. (A hemiepiphyte is a tree that starts life as an epiphyte growing in the branches of another tree, eventually sending its roots to the ground). As part of our “Protecting the Fragrances of the Amazon” program financed by Reckitt-Benkiser (Airwick), we wanted to try to propagate this plant to study its pollinators and its fragrance. This can’t easily be done when the flowers are tens of meters above the ground, so our creative guards Luis and Fausto Recalde, using their experience as arborists, grafted buds of the Blakea onto stems of related trees growing around our station. I was pleased to see that at least one of these buds has survived and is now growing! If this works generally, it opens new possibilities for propagating the fancy melastomes we have been discovering in our reserves, like Blakea attenboroughii and Meriania aurata.

As-yet-unidentified large fragrant Blakea species from the Rio Zunac Reserve. Photo: John Clark.

A sprig of the unidentified fragrant Blakea grafted into the trunk of another melastome by our guards, Luis and Fausto Recalde. This graft was made over a month ago, and appears to be growing. Photo: Lou Jost/EcoMinga.

The next day it was already time to go back home. Once again Cocks-of-the-Rock were scattered through the forest like Christmas ornaments. On the trail home I found a rock with a broken snail shell on it. I think this was the work of the Giant Antpitta, Grallaria gigantea, a close relative of the little Ochre-breasted Antpitta I had seen the day before.

Giant Antpitta in the Rio Zunac Reserve. Photo: Santiago Recalde/EcoMinga.

The Giant Antpitta is a rare bird whose east Andean race (the one found here) is only known from three or four localities. They generally eat earthworms, especially the meter-long Giant Earthworm, but I have seen them here hammering at snail shells that they wedge into suitable hollows in rocks. Our guards have found some rocks with large piles of broken shells, suggesting re-use of these special rocks. This bird appears to use the rock as a tool, just like the rock anvils used by the capuchin monkeys to crack palm nuts in my earlier post. The capuchins add an additional layer of complexity, since they need to use a second rock to break the shells of their nuts. The antpittas just use their beaks. Still this simple use of an anvil is an important indication of cognitive plasticity in the antpittas. A similar use of a stone anvil to break snail shells was recently documented in a related bird, the Great Antshrike (Taraba major). (The conclusion of the Great Antshrike study was that this behavior was recently learned in response to the accidental introduction of non-native land snails to the area. There are many native snails in most forests inhabited by this antshrike, so I don’t believe that part of the study’s conclusion.)

Broken snail shell on an anvil rock (used by the Giant Antpitta ?). Photo: Lou Jost/EcoMinga.

Anvil rock used (by the Giant Antpitta?) to crack snail shells. Photo: Lou Jost/EcoMinga.

About an hour later a Highland Motmot (Momotus aequatorialis) at close range took my breath away. It was doing an odd tail display I had never seen before. As usual when I see beautiful things, I had recently packed my camera into my waterproof backpack to protect it from the rain. I knew the motmot wouldn’t just stay there watching me and doing its display while I took off my pack, unpacked the camera, etc, but I did it anyway, and the bird stayed! In a minute I found out what may have caused the display, as a small monkey, the Saddle-backed Tamarin, made an alarm call just above me. The bird may have been making a threat display at the monkey. My pictures of the monkey were worthless but the motmot photos were decent.

Highland Motmot displaying in the Rio Zunac. Click to enlarge. Photo: Lou Jost/EcoMinga.

Highland Motmot in the Rio Zunac. Click to enlarge. Photo: Lou Jost/EcoMinga.

Here’s a Wikipedia image of the monkey species that seemed to have been triggering the motmot’s display:

Saddle-back Tamarin. Wikipedia commons.

When I got to the footbridge over the Rio Zunac, I could get a feel for how much the river must have risen at the height of the flood two days ago. Crushed vegetation and washed-up logs showed the water level must have been about four meters higher than now, and the present level was itself a meter higher than when I entered.

Rio Zunac two days after the downpour. Photo: Lou Jost/EcoMinga

The same segment of the Rio Zunac during normal times. Photo: Recalde/EcoMinga.

But this was nothing— three times in the twenty years I have been here, the river rose so high it washed over the bridge and carried off its floor. Such a big flood seemed unbelievable as I stood on Bridge 3.0, eight meters above the water, but the bent cement bridge supports still tell the tale:

Footbridge over the Rio Zunac. The cement posts were bent in earlier catastrophic flash floods. Photo: Lou Jost/EcoMinga

Finally the moment I had been dreading, the Field Biology Final Exam. Would I spot the pit viper on the side of the trail and pass, or would he be hidden beneath leaves and strike me? It was now doubly unnerving. Probably if I didn’t know he was there, I’d walk briskly past like I always had, and most likely I wouldn’t get bit. But now that I knew he was there, it took me ages to cross through that segment, because I stopped after every little step to try to find him. Sure enough, there he was, just a meter or two from where I left him two days earlier, moving faster than normal, apparently heading for shelter as the rain began again. It was always a relief to see him, since a seen snake can’t kill. Two days ago I had regretted not making a video of his fascinating coiling movement, so this time I was ready. The snake didn’t make any great moves, and soon went under a log to avoid the rain, but I still got decent video in spite of the conditions (bad light, camera shake, autofocus getting tricked by leaves and blades of grass). The background noise is a rushing stream a few meters away (I set the default in Youtube to “Mute” so you don’t have to listen to it):

A few minutes after I left the spot, I ran into a family of local people heading into the forest. An old man, who had a finca up the trail, plus his daughter and her 7 or 8 year old kid. A kid who would die in seven hours if bit by this snake (Campbell and Lamar 2004 p 329). I explained the issue to them, and I think they got the message, since the kid decided to ride on his grandpa’s shoulders. But they didn’t seem to understand my description of the exact place. So I walked with them through the spot; the snake was unseen, still beneath its log. I am sure the next time that family crosses the spot, they will see the snake too, and kill it.

Note added Dec 29: We all agree we have to move this snake. If it were inside our reserve boundary it would be alright, but since it is in a public trail often used by clueless people, someone will surely get bit if it stays there.

Lou Jost
www.loujost.com
www.ecominga.com

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