Cauca Valley (Colombia) Part III

Images of undisturbed subjects in their natural environment. All subject types.

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pbertner
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Cauca Valley (Colombia) Part III

Post by pbertner »

On location:

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Crab spider lying in wait within a lady slipper orchid:

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Jewelmark butterfly (Sarota sp.):

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Amblypygid:

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Scorpion under UV light:

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Ant (Ectatomma sp.) guarding treehopper nymphs:

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The trapjaw ant (Odontomachus sp.) has one of the fastest recorded movements in the animal kingdom. The springloaded jaws snap shut, releasing enough kinetic energy to kill any prey that blunders into the the trigger hairs.

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In my last post I touched on the difficulties of spotting Oophaga lehmanni in the wild, and its threatened status. After deliberating for a week, while cooped up with the flu and a sprained finger, and rummaging online for records of O. lehmanni, I was struck not only by the overall dearth, but by the almost complete lack of 'in situ' images, with not a single one illustrating behaviour or a decent representation of the environment. For a critically threatened species, one whose risk of extinction is quite high, this to me represented a tremendous oversight. Though I'd already tried and failed to capture some behaviour shots on a short previous expedition, I decided to dedicate a week to the endeavour, if for no other reason than to have a record befitting such an elegant species.

Travelling to the same site as before, I settled in to photograph calling behaviours. Setting aside a week to get this rather modest shot was giving myself quite a lot of latitude I thought...I was wrong. Three days in and I had little to show for my efforts, resorting to shooting at 300mm + 1.4X TC, I was still struggling to surprise this elusive gem. Though I could hear the frogs calling, and could even see them doing so, creeping up on them and getting a respectable photo was proving an altogether different kind of a problem.

I tried remote shooting (however they rarely returned to the same perch, causing the framing to be off), I tried hides (though after waiting 2-3hrs in mosquito infested areas with the slightest movement causing the frogs to go diving back into root tangles proved frustrating to say the least). Nothing seemed to work, and I was beginning to despair.

This begged the question, "Why would a poisonous species which supposedly has no known predators be so timid?" The answer somewhat surprised me, "researchers". Apparently the frequent capture-release monitoring of the local populations has resulted in a rather poignant behavioural change. A species which would otherwise be fearlessly hopping the rainforest understory has had its buzzing call muted. It was a potent reminder of our influence on the natural world, whether it represents a kind of Schroedinger's cat problem, in which our very observation and monitoring of a species ultimately impacts its natural behaviours, or whether it's something more intrusive or sinister like manipulation for an aesthetic image or poaching, respectively.

We have to go further in I told the guide. And so we walked, and we walked and still the frogs fell silent at the sound of our approaching footfalls. 6 hours later, 2 of which we left the already weedy trail completely to bushwhack, and we came to a spot where we crept up upon a calling frog. It continued its buzzing call despite undoubtedly having already seen us. I made sure to shoot without flash and with a long lens to prevent any kind of potential habituation/aversion. Moments later a second male appeared from behind a leaf and they immediately began to wrestle. They flipped one another repeatedly, interspersed with calls. Rather evenly matched, this went on for almost 15 minutes. Finally the victor held his ground, whilst the vanquished retreated from the hallowed ground.

Upon reviewing the photos and videos, I felt privileged to have witnessed such a behaviour from a vanishing species. This is perhaps even truer than I'd originally thought, the two males despite their verisimilitude actually appear to be different species/sub-species. While one has all the characteristics befitting O. lehmanni, the other whose white fingertips, slightly broadened head and differing banding patterns indicates some degree of hybridization with the very closely related Oophaga histrionica. Perhaps extinction will not come in the form of habitat loss or extinction (though harbour no illusions that this undoubtedly plays its role), but through hybridization, and its absorption into a larger more robust population. To purists and hobbyists this would still represent a tragedy, though perhaps it's a gentler swan song, a muting of a call rather than its abrupt silencing.

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Thanks for looking and commenting,
Paul
Last edited by pbertner on Thu Oct 18, 2018 12:37 pm, edited 2 times in total.

Lou Jost
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Post by Lou Jost »

Wonderful pictures and text. I have had the same trouble shooting poison arrow frogs decades ago, in a place far from researchers, so I am not sure that the behavior is unnatural. Maybe some predator has evolved immunity?

The ladyslipper appears to be the extremely Phragmipedium andreettae or manzurii....fantastic find!

tpe
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Post by tpe »

Great shots and very interesting story. Hybridization would be interesting, not only for one species declining but for the birth of another.

It also sets a question about the current classification, is it certain that white tips represent another subspecies (or whatever the definition would be if they are not geographically isolated) or just variation?

Your question about the cat comes in then as we would have to do some pretty invasive tests to check for sure. Italian scorpions have gained many species by zealous use of PCR as have Andorran grass hoppers but similar tests have also shown that there can be a lot of variation (Oddly often with white patches as this can often be the result of a single nucleotide variation) as in European blackbirds.

I would not want to be the one catching enough O. lehmanni to be sure, but perhaps collecting their faces could work?

Fantastic to see the behaviour, and well done for having the determination to stick with and get it. Getting a pic with a long lens would have put me off right away, but that and the number of mosquitoes i imagine to be there, eughhhh :).

pbertner
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Post by pbertner »

Lou - Do you recall the species/location? I've heard varying reports from researchers and casual observers alike. I've photographed a pretty varied assortment of Dendrobatids and this behaviour I would consider quite risk averse/affected. It's not like I was shooting with an MPE or even a 100mm, but with an effective focal length of 420mm at 3-5M and was still having issues. It seemed to be localized, since frogs further afield were less affected in their behaviours.

I'll post a full photo of the orchid in this thread, it would be great to get an ID. It was right off the road, so I'm not sure whether it is one of these rare species, but stranger things have been known to happen.

Tpe - Some great points. I'm not sure to what extent it would birth a new species since the hybridization would likely be the absorption and dissolution into the much larger O. histrionica population. It would also depend on the relative trait dominance of the two species (at least in terms of phenotypic expression).

The white tips is a feature which appears to indicate some degree of hybridization, since it wasn't found in isolated O. lehmanni populations but just those whose territories overlapped with its sister species O. histrionica. That said, genetic, behavioural, and in-situ studies are lacking in general for this species. However, taken together with the banding patterns and general morphological differences (and sympatric O. histrionica populations and other more obvious hybridization scenarios in the area) I am making an educated guess as to lineage.

It would certainly be interesting to do a more rigorous genetic test of the population, and I imagine that this may have already been done in Oophaga pumilio whose phenotypic variability is well documented in the Panamanian archipelago of Bocas del Toro, and has intrigued researchers for some time. O. histrionica shows a similar variability though to a lesser extent, so it's altogether possible that extensive testing could reveal an underlying phenotypic variation greater than formerly thought.

I'll have to chat with researchers as to whether individuals can be identified based on phenotype (jaguar spotting patterns, etc...) or whether it could only be done by tagging/genetic analysis.

Cheers

Troels
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Post by Troels »

Thanks so much for sharing your wonderful pictures and your remarkable knowledge.
Troels Holm, biologist (retired), environmentalist, amateur photographer.
Visit my Flickr albums

Lou Jost
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Post by Lou Jost »

Paul, my most recent experience was in the Choco lowlands of Ecuador, where Oophaga sylvatica evaded all efforts to photograph it. This was in the Canande Reserve of the Jocotoco Foundation, where no one manipulates them, but I suppose it is possible that photographers and tourists do pay attention to them.

But my most vivid experiences were with the Costa Rican form of O. pumilio, the same species you mentioned in the Bocas del Toro islands. This form is red with blue legs. This was in the days of film, in 1983, in a then-new undisturbed national park, Braulio Carrillo. Virtually no one had visited this park at that time; a road had been cut through it (now a super-highway between San Jose and the Caribbean coast) but there was an unfinished tunnel at one end and an unfinished bridge at the other end. The road company had gone bankrupt and had abandoned the project. In my six months of camping on that road I saw a human or two per month, and none visited the frogs, which were some distance from the road. This was as pristine as one could find; birds and mammals showed no fear of me.

I'll never forget the mosquitos I had to endure to photograph them while they were singing. I had to just let them bite; the slightest movement would scare them. There were so many mosquitoes that sometimes they even landed on the frogs. See my photos here:
http://www.loujost.com/Rain%20Forests%2 ... Frogs3.htm

However, I think your individuals were more skittish than mine. With patience (an entire morning or two) I did get pictures. I must have used my 90m Tokina f/2.5 macro, a very good lens which did give me decent working distance. I have a vague memory of taking a few with my 60mm Nikon macro, but maybe not.

The ladyslipper seems to be one of the super-rare recently-described species belonging to the group I mentioned; I think it is most likely P andreettae but could be P anguloi; I now think it is not P manzurii (which may not be a good species anyway).

See
http://richardiana.com/pdfRich/Richardi ... hlimii.pdf

Their natural habitat is on rocks near water seeps, but some roadsides provide good habitat too. Nevertheless the set of closely-related species I mentioned are rare and local, and classified as CR on the IUCN Red List, except P. schlimmii, the only common member of that complex. But P schlimmii usually has red spots on the staminode and is more intensely colored in the lip. This complex is of special interest to me because we (Fundacion EcoMinga) have recently bought the land containing the only Ecuadorian population of P fischeri, another member of this complex. We think that P anreettae may also exist nearby, and we would like to find and purchase a site with that species in order to protect it.

pbertner
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Post by pbertner »

Thanks Troels.

Thanks for the elaboration Lou. I'm terrible at ID'ing species, but here's a full flower shot. I can elaborate on the location and ecotype in a PM if you're interested.

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I'd love to make it out to Canande at some point, I've heard great things.

Interesting to note your experience with the dart frogs, it makes it more of a conundrum accounting for the different behaviours I saw in the different populations of O. lehmanni. Perhaps revisiting the site, or else looking at some of the other pops. of this species occurring in neighbouring districts is merited to more thoroughly test the theory.

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