Sunday, May 6, 2012

Trinidad on my mind: of guppies, snakes, dogs, and testicles.

I first started working in Trinidad in 2001 and, in 2002, I started sampling guppies from large numbers of sites from two rivers (Marianne and Paria) on the north slope of the northern mountain range. These samples were used to characterize variation in traits and genetic makers so as to infer how interactions between selection and gene flow influenced adaptation. This first project ended in 2004 and it had been great fun exploring, climbing over waterfalls, and trying to find viable guppy populations throughout the spider-web network of these two nearly pristine rivers. I therefore figured it would be a good idea to come up with an excuse to keep visiting. My students have since done many projects but I also created a project of my own to make sure that I came back every year and went to the coolest remote sites. I therefore selected 10 sites to start a long-term sampling protocol– ten sites that were not only biologically interesting but that required walking long distances in beautiful streams and camping in remote areas. This year marked the 11th year visiting these sites and I have now amassed 5327 guppies (about 50 per year) from these 10 sites alone (many more have been sampled from other sites). The idea is to use these long-term samples to study eco-evolutionary processes as they act through time and space. With more than 10 years of working in Trinidad, it seems a good time to go back to my notes and dig up a few interesting events that occurred.



I think I see a guppy.

2012: This afternoon, Gregor (Rolshausen) went off to catch fish. When he came back to our house (Indra’s) after dark, he had a 2 m long snake with him. Apparently it had been tangled up in his windshield wipers when he had gotten back to his car. He wasn’t sure if it was alive or dead – or what kind it was – and so he had gone and asked the guards (he had parked his car at a water authority – WASA – station) if they could shine a light on it for him. The guards were very excited and apprehensive and brought a heavy metal pipe with them to use as a weapon. When they saw the saw the snake, however, their braveness evaporated and none would go anywhere near it. When Gregor removed it from the wipers they said, accusingly, “what are you, some kind of snake man or something”?


Snake man.
2011: Stayed home (Indra’s) and processed fish. The crew (Felipe Perez, Kiyoko Gotanda, and Maryse Boisjoly) drove off the Simla to check their email. I was in the kitchen when they returned. “Andrew, come quick right now” they shout at me. They seem all crazy, almost panicked.”Damn,” I think “Who’s hurt.” But then it becomes clear they are excited rather than scared. “You’ve gotta come here right now you’ve gotta see this.” “Do I need my camera,” I ask. “Definitely!” Ah, so it is something cool. I approach the car but rather than all of them piling back in to driver somewhere, they sort of stand away, as though the cool thing is actually in the car. Sure enough, there on the shelf below the back window is a tropic screech owl. It seems that they were driving along the road and the owl actually flew in the window, hit Felipe’s head, and then the back window. They had all yelled in surprise and pulled the car over to figure out what happened. The owl had seemed rather dazed – sort of sitting there but drooping, with its eyes closed – and so they simply drove back to Indra’s. We spent the next half hour taking pictures (just a few) and watching as the owl slowly seemed to recover. It eventually flew off - quite a unique experience.


The owl in the car.
2008: I walked up the Petit Marianne twice this year. Each time while walking through the village of Avocat, a healthy looking, smallish, golden dog started walking with us. He didn’t seem needy, or begging, or aggressive – it just seemed like he wanted to go for a walk. Dogs rarely follow us in this manner in Trinidad, and those that do invariably give up soon - but not this dog. He was right with us all the way to the falls, then up over the hill, and then all along the length of the river with us for several hours. At first I wasn’t favorably inclined to having a dog along, but it was such a consistent and pleasant companion, that I warmed to it. When we stopped for lunch, I gave it a PBJ sandwich – but it wasn’t interested. This piqued my interest even more – the dog clearly wasn’t along just for the food. After sampling, the dog accompanied us back to our other sampling sites on the main stem of the Marianne. He would curl up and sleep beside our equipment while we were sampling. Then it stayed with us again on the way out until we reached Avocat, where it disappeared. Our second day on the Petit Marianne, he did the whole hike with us again and then stayed by the car as we took our gear off. Amazing, he would stand in the way of cars coming down the road and growl at them – as though he was protecting us. Needless to say, we were beginning to think this dog wanted to adopt us; so when we drove off, we did so quickly. It immediately ran after us at top speed, really fast actually, barking plaintively. In other circumstances, I might have kept it. A final note: when the dog was facing off with cars on the road, another man was there waiting for a ride. He lived at Avocat and knew the dog. I related to him how the dog had reacted to us on both of our hikes and his simple answer was: “Oh that dog – he likes white folks.”


Our campsite on the Paria River.
2006: Yesterday I took my annual camping trip into the Paria, this time with Martin Turcotte, Ian Paterson, and Paul Bentzen. We saw lots of cool stuff, particularly two fer-de-lances, both of which I walked within inches of before someone behind me spotted them. I must look very carefully only where I put my feet. This stops me from stepping on snakes but I miss many that are VERY close. In fact, this is at least the fourth snake I have walked right past (yes, I have seen others before walking past them). We saw one on the way into the camping site and one on the way out (see photo). This second time, it was becoming dark and watching for snakes given our new-found piety made us go quite a bit slower. [As of 2006, I have now seen 8 fer-de-lances in approximately 12 weeks of work in Trinidad.] Oh, and lest I forget: a major breakthrough on the splinter! I was squeezing hard all day getting puss out. Eventually I squeezed so hard that the pus was welling up like magma and all of a sudden, pop, out comes the splinter – floating on the pus like the negative of a marshmallow floating on hot chocolate.


Just missed.
2005: We found two small pools (1-2 m squared) right at the silk cotton tree, each with vast numbers of guppies. We captured 41 females, 32 males, and hundreds of juveniles in one and 42 females and 31 males in the other. These were probably less than half of the actual number of guppies in each pool. These pools are isolated from the mainstem although they would be flooded in moderately high water. The males were very colourful in relation to mainstem guppies just a few yards away. They are probably the most colourful guppies I have seen, although the amount of orange is low. Instead they have large patches of yellow, pink, purple, etc. I suspect that conditions in these pools are very different from the main stem of the river and that the evolution of high colour owing to female choice proceeds within them during periods of isolation only to be reversed owing to predation when they are washed out during the next flood. It would be very interesting to examine the dynamics of this interaction. I took a sample with this in mind. (Note: I still haven’t done this examination as of 2012).



Paul Bentzen catching guppies.
2003: ... At this point David Reznick had worked his way down the cliff and reached the tree. With remarkably little hesitation he sacrificed his testicles to the 6 inch tree by leaping forward, straddling it, and sliding ungracefully downward, taking the bark with him as he went. Mike Kinnison, who was just above, heard and saw David’s farewell to future children and filed this away for future reference – which turned out to be needed in the immediate future. I climbed up the steep rocks to the base of the sacrificial tree, with Mike immediately above. He lowered the pack and then his eyes lifted to survey the tree, as though seeing it for the first time. “I’m supposed to jump to that?” he asked, knowing the answer but somehow not accepting. All he could now see in his mind’s eye was David spread-eagled on the tree loudly decrying the state of his testicles. “Is there any other way?” “Well” I said “I suppose you could go up and around but I don’t know if you will find a way that is any easier.” Mike looked uncertain. He knew he didn’t want to go back up that horrible cliff but he also knew he wanted to have children. His eyes moved up and down the tree as I waited not-so-patiently below, as if I might catch him should his jump not go so well. After some moments of hesitation and in a wondrous display of counter-intuition, he leaned out and fell slowly forward until his hands were on the tree and his feet, almost horizontal behind him, were on the ledge. Perched there, with no way back, his eyes clinically scanned the cliff below him. “Maybe I could just walk down the cliff” he asked in defiance of all logic. “Damn it Mike, jump” And jump he did, ever so much more graciously than had David, informed no doubt by David’s demonstration of how not to do it. (Note: Both David and Mike have subsequently had children.)


The site of David's and Mikes' sacrifice.
Stoies abound – and these are just a few of them. Here’s looking forward to having new ones in the years to come.

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