All posts by sms14

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Night Hike

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Today we learned a valuable lesson in analyzing data. Statistics can help or hinder you and you must consider your question carefully to decide what kind of analysis to use. Different tests can give you different results, so you must be careful in considering your community and think about what will give you the most scientifically meaningful results.

After several lectures we took a short night hike and found spiders, cockroaches, insects and some people even saw a coral snake. The dry season has been particularly harsh and there is not much moisture, so I didn’t see any amphibians last night. They are probably hiding deep in the forest under the leaf litter or in other damp places.

Sophia Streeter

5-22

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Caves and Pitfalls

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Life in the canopy is very different from life on the forest floor. There are differences in water, sunlight, vegetation, other organisms, the affects of gravity and access to food and nutrition. Nitrogen is an important nutrient and decomposers on the forest floor are essential parts of the nitrogen cycle. With this in mind we hypothesized that the forest floor would be more nitrogen rich than the canopy. Specifically, that arthropods in the canopy are more nitrogen limited. We tested this using pitfall traps both in the trees and in the ground. We used control traps filled with water and traps full of nitrogen-rich liquid (our own urine). Tomorrow when we collect the traps we expect to find more arthropods in the urine filled traps, and more arthropods in the tree traps than the ground traps.

This afternoon we went spelunking in a cave at Las Cuevas that was used as a ceremonial chamber by the ancient Mayans. The Mayans believed that caves were entrances to the underworld and that at the end of the day the sun turned into a jaguar and entered hell through a cave to battle demons all night until it reached the other side. This cave had nine bottlenecks that represented the nine layers of a hell a Mayan hero fought through in their mythology. We belly-crawled through the mud-guano cave floor to several hard to reach spots. There are many Mayan artifacts in the cave and areas are still being excavated by archaeologists. We found a lot of pottery, but also a human femur and an animal skeleton. Most excitingly, we saw wrinkle-faced bats roosting. Other animal sightings included glow worms and whip scorpions. Of course the formations are almost alive themselves, with huge chambers swallowing you up.

I have been searching for amphibians in damp areas like the cave entrance and inside bromeliads but I haven’t had any luck today. The leaf litter can also shelter cryptic amphibians, like toads, but I haven’t found any so far.

DSCN2573

Sophia Streeter

5/21

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Ant Day

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Today we focused on some of the many ant species that habitate the Chiquibul forest. The cecropia tree has a symbiosis with azteca ants, which protect the tree from predators in exchange for shelter and food. We spent the morning testing a few hypothesis about how the cecropia trees avoid herbivores before they are colonized by the protector ants. 

This afternoon we excavated three leaf cutter ant colonies of different maturities. Once a queen colonizes a nest after a nuptial flight she can live for 20 years reproducing, expanding the colony until there are millions of ants at any given time. There are tunnels underground leading to chambers full of the ant’s fungus garden and pupae. The youngest ones are fairly small, but once they are 10 years old they get huge, with tunnels the width of your arm full of soldier ants ready to come out and attack you when you disturb them. They have quite a pinch and we were all thankful for our rubber boots today.

We had an unexpected amphibian sighting once we got back to our housing; one of the bedrooms had a large frog on a bedpost. I caught it and took it outside to get a closer look and try to identify it. It hiccuped in my hand, puffing out its chest, in protest to its capture. The frog was dark green and brown, with some stripy markings around the forelegs. I couldn’t examine its back without it jumping from my hands so I didn’t get a clear look. It was about 2.5 inches long with horizontal pupils, bronze irises and toe pads. The toe pads indicate that its a treefrog and since there aren’t many in the area I would have to guess that it was another common Mexican treefrog, based on size and color. I released it into the trees after a minute or two to not cause it too much distressed and it leapt from my hands with a defiant squeak.

Digging leaf cutter ant nest

Sophia Streeter

5-20

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Camera Traps

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Our 13 mile hike in the rainforest, up and down hills, was the most physically exerting thing I’ve done in a long while, but it left me full of endorphins and with pleasantly sore muscles. We hiked all this way to set up 12 camera traps that will take pictures every time they detect movement over the next 5 days, until we collect them again. Hopefully this will let us see some of the more shy animals of the rainforest. We also found several interesting insects, spiders, and birds over the course of the day.

Amphibian update: we found some tadpoles in the muddy reservoir left by a car tire. Not an ideal spot but the dry season is coming to an end and there aren’t many options left for frogs and toads in the area, who need water to reproduce. More excitingly, I saw my first treefrog of the trip this afternoon. Adrienne masterfully caught it and held onto it long enough for me to snap a picture and identify it. After some consideration we positively identified it as a Common Mexican treefrog. It was large, at least 2.5 inches, and a shade of grey with green tinges. Once we were able to see its back, its species was obvious. It had the telltale darker splotches on a grey-brown body. At first its dark-eye patch threw me off but amphibians can be highly variable in coloration within a population and aren’t always a reliable form of identification.

Map of Las Cuevas

Mexican Treefrog

Sophia Streeter

5-19

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Caracol & Las Cuevas

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Today we completed our journey south-west through Cayo and into the Chiquibul rainforest. On our way to our home camp at Las Cuevas Research Station we took an anthropological detour through Mayan ruins. We were guided through the Caracol Archeological site and climbed up and in and down the ruins and tombs. Even though it was mostly overgrown and covered by years of sediment the pyramidal structures still stood and it was easy to image the bustling metropolis it was 2000 years ago. Hearing about the (hypothesized) reasons for its decline was ominous; overpopulation, agricultural collapse, drought… sound familiar?
Even though its citizens are long gone the city is still full of life. Almost everyone found an animal from their taxonomic group—bromeliads, philodendrons, birds, mammals, and a plethora of plants. The highlights included an edible red fruit (you suck on the seeds but don’t eat them, looks like gunk, tastes like papaya), toucans, a coati and a blue crowned mot-mot.
Sadly there were not any amphibians around for me to identify. The area was much too dry to be a suitable habitat. Amphibians require a damp habitat because they experience high evaporative water loss through their skin. Most also require water for reproduction. Caracal was in the forest but it was not dense enough to retain the moisture necessary for most amphibians. Here in the forest surrounding Las Cuevas should be a much more habitable medium and we can expect to see a variety of species in the next few days.

Caracol

Sophia Streeter

5-18

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The beginning

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Travel was smooth and breezy. It’s amazing to have everything all planned out for you so you don’t have to worry about transportation or lodging or food, I almost feel spoiled. Now I can worry about more important things- like tropical field biology.

We are staying at a beautiful lodge called Crystal Paradise and already have seem a surprising amount of flora and fauna, considering we’re not even in the jungle yet! In terms of amphibians there have been two cane toad sightings. I will try to get some pictures to share with you as we go on. There have been insects, arachnids, a large boa (I get to check that off my Belize wishlist now), and a plethora of trees and flora. The scenery was beautiful driving across the country, but I admit it mostly just looked like a bunch of trees and green stuff to me. I was glad for Sam’s lecture on the rainforest canopy, which was very helpful in starting to separate out the different kinds of plants and their relationship to one another.

Cane Toad

Sophia Streeter

5-17

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Pre-departure fugue

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The night before a big trip never phases me the way it should. I pack, I sleep, and the next day I find myself somewhere else and just roll with it. I always feel like I lack the appropriate level of enthusiasm (whatever that it), but it beats travel anxiety so I don’t worry about it too much. The enthusiasm returns once I’ve settled in, and all is well. I worry and pick over everything else but travel is like “well, I guess I’ll get there somehow.” Perhaps this is some kind of physiological adaptive response to environmental stressors…

I look forward to returning to Central America in biological pursuits once again. During my 5 week conservation trip in Panama I really only worked with two species– Loggerhead sea turtles (Caretta caretta) and Hawksbill sea turtles (Eretmochelys imbricata)–so the breadth of my experience is limited (a generous way of putting it). I feel like I’ve barely skimmed the surface of all there is to know tropical field biology. I’ve read all kinds of books and primary literature, looked at pictures and diagrams, even experienced it first-hand in some of my trips abroad but it still feels like I know squat. There is just too much cool stuff!

Speaking of too much stuff, fingers crossed that we don’t encounter anything I don’t have on my taxonomic ID cards. Annelids and hydroid identification is fairly simple, but amphibians are a whole other story. There is clearly one very good way to avoid detection by predators because there are some pretty similar-looking frogs out there. Also I worry that some of my sources may have been a bit dated (2000 isn’t that long ago, right?). I tried to mentally absorb as much information as I could from a bunch of sources in the hope that some of it will be useful. Despite all this I genuinely enjoyed reading about amphibians even though I’ve never had any particular interest in them before. I look forward to developing even more new interests during this trip.

Sophia Streeter

5-16