Tag Archives: Cecropia

Day 8: A jaguar does somersaults

Today we left Las Cuevas very early in the morning. From there, we drove three hours to the ATM cave. ATM is an abbreviation for a Mayan phrase Actun Tunichil Muknal meaning roughly a cave with a stone tomb in it (or, Cave of the Stone Sepulcher). We crossed a river several times and then had to swim into the cave—the water was too deep to wade. After winding through several half-submerged crevasses, we climbed up a steep “cliff” of rock and were asked to remove our water shoes. The reason for this was that people without shoes on are more careful about where they step.

We saw increasing levels of Mayan artifacts after that point, which were sacrifices they made primarily to the rain god. The age of these artifacts was from 700 to 900 AD. First, there were pot shards, then whole pots (they would puncture a hole in them to make sure they would not be taken and reused). After that, we saw a bowl of a type used for bloodletting ceremonies, then finger bones, then a skull. Then the skull of a baby. Then, finally, in the last chamber we entered, we found an entire skeleton that looked as though it had fallen into position.

The escalating sacrifices may have been caused by increasing levels of drought and hardship caused by increasing deforestation. The Maya turned to the rain god, and the way they knew to appease the god was to sacrifice. They raised the value of the sacrifice and would go deeper into the cave because the caves are considered to be closer to the underworld.

When we arrived at the Tropical Education Center, our intermediate stop between the Las Cuevas Research Station and Glover’s Reef, I immediately noticed the birds. There were a couple of flycatchers similar to the Social Flycatchers we saw at Las Cuevas nesting in a Caribbean Pine (Pinus caribbaea). One fo the nesting pair was sitting next to the nest, and the other in a nearby trumpet tree (Cecropia peltata). The pines are much more common here—the only one I remember from Las Cuevas was in the clearing, and may have been planted. The reason the pines are more common here is that we are in a different region here, the Pine Savannah. This is the same region we went through to get to Las Cuevas, where the savannah was burning in patches because it is still the end of the dry season.

We went on an evening tour of the zoo, and we each held a boa constrictor to pose for a picture. Then , we looked at the different animals in the zoo. While we were looking at the owls, trying to get a good picture through the wire mesh, there was a sound behind us of leaves crunching. Apparently I dismissed it, which is alarming, because when we turned around, Scott pointed out that the jaguar in the opposite cage had been stalking us! As it turned out, more likely it wanted to be fed, and on command it performed an obstacle course and then a series of somersaults each for the reward of a small piece of meat. The incredibly strong jaws of a jaguar can kill prey by crushing the skull!

Holding a boa constrictor
Zoo sign for Pacas


Ant Day

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


Day 5: Null Hypotheses and Spelunking Adventures

Today we started off by summarizing the results from our experiments yesterday about Cecropia and ant interactions. My group ended up with negative results. We didn’t find any evidence of young Cecropia mimicking other plants. We did notice some differences between juvenile and adult trees, such as red petioles (the stems of leaves) and slightly longer trichomes (the tiny hairs on plants). However, we weren’t able to conclusively determine that those differences had an adaptive role. One group tested the toughness of juvenile and adult leaves and found that juvenile leaves were tougher. This could be adaptive because it would make it more difficult for herbivores to eat the leaves. If the project was continued, it would be beneficial to see if herbivores preferred younger or older leaves.

We also were able to visit the cave at Las Cuevas. The cave was a part of Mayan ceremonies, and there is still evidence of their presence. There are pottery shards throughout the cave system and the cave is built up in some areas. Platforms were built near the entrance and some spaces between chambers were made to be narrower. The whole history behind the cave is extremely interesting. The caves also had some wildlife. We saw at least two species of bats, millipedes, and a species of scorpion with long legs and no tail. One of the best aspects about the cave was how undeveloped it was. I’m not used to visiting preserved caves that haven’t been commercialized. It was cool to feel like I was one of the first to visit the cave, even though many, many people have visited it before me.

Entering the cave
Entering (taking pictures of) the cave

My favorite trees today were the big trees that we commonly see around the Chiquibul. The cedar (Cedrela odorata) can be 20-30m tall. Right now it doesn’t have leaves, but it has some wooden seed pods that are still attached to the branches. The seed pods look like 5-petaled flowers – they’re very pretty. Another big tree is the ceiba (Ceiba pentandra). When it is mature, its bark is very smooth and it can reach 60-70m. It has been difficult for me to identify ceiba from their leaves because the trunks reach so high into the canopy.

Cedar seed pod

We only have two more full days at LCRS, so we’ll have to make them count!

An Ant’s Life (Day 4)

We began our first real experiments bright and early this morning on the cecropia, or trumpet tree, which is known for its mutualistic relationship with Azteca ants. The hollow tree tunk provides shelter for the ants, and, in exchange, the ants defend against herbivores vying for the cecropia’s lobe-shaped leaves. Though cecropia’s mutalism with ants is incredibly effective, young cecropia trees are not yet colonized. How, then, do these juvenile trees protect themselves from herbivory?

We hypothesized that young cecropia use chemical defenses (like toxins or pheromones) to deter herbivores. Our pilot experiment involved collecting generalist herbivores, such as grasshoppers, and offering them both adult and juvenile cecropia leaves. We may not have the technology for chemical analysis here, but we do have sophisticated pieces of equipment like Tupperware and a butterfly net. We’ll see tomorrow if the insects opt to consume one leaf over the other, or even die after ingesting a toxic leaf.

A mature leaf-cutter ant nest.

The day’s ant theme continued with an afternoon dedicated to the fascinating life history of leaf-cutter ants. We looked at three leaf-cutter ant nests ranging from 1 to 10+ years old, observing their intricate tunnel systems and foraging trails. I was most amazed by the anthropomorphic qualities of leaf-cutter ants; they essentially act as farmers by cultivating fungus for food. The afternoon’s primary goal was uncovering these fungus gardens, which can sustain colonies of millions of ants.

Our focus today made reptile sightings difficult, as snakes and lizards are unlikely to be found in the vicinity of a large ant’s nest. Though we walked many of the same trails as yesterday, I wasn’t able to spot any of the Sumichrast’s skinks found yesterday in the leaf litter. I actually found better luck indoors today, spotting another common house gecko (Hemidactylus frenatus) running along the walls of our classroom.

Day 4: Ant behavior and interactions

Today we looked at two species of ants, Azteca ants and leafcutter ants. Azteca ants are a genus of ants that have a symbiosis with Cecropia trees. The ants provide protection from herbivores and competitors for the trees, and the trees provide shelter and nutrition for the ants. We wanted to look at how the trees are able to thrive when they are juveniles and before an ant queen has colonized the tree. To do this, we split into groups and designed hypotheses for how the trees adapted. My group looked into whether juvenile Cecropia trees mimicked other plant species or characteristics through physical adaptations. Tomorrow each of the groups will summarize their data and come up with a conclusion. It will be interesting to see which of the groups has the most convincing argument.

Silhouette of a Cecropia tree
Close-up of palmate Cecropia leaves

During the second half of the day we examined the life cycle of a leafcutter ant nest. Queens can live more than 20 years, although workers usually do not live longer than a year. Some colonies can have around 5 million individuals. Additionally, a mature colony can be about equal to a cow, in both weight and volume of plant material processed in a year. While we’ve been at Las Cuevas, we’ve noticed a lot of leafcutter ant trails around the area. Today we learned that those trails are only made by colonies that have been established for around 10 years. Smaller nests aren’t able to create or maintain the trails.

Scott hard at work digging up an ant's nest
Scott hard at work digging up an ant’s nest
View into a fungal chanber
View into a fungal chamber. The ants collect leaves to feed the fungi that they farm

The most interesting tree that I observed today was a papaya tree. Originally we thought that the papaya tree was a Cecropia juvenile, but the details didn’t match. The tree had large palmate leaves, a very tall and skinny trunk, and smooth bark, which are characteristics similar to Cecropia. However, the leaves were more lobed than Cecropia leaves and the reproductive structure of the papaya was different. It would be interesting to know how related Cecropia and papaya are; the books that we have access to here didn’t have information on their relatedness. I also was able to identify a tree species that we saw at Caracol with green flowers. The tree was a Mosannona garwoodii. The flowers were very camouflaged and appeared slightly waxy. I haven’t seen the same tree yet here, but it could be around.

Palmate papaya leaves
Papaya leaves are similar to Cecropia leaves but more lobed
Mosannona garwoodii flower at Caracol

Tomorrow we have the opportunity to explore a cave in the region. I’m excited to see what life we’re able to find in the cave.