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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.

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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.

Cave… More Like Rave

Today we went into Las Cuevas Cave, which is Spanish means “The Caves Cave.” Cool, but not exactly creative.

Here’s the whole TFB squad with our snazzy headlamps on. This is around when the electronic music began and we all started raving.

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This was the first totally dark cave system I have ever explored. The sights and sounds were foreign to say the least.

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The entrance to the cave was the only place all day where there was any penetration of natural light. Here cave swifts (birds) hunted for insects in what looked like the most fun method of hunting I have seen here in Belize. They flapped their wings vigorously for a few seconds and then dove down only to catch themselves midair when they ate a bug and repeat the cycle. Fun.

In the cave, life takes on strange forms. With little to no light the organisms here have evolved to survive without seeing much, instead feeling around with their long, slender limbs. For example, we have the cave cricket (pictured here) from the family Raphidophoridae is a bizarre take on the classic cricket. It has a humped back and long antenna for searching the cave in low light conditions. Creepy.

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What Goes In Must Come Out

Entrance to Las Cuevas
Entrance to Las Cuevas

I had so much fun today setting up pitfall traps and visiting the caves that give Las Cuevas its name.

In the morning we learned about nitrogen limitation in the canopy, and how most decaying matter falls to the forest floor. This lead us to hypothesize the animals in the canopy would be more attracted to a nitrogen source than animals on the forest floor. We used our own urine as the nitrogen bait for arthropods in the canopy and on the forest floor in our pitfall traps.

Later in the day we visited Las Cuevas (the actual caves), which was an amazing experience. I got to see some Mayan pottery, a peccary skeleton, and a long bone of a human skeleton.

Cave formations
Cave formations
Adrienne goes insane over pottery
Adrienne goes insane over pottery

In the caves I got covered in bat guano and actually saw the bats it came from. They may or may not have been vampire bats, but that was not confirmed. We definitely saw some species of leaf nose bat.


Arachnids were very exciting in the cave. I got to see the whip scorpion today, which is my new favorite species. I will have pictures to come of that. We saw the large darker colored whip scorpions and also the very light colored (white) tiny whip scorpions. I also got to see a cave spider.

Whip scorpion
Whip scorpion

After our hike Pedro (who works at the camp) found a very tiny tarantula on his shoulder. He says he thinks its a cave species because he’s never seen it before. I took detailed pictures of its eyes, back, and legs. Sophia and I are gonna call it the Little Boots Scorpion (Sophia claricus) if it is a new species.

Cave tarantula (new species?)
Cave tarantula (new species?)

We heard a fabulous talk by Boris Arevalo (the head biologist at FCD, which manages the Chiquibul). He talked about the limitations of conservation and the opportunities the Chiquibul presents.

Bold Choices With Ants

Wow are my feet sore from yesterday. These blisters aren’t helping either, but we had an incredibly fun day learning about ant symbioses.

First we tested hypotheses about how the young cecropera (trumpet) trees avoid herbivory before their symbiont azteca ants colonize them. Our hypotheses ranged from chemical defense to mimicry. My group tested mimicry, which is almost certainly not how they avoid herbivory due to their very similar leaf characteristics to the adult plant.

Later in the day we looked at the development of leaf cutter ant colonies, and the fungi they farm. We dug into a 1 year old nest, a 3-5 year old nest, and a 10+ year old nest, and looked at the difference in which castes are present in the nest and how big their tunnel systems are.

The 10+ year nest was huge and there were soldiers coming out of it in swarms trying to bite us. I was incredibly glad for the rubber boots at that moment, although I still got a bite from a soldier on my finger as I was taking an ant off of Scott.

I didn’t see very many arachnids today because we were mostly focusing on looking for ants and ant nests. I will look for some tomorrow at night when we can see their eyeshine.

Day 5: Staying hydrated

In the spirit of a true field course, today we set pit fall traps with our own urine. We are trying to test the differences in needs for nitrogen in Arthropods based on forest layers. We didn’t do too much hiking today, but I guess today was a bit more taxing on our mental strength than our physical.

Wrapping up our herbivory preference trials from yesterday, we found inconclusive results in terms of the presence of chemical defense in young Cecropia trees. This result was fairly expected based upon the small sample size, but in some cases I was a bit shocked. Six of the eight herbivores used(one caterpillar, one beetle, six orthoptera) did not consume any foliage. I had expected to see more bite marks on the leaves I suppose.

While we did not hike much today [so not many Lepidoptera sighting chances], I did still see Lepidoptera. When we went on the trail around the archeological sites at the research station to set our pit fall traps, I saw some butterfly. I mostly saw small brush-footed. I keep seeing one that’s about 6 cm in wingspan and it white with black markings and I am just not completely sure which it is. A classmate who is particularly skilled with the butterfly net managed to catch one of the fast flying teal and black swallowtails. I did not try with the net today but I managed to catch a moth in my room last night. It is  not listed in the additional field guide I have so I am not sure what it was. About 2 cm in wingspan, it was yellow and brown to the point it was almost colorful.

Tomorrow we will have to collect the traps, but we will also get to hear another guest lecture from one of the researchers at the station. We heard a presentation tonight focused on the area that we are staying in. I’m glad we are getting to learn more about the Chiquibul forest and I feel I’m starting to feel a bit more at ease with the constant animal and forest noises I don’t usually hear in the city.

Day 4: Staying Over at the Ant’s Place

Today was just another day in the field. We were investigating the interactions between two different species of ants with their respective environments, Cecroppia trees and the Azteca ants, and leaf cutter ants (Atta cephalotes). I didn’t really expect to see any roaches today, since the only roaches I knew that had some affiliation with ants are of the genus Attaphila, meaning ant loving. These guys are about 2-5 millimeters long and can often be seen hitching a ride on flying queen ants, which emerge right before the first rains in Belize. As we are coming in right at the end of the dry season, it may be possible to find these Attaphila, but I doubted whether we could spot a creature as small as a few millimeters in the midst of a giant ant nest.

One of our activities involved digging up leaf cutter ant nests to find their fungus chambers (see below!). During one of the digs, one of my colleagues spotted an inch long roach like creature in the midst of the angered ants. It appeared to have been actually living in the nest, a characteristic of Attaphila! Unfortunately we accidentally lost the roach as we were unable to stop digging, but after some in depth roach profiling with my colleague I learned that the creature was an inch long, lacking wings, shiny, and quite oval shaped (1 inch length, .5 inch width). This was clearly longer than any other Attaphila I had heard described in Belize or in other parts of the world. It may even be possible that this is a different ant loving (myrmecophile) species altogether. But without a picture I can’t verify, so hopefully I may be able to find another one during our activities!

A small sample of underground fungus farmed by leaf cutter ant (Atta cephalotes)
A small sample of underground fungus farmed by leaf cutter ant (Atta cephalotes)

Day 3: Bold Choices

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Today was our first day of actual fieldwork!  We wanted to study how species richness and composition vary in natural and man-made clearings, so we marked out 12 locations on the map.  The hike looked completely manageable when mapped out on the whiteboard, but the elevation was a little more than we anticipated.  13 miles, 31,000 steps, and 10 hours later, we had placed our traps. We put 6 camera traps on roads, trails, and human-frequented clearings.  In addition, we put 6 traps in natural clearings such as tree fall gaps, streams, and massive leafcutter ant nests.

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We saw 3 termite nests today, but still no termites.  The first was an arboreal nest approximately 1 m off the ground, but it was very far off the ground.  We also found a carton mound approximately 50 cm tall.  Although the mound was empty, it resembled a Rotunditermes bragantinus mound.  Likewise, we found an empty clay mound 20 cm tall, which could have belonged to Embiratermes neotenicus.  In addition, I found a tree that had died, but was still standing.  The heartwood was filled with insect tunnels reminiscent of Coptotermes formosanus damage. I have not been this tired in a very long time, but we saw and heard lots of amazing wildlife and it was definitely worth the hike.

Day 4: Why we wear rain boots.

Today was ant day. In the morning we set up some Tupperware boxes with leaves and different herbivores- a caterpillar, an odd beetle (?), and six orthoptera. The leaves are from Cecropia or trumpet trees and are usually filled with Azteca ants-unless they are quite young. So we are trying to see differences in the herbivory on mature Trumpet trees that have ants already and the young that do not, results that could be indicative of some sort of chemical defense in the young trees lacking the defense provided by ants. So of course we went out into the field. We were tasked with collecting the leaves and herbivorous generalists we would use in our set up. Trumpet trees tend to grow in disrupted areas such as roads. We therefore began walking down the road.

While searching for our materials we saw lots of insects, including Lepidoptera. We saw army ant soldiers that have huge mandibles. I also saw a lot of Blue Morpho butterflies. It seemed right when I let my guard down one would fly by quickly, always evading my net. I also saw another heliconia and realized I had misidentified the one I saw yesterday. Along the road side one kept fluttering in and out of the brush. The one yesterday and the one today were both “postman butterflies” or Heliconius melpomene rosina. And the Blue Morpho continued to tease me. A small satyr-looking butterfly landed on someones hand also.

In the afternoon, we excavated leaf-cutter ant nests. The last one was down one of the trails a bit and is over ten years old. There are millions of ants in the single nest and a good deal of them went into a frenzy when we began digging. The ants can pinch through skin and made a couple people bleed. They can also cut through shoe laces…hence why we wear rain boots. Around dusk, walking back to the station, I saw one of the most impressive butterflies. The Owl butterfly can grow over 7 inches in wingspan and one landed in front of me on the trail. I saw the closed wings, so its gorgeous eyespots were visible.

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Successful net catches today = 2 butterflies. I have a very low success rate, but I am improving.

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.

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Silhouette of a Cecropia tree
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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
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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.

Some privacy please…

Unbelievable encounter today—I witnessed two giant katydids mating near a massive leaf cutter ant nest. The amorous pair fled to the safety of a tree where I shot this photo of them.

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These two, and the third of the same general appearance (who I assume was the lookout) were highly camouflaged and had large spines on their hind legs.

This all occurred while we were digging out the leaf cutter ant nest in search of their fungus garden. These highly complex social insects spend all day collecting foliage, which they use to feed not the ants, but their fungus garden, which in turn is the ants’ only source of food.

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In order to cut up the foliage into ant sized pieces the animals have large, sharp mandibles for slicing. But it’s not just leaves that they slice with these formidable jaws, but also young biologists! After being nibbled on by a minor worker (these insects have a caste system based on body and specifically head size—the minors are the smallest of these castes) I thought these ants were chumps. Then the major workers had a much easier time cutting through callouses on my hands. The soldiers however (pictured here), were truly tough, drawing blood from my fingers with their bites. Luckily no stings, however, so the pain was manageable.

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