Tag Archives: caves

Cave + Urine Experiment + Coral Snake = 4.3 miles.

I woke up to people commanding me to pee inside a tube. “50 mills in two tubes” they said. I beat everyone else’s pee in coloration, which I like to think may be indication I have the highest concentration of nitrogen in my urine. And that’s relevant because, Scott tells us, one of the crucial limiting nutrients of the the canopy in tropical rain forests. After about an hour of questions, discussion, and writing in our field notebooks, we narrowed in on what exactly this urine experiment was going to be.

General question: How does different levels of limiting nutrients, such as nitrogen, affect insect biodiversity.

Context: In nutrient-poor soils of the tropical rainforests, nitrogen is often a limiting factor of life. It is more limiting in the canopy.

Main Hypothesis: The species richness in urine traps of canopy will be higher than water traps of canopy. This differential is greater than the same type of differential found in the forest floor, suggesting that nitrogen is more of a limiting nutrient in the canopy than in the forest floor.

After 2 days, we will collect our traps and count the numbers of the insect species we have captured.
For more on our project, please check a later blog post, which will contain our findings.

Also, today I found a bee hive outside of the dining room, with many yellow-abdomen bees coming out. They had all the similar morphological traits of a bee I had on my taxon identification card, but these had white front feet. I will have to look through more identification literature to see which species this is.

EBIO 319 In front of Las Cuevas Cave

The other half of our daytime was dedicated to something that better resembled the night. Walking in complete darkness during our first cave exploration. Las Cuevas (spanish for ‘the caves’) caves, are unlit karst formations that resulted from acidic water cutting through limestone. After many years, a whole underground network of life has formed, including the fertilizing bats who power the cave ecosystem through their feces and the accidental venturers who decay inside after failing to find a way out. Guano, truly, is a a glorified name for bat shit. You know, when people say, “that’s some crazy bat shit”… Well, it turns out that a whole ecosystem inside of the Las Cuevas caves (and many other caves around wthe world) depend on guano, both those of bats, and those from crickets. Cave millipedes ingest and digest guano and without it would not be able to survive. I would like to say more, but the fact on the matter is that we do not konw enough. Life there has been unidentified to a large degree, comparable to the deep sea or even extraterrestial life.

Currently, many explorers in these caves are people who are daring and willing to take on the complete darkness and the scary unknowns that come with being in caves. We were told by Raphael, leader of the Friends of Conservation and Development (NGO in Belize), that “we know that each time someone goes into the cave they find a new species”. At the very least, someone ought to write a post-apocalyptic novel revolving around life in the caves. One of the last things we did in the caves was to use guano mud to write and draw on the cave wall. Having heard stories about the Mayan demise, it makes me wonder, when it comes to cave art, how much we, as a species, has evolved in leaving behind markers of our existence and what, if any, meaning can be derived from our symbolic representation after our species has either evolved or died out.

Day 4: Pee in Vials; Not in Caves!

Blog Post #4

Day 4: Pee in Vials, Not in Caves!

Written on May 19that 7:13 am


DISCLAIMER: Las Cuevas was supposed to have internet—right now, it isn’t working. All LCRS posts from the rainforest will be posted after the fact!

I didn’t write this blog post last night because I was just so, so tired! I fell asleep with the lights on (3rdnight in a row) with lots of people chattering around me.

Anyways, we started the day with birding—we tracked the beautiful scarlet macaw mated pair as they chattered away. During this time, Scott handed us 2 50 mL vials and told us to fill each with 25 mL of urine. It was a very odd way to start the day, but turns out, our second project had to do with nitrogen scarcity and insect diversity in the canopy vs the forest floor.

Once we developed our question, hypotheses, null hypotheses, and methods, we set out to bury and hang out samples along with water vial controls. We picked two different sections of the same trail and placed them roughly 100 ft apart. We’ll collect them after two days to analyze what kinds of bugs fell into our pitfall traps! During our hike, Sam did spot a red-banded coral snake under a log and we got to watch it slither away.

In the afternoon, we had the special opportunity to spelunk into the Las Cuevas Cave, just a mere 100 yards away from our clearing. It was beautiful!! The stalactites and stalagmites glistened, glittered, and shined with all kinds of minerals. Since the cave has technically been closed for archaeological excavation research, it was relatively untouched and purely natural. Biologically speaking, we saw a bunch (literally) of baby bats (see pic), adult bats, crabs, isopods, mites, and an amblypygid (a glorified spider), and a peccary skeleton. Mayan wise, there was a nearly intact bowl, a metate (grinding stone), faces carved into the rock (rudimentary, but very noticeable), bone fragments from human sacrifices, and lots of shattered pieces of pottery. It was really incredible to walk the same walk and see the same sights as the kings or high priests of the Maya culture did when they worshipped in this cave to their rain god Chaac.

In the evening, we had our lectures, and a somewhat rare amphibian sighting! There was a frog in the window, and I caught/held it (see pic). I’m unsure of what kind of frog this was, but when we reach internet, I’ll for sure look it up! (UPDATE: It was a Mexican Tree Frog without its coloring since it was night time)

(Hey Mom and Dad, do I look happy? :D)

Day 5: Cave Mysteries

Today was a bit low on cockroaches, mostly because our group was out busily setting up our pitfall traps. We wanted to analyze differences in nitrogen limitations (AKA organisms desire for nitrogen compounds) between creatures that live high in the forest canopy and those that live on the ground since distribution of nutrients is different in those locations. These traps held nitrogen bait (human urine!) and served to trap insects within. One trap was set onto a tree and another on the ground. Maybe this will be a good chance to see a few roaches!

Most of the roaches that I have found in Belize were often under a pile of leaves, feeding on decaying matter. The advantages of such a bottom-dweller lifestyle is double edged. Dead materials are not usually heavily competed for due to abundance of microbes and leaf litter provides excellent protection from predators and aspiring entomologists like myself. Perhaps in light of this, I can predict that if the traps can fit roaches, then I should find more roaches in the ground traps than in the tree traps. But whether their contribution to our question on differences in nitrogen limitations of the canopy and the ground will matter is up in the air until tomorrow when we retrieve our traps. Before then, I can only guess.

A roach was sighted during a noon leisure excursion to one of the Las Cuevas trails. It was tiny, wingless and fast moving. I tried to snap a photo, but it managed to hide a part of its body behind one of the spines of a give and take palm. Better than nothing I guess! I could improve my roach findings by perhaps searching during one of our night hikes!

Other than trap setups, our team visited a cave near where we lived, learning about the caves history and use by the ancient Mayan societies as a ceremonial ritual between their chief and the nine realms of the underworld that each section of the cave represented. In spite of the uneven terrain and low oxygen levels, I was captured by the mystery surrounding the cave structures and biological life! We spotted bats, tiny insects like diplurans, isopods, crickets, and even large millipedes, and learned how these creatures were sustained by cave nutrition. This may come in the form of droppings by bats or by nutrients entering the cave. No roaches, so bummer for me, but exciting nevertheless to explore one of the mysterious habitats of the earth!

Into the cave we go!
Into the cave we go!

P.S: speaking of mysteries, we found a peccary skeleton in a tiny chamber of a cave. I wonder how it got there? Did it wander through the pitch-black cave and get lost, or was it brought in as sacrifice by an ancient tribe.


Day 5: MAMMALS!!

Today was the best day at Las Cuevas thus far. In comparison to most other days, I saw many mammals today of various new species. The most exciting viewing occurred at the very beginning of the day, during an early morning walk in the forest. As I neared the entrance to the research station clearing, a tayra (type of weasel) walked across the path about 15 to 20 meters ahead. The tayra looked very typical, with a dark brown body, paler head, and yellowish chest patch. Upon seeing me, the animal raised its tail and began to growl softly. After taking a few steps forward, it calmly decided that I was not worth its time and walked off into the forest. Amazing!

Tayra captured as it walks back into the forest cover
Tayra captured as it walks back into the forest cover

We had a few other mammal encounters today. As has occurred the last few days, we heard Mexican black howler monkeys from the research station. Today, the howling was more frequent and louder. I’m hoping that this means that we can actually find them in the forest soon.

Additionally, we saw two species of bats when we visited the Las Cuevas caves. The nine-chamber system used to be an ancient Mayan ritual site, as can be seen by the built structures and pottery sherds (sherds for pottery, shards for glass, as I learned today). While crawling through the caves, we came across a small group of wrinkle-faced bats roosting in the cave ceiling. In another chamber, we saw a larger group of what were likely gray fruit bats hanging upside down from the ceiling. The high-pitched sounds made by these animals was really cool to experience.

Gray fruit bats with distinctive noseleaves
Gray fruit bats with distinctive noseleaves

We also started another project today that we will conclude tomorrow. We set up vials of urine (produced locally) and water (as a control) as pit-fall traps for insects and other arthropods. We put half of these in trees and half in the ground to test whether tree species are more attracted to the nitrogen-rich urine due to nitrogen limitation in the canopy. Hopefully we’ll catch some cool creatures overnight!

Finally, one of tonight’s lectures was given by Boris Arevalo, a biologist for Friends for Conservation and Development. He discussed the various challenges and opportunities associated with the Chiquibul forest, and how conservation involves an understanding of social, political, and ecological issues. I found this very fascinating, especially as he discussed the delicate situation between Guatemala and Belize at the border. I look forward to hearing more from other researchers here at the station tomorrow!

The Art of Spelunking (Day 5)

I never truly appreciated the feeling of being clean until today. There’s one thing about coming back hot and sweaty after a hike, but it’s quite a different feeling returning from an afternoon of spelunking covered in a fine mixture of mud and bat guano.

View from inside Las Cuevas cave.
Wrinkle-faced bat inside Las Cuevas cave.

But let’s backtrack. Today’s tasks began relatively lightly by wrapping up our (inconclusive) cecropia experiments. The day’s primary activity was the exploration of the cave from which Las Cuevas gets its name (and water). The 9-chambered cave is the center of an ancient Mayan ceremonial site, with each of the rooms representing one of the nine layers of the Mayan underworld. The cave holds numerous Mayan structures and pottery, and even what appeared to be a human femur. I doubt I’ll be picking up spelunking for recreation anytime soon, but our exploration gave me a newfound appreciation for cave biology. We found two species of bats within the cave system, as we crawled on hands and knees through narrow passageways that opened into large caverns. I thought I was clean until the cave’s final test: a tiny chamber with low oxygen content, housing a peccary skeleton. Let’s just say I was in great need of a hot bath after that adventure.

Finally, we set up an experiment to test nitrogen deficiency in arthropods of the rainforest canopy. Once again, we utilized extremely sophisticated technologies to create pitfall traps for arthropods in the canopy and forest floor, taking advantage of our most accessible nitrogen source: urine. I was thankfully spared from urine collection, but the afternoon was dedicated to setting up pitfall traps along the Maya trail (not named after yours truly). Though there were no sightings today, the leaf-litter our traps were set in are a prime habitat for venomous snakes; the forest floor was thoroughly checked for species like the yellow-jawed tommygoff (Bothrops asper) before setting traps. I did however spot several anole species along the Maya trail, all of which moved too quickly to be identified.

All in all, day 5 of EBIO 319 is best summed up by the following statement by Dr. Scott Solomon, “We’re exploring the mammalian excretory system!”

Day 5: Look, a hole in the ground. Let’s go inside it.


Today we hung vials of our urine on trees and went to the Las Cuevas Cave. It was so sublime. Get it? Sub-lime… stone. Sub limestone. Like going under the limestone, you know? Into a cave and stuff. Doing cave stuff like crawling through mud and bat poop.

I discovered an interesting biological phenomenon. There is a very blatant negative correlation between my fatigue level and my mental capacity. I sincerely apologise for the poor English and abysmal humour I’m subjecting you to. Although who am I kidding. Is anyone even reading this? Hi Scott and Adrienne, thanks for reading.


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.


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


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.



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.