First Place - YouTube Your Entomology Contest

The Entomological Society of America holds a wonderful YouTube contest at their annual conference. For this year's contest, I submitted the video that Andrew Quitmeyer and I made about the general magic that is the Azteca-Cecropia mutualism - and we received first place! I give most of the credit to the level 10 charisma of the system and the amazing Quitmeyer. Watch the other superb video finalists here.

Forest of the Glowing Symbionts

As a form of creative expression, experiencing my data in a different way, and relaying my scientific narrative with the public and other scientists, I have created the Forest of the Glowing Symbionts. These glowing tree sculptures represent specific Cecropia trees and their Azteca colonies from my collective personality field experiment. The timing of the blinking in each scaled tree is synced with real ant patrolling data from different colonies. When shaken, the lights ignite just as the colony did, with a data-based spurt of increased activity. By observing the trees' blinking patterns and how they respond to vibration, you can get a sense of the colonies' personality. 

What about sloths?

A three-toed sloth attempting to reach the Cecropia leaves.

Being deterred from a mature Cecropia tree.

Scratching at Azteca ants.

The best way to see a sloth in the tropics is to scan large Cecropia trees, looking for a still, amorphous lump. The common knowledge is that they spend most of their time in Cecropia trees, preferring their leaves. But do they? It may be just a simple observation bias given that the minimal, elegant structure of the tree provides the best chance to spot something that doesn't fit. Either way, what I'm really interested in is their interaction with Azteca ants. Do ants somehow ignore these slow moving beasts? Or do the sloths ignore the potential onslaught? Or perhaps colonies differ in their response to sloths. I've gathered minimal anecdotal evidence for any of these ideas because it's hard to get up close to observe whats happening. I have seen sloths get deterred from a tree before they even reach the leaves, and I've seen sloths eating at their leisure. Perhaps it is the sloths that vary in boldness or pain tolerance. Experiment planning is underway.

A three-toed sloth foraging leisurely in a Cecropia tree.

Howler monkeys attack!

Howlers often drop the leaves after they've chewed off the petiole.

These howler monkeys have very different foraging approaches depending on which Cecropia tree they are feeding on. In the first shot, the monkey seems to be minimizing its contact with the plant by reaching out from a another tree, retreats quickly after snapping off the soft meristem, and presumably scratches off the attacking Azteca ants. In the second shot, the money is chomping at its leisure, lounging on the Cecropia tree itself. Perhaps these monkeys are being met with differing levels of aggression by the resident Azteca guardians . . . 

Young colonies, wild saplings, explosive responses

So far, I've been focusing on medium-aged colonies in medium-sized tree for standardization reasons. In a recent experiment conducted with Karla Moeller, we expanded our sampling to include young saplings and old giants. Here's a sneak peak at how one of our sapling colonies responded to leaf damage. Note that as the ant that discovered the damage returns to the stem to rally her nestmates, she is dragging her abdomen, laying a guiding chemical trail.

The Greenhouse Harvest

Photo: Barrett Klein

One year ago, the great harvest took place. Harvest time is always an exciting, bittersweet scramble. I've been studying these colonies for these colonies for two years - discovering them in the field, getting to know their personalities, extracting them and implanting them into my greenhouse, watching them recover and grow, and studying their change in behavior, if any. Now to answer many fascinating questions about colony growth, morphology, plant investment, nutrient flow, and microbe communities, the colonies and plants must be sacrificed. With 42 plants, half of them hosting colonies, timely processing is an incredible feat - impossible for one person. It was at this time that I called on the other scientists at the Gamboa field site to volunteer their spare time to help with the harvest. I was overwhelmed with support, and together, we pulled it off. Sample analysis and behavioral scoring is underway. I could not have done this without you Sebastian Stockmaier, Agustin Diaz, Megan Pendred, Eloïse Lebrun, Yussef Castillo, May Dixon, Claire Hemingway, Krzysztof Kozak, Aaron Goodman, Eva Gril, Clément Aubert, Lynette Strickland, Barrett Klein, and Brendan Dula. Any time you need a helping hand, I'll be there. 

Photo: Barrett Klein

Phase III Behavioral Reassessment Complete

All of the transplanted greenhouse colonies have been thoroughly reassessed on their patrolling behavior and responses to vibrational disturbance, leafcutter intruders, army ant intruders, and leaf damage. A terabyte of videos await analysis, so stay tuned for the colony comparisons of how much they've changed since the transplant last year and if their behavior was affected by their host plant's soil nutrients.

Watch a patroller recruit to leaf damage

Patrolling Azteca ants that discover freshly damaged leaf material recruit their nestmates to the damaged site to fend off any offenders (or even make a meal of them if they can). This robust, fascinating behavior is one of my favorites to watch unfold. However, it is very difficult to film this interaction in its entirety because tracking such small, fast individuals while maintaining a decent focus takes practice and luck. Recently, I was lucky enough to follow the discoverer from the damage site, along the leaf vein to the petiole junction, all the way across the petiole to the main stem, and back. If you look closely you can see her dragging her abdomen as she runs to lay a pheromone trail that her nestmates follow. She also seems to release an alarm pheromone at the leaf-petiole junction that activates all the poised workers waiting there.