There are ants everywhere. Everywhere. Ants. This in it of itself is not an unusual thing as ants are arguably the most ecologically successful group of organisms on the planet. Most places on earth have a respectable ant fauna, particularly containing those found in association with humans (looking at you Tapinoma sessile). Yet since coming here I have been quite taken at the diversity of ant species and the equally diverse ways they make their living. Below are a few of these neat six legged ladies I’ve met so far.
Leafcutter ants – Atta cephalotes
If you have seen a row of leaves moving through the forest, it was likely due to these ants, who harvest leaves to feed to their fungus garden. I found several colonies on BCI, one which had several nests (they are polydomous, and single colony will inhabit several nests) right next to the cafeteria. Them seem to only harvest young tender leaves which given their lack of physical defenses would be easiest for them to cut.
Atta are perfect examples of morphological variation among the worker castes. Among the sterile female workers there are several different size of workers produced. The largest workers (called majors) have exaggerated heads which can assist in their job of carrying leaves back to the colony. While ~15% of ant species have this variation (often called polymorphism) it is unclear why some species have them and others don’t.
Bullet ants – Paraponera clavata
When we were walking down to the canopy crane a giant ant walked across the stairs. I have heard tale of the fearsome bullet ant, and yet in person it was quite adorable with long antenna and a slender figure. This was a lone worker probably foraging for live insect prey but individuals frequent the canopy to also forage for nectar. Its common name comes from their fearsome sting it has one of the highest ratings on the Schmidt pain index. There is a great description of the sensation by Alex Wild here. I am really excited to find a colony and if I happen to be stung, so be it in the name of science.
Army ants – Eciton burchellii
This colony of army ants we found on pipeline road is one of several ant lineages to independently evolve the so called legionnaire syndrome (nomadic lifestyle, raiding swarms etc). They form bivouacs, temporary nests and then make raiding swarms to capture arthropods and even some small vertebrates. I was super excited to see them for many reasons, but especially for their amazing soldier caste. They have large exaggerated mandibles that are thought to be a defense against any foolish vertebrates to cross them. So large are their jaws that they must be feed by their smaller sisters!