I am auditing a seminar on the fundamentals of complex adaptive systems* and the presentation today was by Bert Hölldobler, an entomologist and ant expert. The topic today was on the territoriality of three ant species, including one local species of harvester ants.
I am fascinated by social insects and have been since I was a boy. Spending about 6 or 7 years killing (primarily) termites and other social insects created even more interest and actually respect for them. So, last fall when I took a research techniques in animal behavior course, I elected to look at territorial behavior in Desert Harvester ants (Messor pergandei).
In part, it was a sample of convenience because I had multiple colonies in the fields surrounding the dorms. So, my initial exploration was actually spending an afternoon watching them and observing them occasionally fight amongst themselves. When the actual data collection started, I systematically introduced a number of workers near the entrances of other, distant colonies from within the roughly quarter-mile by quarter-mile area.
Oddly, they were suddenly peaceful.
Not a single ant attacked any newcomer. I thought--at first--it was the solvent in the paint I misted over the newcomers. So, I waited for an hour after the inititial 2 trials. Still no effect. I thought it might be contamination in the "test frame" I had made from a plastic container, so I washed it throuroughly with soap and water, ran water over it and manually scrubbed with clean paper towel.
Still no dice.
It made the statistics simple, but it still nags me why the same colonies that were agressively attacking some subset of ants the week before were suddenly pacifists. My desire to explore alternate hypotheses was quashed the next week as the weather chilled. I posited one potential explanation was the potential for inbreeding given the distance from ASU West's campus and the open desert miles away.
Then, today, I learned two things, both something I should have expected based on the theoretical background. First, colony identification is typically imprinted and not genetically driven as I had been led to expect. This meant there was little possibility those M. pergandei weren't telling each other apart because of genetic similarity.
The second thing I learned today was how dependent ant aggression--specifically in the other Harvester Ant species locally--depended on the patchiness and availability of food sources. This is something I knew in terms of primate ecology and somewhat in human ecology, but simply did not connect it to my situation in terms of timing. I likely elected to conduct my study at a time when the availability of food did not promote defensive behavior.
Ultimately, although I prefer looking at humans and would consider primates, I would like to explore the concept again.
* - For those not "up" on the terminology, in simple terms, a complex system is a combination of elements--typically considered agents--where the agents create an emergent or novel phenomena in combinations while following only simple rules. A complex system becomes adaptive when the system changes in response to experience and "learns".
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