Home ---> Notes ---> article

(en español)

A Yucatan experiment: Atta soldiers as bulldozers of the colony?

- by Dr. A. Buschinger

During our vacations in Yucatan, in March 2004, I made a couple of observations and small experiments. On the access road to Kohunlich the Atta trail is much cleaner than our hiking trail!

The remains of a rose bush in front of our cabin, after the ants had directed a trail into the village of Frontera Corozal, starting point for boat trips to the ruins of Yaxchilán. Children on the way to the river there preferred to walk on the Atta trails instead of going through the lawn or leaf litter. They were barefooted, and went swimming in the Usumacinto in spite of crocodiles living there (they were said to feast on tourists only ...).

It was on 3/14/2004 at Frontera Corozal, in the strip of forest above the boats. Having seen a couple of majors engaged in removing obstacles from the trail, I wondered whether there would be a special recruitment of soldiers to a really hard and big obstacle. I chose a place some 10 m from the nest. Within 10 min I counted six soldiers coming from, and two running towards the nest. They ran with higher speed than all other workers, cutters and carriers.

I pushed my pocket knife into the trail.

The traffic was slightly hampered, but soon a soldier appeared and antennated the handle.

Then it tried to drag out the blade from the soil!

No recruitment of further majors could be observed within about 1/2 hour. So I decided to make another "experiment": What happens to a "soft" barrier? - I cut a slit into the soil and put a piece of paper into it, closing all the trail. Quickly, a traffic jam developped. Carriers with young leaves assembled in front of the paper, and workers coming from the nest, on the other side. One or two majors appeared, antennated the paper, and went away. But a few cutters climbed the paper and began to cut out pieces - with some success!

Meantime a major began to clear a detour trail.

It was evening, quickly growing dark, and a sudden heavy rainfall stopped my activities. So I could not see what happened later. The next morning the paper had disappeared (though perhaps one of the children who watched us during all the experiments may have taken it away), and the trail was perfectly smooth and free of any obstacles. Of coures, these few experiments are everything else but a scientific study, but I got the impression that the so-called soldiers (or majors) have a particular function in removing strong and heavy obstacles from the trail, at least in addition to their defensive function.

I should add that my first intention was to use a 20 peso bill instead of the paper sheet, to symbolize how excessive road construction consumes money . However, the children around us certainly would never have understood why this crazy tourist feeds money to the ants. - Fortunately my wife could at least explain to them what I was doing there. I am afraid that otherwise I would have ended up in jail or in a loony-bin!

Return to previous page

Web Site Author: A. Sunjian
Site Created 2003.10.11
Site Dedication