A battle for the desert

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Pogonomyrmex maricopa (at left) tussles with an Aphaenogaster albisetosa at the Aphaenogaster nest entrance.

While in Arizona, I chanced upon a set of ant fights that I'd observed several times previously.  Single workers of the maricopa harvester ant Pogonomyrmex maricopa would approach a nest of their competitor, Aphaenogaster long-legged ants, and spend a few minutes drawing heat from the guards before wandering off.

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Same thing, but different individuals (note differences in limb wounds from the previous photo)

The interaction is common enough that it really couldn't be just a chance encounter.  Are the Pogos doing this for a reason?  Are they distracting the Aphaenogaster from foraging?  And, are there any myrmecology students in Arizona who need a little research project? It'd be great to figure out the purpose of the fights.

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Three on one.  Do the Pogos subject themselves to this treatment as a decoy, to draw Aphaenogaster away from shared foraging territory?

photo details (all photos): Canon mp-e 65mm 1-5x macro lens on a Canon EOS 50D

ISO 100, f/13, 1/250 sec, twin flash diffused through tracing paper

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Interesting observations and great action shots! If these competing ants are active for the same parts of the day, I wonder if the Pogos are scouting out rival colonies' activity at certain times? Would make an interesting little project, that's for sure.

whow, these are the action shots that make a heart thumb faster. Very sweet observation and nicely caught onto the digital film.

Couldn't the behaviour be like testing "the lines" ? Like if there is little resistance, it's good to attack, else back off ? I thought there were a few insectspecies around that use that tactic.