Pheidole obtusospinosa
● Madera Canyon (Whitehouse Picnic Area), AZ [el. 1364 m / 4474 ft] view location in Google Maps » ● 11/05/2010 9:36AM sunny, windy, air temp: 22°C / 71°F
[IMAGE 9 of 9 - see notes below for background info on this series of Pheidole obtusospinosa images] Here is the battle in its final stages. The intruding supermajor (at center) can be seen with a gaping hole in her head capsule, while still being held from below by a home supermajor, and attacked by another. Finally, the defenders removed the intruder's head entirely, and one of them dragged it toward the nest entrance, and started pulling it inside. At that point, all of the ’home’ majors and supermajors quickly returned to the nest interior, leaving only a few foraging minors to be seen. About 1.5 feet away, a major (apparently from the intruder's nest) ran around crazily for a few minutes, then disappeared into the leaf litter, presumably returning to the interior of her own nest. For the purposes of these images, I refer to the colony that is being attack (or intruded upon) as the 'home' colony. [scroll down for additional notes/references]
ADDITIONAL NOTES/REFERENCES:
These Pheidole battles were observed on 11/3/2010 and 11/5/2010. In both cases, it appeared that workers of a nearby Pheidole obtusospinosa nest attacked, or simply wandered into the nest area of another colony of the same species. All three types of workers (minor, major and supermajor) were seen engaging in defense of the colonies, though the supermajors inflicted the most damage. In both cases, I was not able to find the exact locations of the nests where the intruders came from.
These images were captured in Madera Canyon (border of Pima and Santa Cruz counties), in the Santa Rita Mountains of southern Arizona. The elevation was measured at 1364 m / 4474 ft. The ants were found in a juniper/oak woodland area, and were in partial shade. Air temperatures ranged from 21°C/70°F to 23°C/74°F. Two nests were seen. One of these had a small, irregular spread of fine sand and gravel around a single entrance (entrance approx. 8mm wide). The entrance of the other observed nest was hidden somewhere in a tangle of twigs, leaves, and other debris. Both of these nests were located immediately adjacent to a paved walkway. These battles took place amongst a profusion of twigs and leaves, so much of this action was very difficult to capture photographically. I did my best under the circumstances…
