In late October I came across an industrious group of
Harvester Ants. These ants of the genus
Pheidole exhibit dimorphism, having two different sizes of workers; a smaller
size dedicated to food gathering and general nest chores along with a larger
version that uses its extremely large head in defense of the colony. They are
primarily seed gatherers and were busy moving spent flowers into their nest. I assume there were some edible seeds
included with the flowers.
The ants had located their nest in a shallow mound of bare
soil. The plants in the upper right of
the photo are Draba cuneifolia, a rare winter annual. I’ll be checking this plant population later
in the year, so I’ll take some time then to see if I can identify these ants to
species.
As usual, I was behind on the amount of work I had hoped to
accomplish for the day, so I only took the time to get a couple of still shots
and a short video. The huge headed
individuals seemed to be constantly on the move. My presence may have disturbed their normal
behavior, but I didn’t notice them until I was almost on top of the nest, so I
don’t know what they were up to a few seconds earlier.
Interesting. They looking incredibly different from the two species of Harvester Ants I know in San Diego County when growing up. There are two, one Red Ants and the other Black Harvester Ants. The Black are much bigger than the reds and more agreesive in that they mow down all vegetation materials in the building of various highways to food sources from the main entrance of their nests. The Red never do that. In both they are all the same size, probably about the size of your big ones there.
ReplyDeleteNot sure if it's the same, but try photographing when you are down wind of the Ants. If you are upwind they will aggressively come towards you are the moecules in the air they some how detect and become aggitated. Just an idea, you can test it out.
Thanks for the pics and video.
Hi, Kevin. In general, most California species are a different genera than those species found here in southern Ohio, so there's bound to be some behavioral differences. I think the red California harvester ant is the same species that came with an ant farm I received as a kid back in the 60's.
DeleteSince ants rely a lot on chemical communication, it makes sense that some species could be sensitive to odors produced by potential predators. I'll see what happens the next time I run into this species.