Harvester Ants and Mesquite Seeds

On a recent trip to the Hassayampa River Preserve, we ran across a number of harvester ant mounds, particularly those of Pogonomyrmex barbatus.

I examined the refuse piles, or middens, to see what the ants had been gathering.

Pogonomyrmex barbatus typically gather seeds and their middens reflect that.

The larger ovoid seeds caught my eye, because I knew what those were from.

The Hassayampa preserve has numerous mesquite trees of various kinds.

The trees were covered with seed pods.

More mesquite pods covered the ground under the trees.

If you look closely, the pods consist of strings of seeds embedded in a starchy, sweet material that is sometimes ground up and used for flour. Having tried grinding up the pods before, I knew they are fairly tough.

Somehow the harvester ants were finding partially processed seeds with the starchy pod removed.

It seemed doubtful they were processing the pods themselves, at least I saw no evidence they were when I looked at the piles of pods under trees. Time to look around some more.

That’s when I found a big. smelly clue.

Ah, now that makes more sense.

My best guess is that the scat comes from a coyote. In the Sonoran Desert coyotes consume a lot of mesquite pods. Apparently they digest the pods but leave the seeds “behind.”

Have you ever seen harvester ants scavenging seeds from scat? Do you know what kind?

2 Replies to “Harvester Ants and Mesquite Seeds”

  1. I have an ant farm that consists of harvester ants. Unfortunately I have not been able to see them scavenge seeds but I have seen them “cutting” the gel in my ant farm with their powerful pinchers, ( or is it their jaws? )

  2. The mouthparts are called mandibles, although they could be called jaws.

    The gel habitat was designed to serve as food, water and housing for the project that sent ants into space, and therefore was meant to be short term.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.