Tag Archives: Arlington Texas

Comanche Harvester Ant Harvests Yucca Seeds

Despite not being recognized by the Parks and associated Friends of the Southwest Nature Preserve in Arlington, Texas (And I have brought this to their attention), the Comanche harvester ant (Pogonomyrmex comanche) is an important part of the ecology of the Glen Rose Yucca Prairie.

This is a small prairie with about 60 Comanche harvester ant colonies.

This is a small prairie with about 60 Comanche harvester ant colonies

There are about 60 colonies in this 4.43 ha meadow.Comanche is generalist seed predator and when the Yucca are releasing their seeds, the ants are harvesting them. I have seen some colonies with all foragers bringing Yucca seeds. So, the ants have the potential to impact the Yucca population.

This Comanche harvester ant is harvesting a Yucca seed in the Southwest Nature Preserve.

This Comanche harvester ant is harvesting a Yucca seed in the Southwest Nature Preserve.

Comanche in SWNP

 

Here is a Comanche nest in the Yucca Meadow: typically a cone shape with a central entrance — the soil is sandy.

Comanche harvester ant nest in the Yucca Meadow

There are many grass and forb plants which have seeds Comanche will forage. Here a forager is bringing back a snake cotton seed. Because of the many hairs on this seed, Comanche appears to use it like Velcro and sometimes collects other seeds with these hairs, thus bringing back more than one seed.

Comanche harvester ant collected  a snake cotton seed

Note the spread of her jaws or mandibles and how she has curled her body around toward the seed.

There are several Comanche nests in the trails at the Southwest Preserve as well. Some of these are quite a distance from the Yucca Meadow.

Comanche harvester ants congregating at their nest

Comanche harvester ants congregating at their nest

The above nest is near the meadow.

Comanche harvester ant nest in a trail

The above nest is in a trail far away from the Yucca meadow. None of the trail nests have as distinctive a crater form.

Finally, there is at least one Barbatus harvester ant colony in a trail at the Southwest Nature Preserve, not far from the Yucca Meadow. This colony has moved it locations a few times over the past 5 years.

Barbatus harvester ant colony

The Comanche harvester ant in the Southwest Nature Preserve

There is a population of 60 colonies of the Comanche harvester ant (Pogonomyrmex comanche) in a small prairie in the Southwest Nature Preserve in Arlington, Texas. I have been studying this population for several years – mapping the colony nest locations, observing their foraging, and testing nestmate discrimination.

Last week I discovered 4 Comanche colonies not in this prairie but in some of the trails in the preserve. There are also two colonies in the trail that goes by the prairie, separated by a line of trees and grass. Of these new colonies, I believe 3 are 3-4 years old and the other is 1-2 years old. It looked as though something or someone had tried to dig into the second and forth of these nests. I examined the areas around all these colonies but the only colonies were actually in the trails.

Locations of Comanche harvester ant colonies in the Southwest Nature Preserve. Note the colonies in green were located this year and are isolated from the main population in red.

Locations of Comanche harvester ant colonies in the Southwest Nature Preserve. Note the colonies in green were located this year and are isolated from the main population in red.

The colonies are probably located in the trails where the soil was more exposed — so easier for a queen to discern that the soil is sandy, easier to dig in, and lacking in much leaf litter and humus. These ants also use the established trail to start out their foraging journeys — this species does not make much use of pheromone trails but relies on vision for orientation.

Their presence in the trails is a bit intriguing. These colonies are separated by 150 – 440 meters and by dense forest from the population I have been studying. I wonder how these queens made it to these locations, how these queens choose their nest sites and how/if these colonies are (or will be — they might not be mature colonies and so not produce alates yet) involved in a mating lek with the colonies in the prairie. The mating of Comanche has not been studied and I have only some observations which suggest that it is different in timing and occurrence from Johnson’s (2000 and 20001) speculation on this species.

There was a lot of foraging going on at the Preserve on Sunday, May 11, 2014. Here are two digital recordings and photos of the Comanche colonies.

Photos of the 4 Comanche nests found in trails. All of these nests were about 30 – 50 cm in a rough diameter (that is, they were not completely round).

First Colony:

Comanche harvester ant (Pogonomyrmex comanche) colony in a trail at the Southwest Nature Preserve, Arlington, Texas

Comanche harvester ant (Pogonomyrmex comanche) colony in a trail at the Southwest Nature Preserve, Arlington, Texas

Second Colony:

Comanche harvester ant (Pogonomyrmex comanche) colony in a trail at the Southwest Nature Preserve, Arlington, Texas

Comanche harvester ant (Pogonomyrmex comanche) colony in a trail at the Southwest Nature Preserve, Arlington, Texas

Close-ups of the two entrances for the second colony (Full photo above):

Close-up of one nest entrance for Comanche colony 2        Close-up of the other entrance of Comanche colony 2

Third Colony:

Comanche harvester ant (Pogonomyrmex comanche) colony in a trail at the Southwest Nature Preserve, Arlington, Texas

Comanche harvester ant (Pogonomyrmex comanche) colony in a trail at the Southwest Nature Preserve, Arlington, Texas

Forth Colony:

Comanche harvester ant (Pogonomyrmex comanche) colony in a trail at the Southwest Nature Preserve, Arlington, Texas

Comanche harvester ant (Pogonomyrmex comanche) colony in a trail at the Southwest Nature Preserve, Arlington, Texas

Here is a digital recording of some Comanche foragers (third colony) getting a scavenged bee into their nest, The little black ant that comes in at times is an acrobatic ant (Crematogaster). This recording is about 10 minutes.

Finally, here is a digital recording of pollinators and pollen eaters in a prickly pear blossom (about 1 minute):

This is a sandy soiled prairie in the Southwest Nature Preserve in Arlington, TX. The Comanche harvester ant, Pogonomyrmex comanche, has about 50 active colonies in this area.

Preliminary Identifications for the SWNP – prairie ants

Here is a list of the ant species, tentatively identified for the Southwest Nature Preserve, Arlington, Texas — from the prairie site where the Comanche harvester ant is nesting.

Crematogaster lineolata

Dorymyrmex flavus and D. sp.

Forelius mccooki

Nylanderia arenivaga and N. vividula

Pheidole sp. (only minors)

Pogonomyrmex comanche

Solenopsis xyloni and Solenopsis sp. (Diplorthoptrum group, thief ants)

Trachymyrmex turrifex

 

Comanche de-alate Queens as foragers

I am collecting more ant samples using pitfall traps to increase the sample size and  the number of different habitats for my ant assemblage study (per the suggestion of one of my committee members). I added two areas from the Southwest Nature Preserve in Arlington, Texas. One site is a mixed soil prairie site where there is a population of the Comanche harvester ant of about 50 colonies. The other is the forested site immediately beside this prairie. I will also be adding two sites from the Tandy Hills in Fort Worth and several more from the Fort Worth Nature Center. Here is the beginning data from the Southwest Nature Preserve:

I set out the traps on September 5 and collected the sample on the 8th. Looks like I have a new Temnothorax species which I haven’t been able to identify yet. I also have a de-alate Comanche queen from the forest. She cannot have been starting a new colony since these ants mate in May and June. This collection confirms my earlier observation of de-alate Comanche queens remaining in their natal nests as foragers in another population.

So far in the prairie: Pogonomyrmex comanche Dorymyrmex (probably two species), Forelius, Pheidole, Nylanderia (two species, maybe three), Trachymyrmex, Temnothorax texanus, Solenopsis (fire ant), Solenopsis (thief ant), and Crematogaster.

In the woods: Aphaenogaster, Pheidole, Crematogaster, de-alate Pogonomyrmex comanche queen, and Temnothorax.

Still working on species identifications. Of course, now I get to redo all my ordination analyses.