USM Professor Leads Research Team to Study How Climate Affects Ant Colonies
Tue, 07/05/2022 - 11:37am | By: Van Arnold
The more queens, the better – such is the conclusion reached by University of Southern
Mississippi (USM) scientist Dr. Kaitlin Baudier and her team after conducting intensive
research on specific ant colonies in the desert Southwest.
Dr. Madeleine Ostwald uses an aspirator to collect California harvester ants from a nest entrance.
Baudier and collaborators at Arizona State University spent the better part of a year studying California harvester ants (Pogonomyrmex californicus) from the Pine Valley, Calif., region to test how multi-queen versus single-queen colonies perform in extreme climates. Their work has been accepted for publication in Physiological and Biochemical Zoology.
Baudier, Assistant Professor in USM’s School of Biological, Environmental and Earth Sciences, points out that typically an ant queen founds a colony by herself. Yet sometimes queens work together in groups of two or more to accomplish this complicated task.
“This cooperative strategy allows the colony to grow bigger faster and reduces the likelihood that any one queen will die but comes at the cost of lower numbers of offspring per queen,” said Baudier. “Because of this, cooperative founding has evolved multiple times in ants that live in very climatically harsh (hot or cold) and very seasonal environments like those found at high latitudes, high elevations, or deserts.”
The researchers wanted to know if having multiple queens per colony also directly affects the thermal physiology of the worker ants themselves (the queen's, or queens' non-reproductive babies), which could be another benefit of investing in this strategy in certain environments.
Dr. Kaitlin Baudier with an aspirator used to collect ants.
“To test this, we studied a species of ant native to the mountains of the desert Southwest, where winters are snowy and summers are dry and scorching hot,” said Baudier. “We reared colonies of California harvester ants (Pogonomyrmex californicus) with one, two, or four queens and after 10 months of growth, we measured all of the ants' heat tolerances.
Added Baudier, “Consistent with predictions, we found that colonies with more queens had higher heat tolerance than those with only one. This enables colonies with multiple queens to send out more foragers for longer periods in the day during summer, which adds to colony productivity.”
Other members of the research team included:
- Madeleine M. Ostwald, PhD - PhD student at Arizona State University at the time, now Dr. Ostwald, a postdoc at UC Santa Barbara, who shared first authorship of the research paper
- Brian R. Haney, PhD - Assistant Professor at the College of Mount Saint Vincent who added a rich set of logged temperature data from the field site
- Frank Cossio - Former undergraduate researcher at Arizona State University, now medical student who helped collect a lot of the thermal tolerance data
- Juliana Calixto - PhD student at Arizona State University who collect a lot of the thermal tolerance data
- Jennifer Fewell, PhD - Professor at Arizona State University, principal investigator of the lab in which the research was done.
With regards to the benefits of this research, Baudier explains that understanding patterns in organismal thermal performance is essential to predicting which environments and species are most hard-hit by climate change.
“On a more basic level, this work also broadens our understanding of the benefits of non-kin cooperation,” she said. In other words, when, where and why is it beneficial to work together with a stranger.”
To learn more about the USM School of Biological, Environmental and Earth Sciences, call 601.266.4748 or visit: https://www.usm.edu/biological-environmental-earth-sciences/index.php