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- All Subjects: Ants
- Creators: Pavlic, Theodore
Description
Temnothorax ants are a model species for studying collective decision-making. When presented with multiple nest sites, they are able to collectively select the best one and move the colony there. When a scout encounters a nest site, she will spend some time exploring it. In theory she should explore the site for long enough to determine both its quality and an estimate of the number of ants there. This ensures that she selects a good nest site and that there are enough scouts who know about the new nest site to aid her in relocating the colony. It also helps to ensure that the colony reaches a consensus rather than dividing between nest sites. When a nest site reaches a certain threshold of ants, a quorum has been reached and the colony is committed to that nest site. If a scout visits a good nest site where a quorum has not been reached, she will lead a tandem run to bring another scout there so that they can learn the way and later aid in recruitment. At a site where a quorum has been reached, scouts will instead perform transports to carry ants and brood there from the old nest. One piece that is missing in all of this is the mechanism. How is a quorum sensed? One hypothesis is that the encounter rate (average number of encounters with nest mates per second) that an ant experiences at a nest site allows her to estimate the population at that site and determine whether a quorum has been reached. In this study, encounter rate and entrance time were both shown to play a role in whether an ant decided to lead a tandem run or perform a transport. Encounter rate was shown to have a significant impact on how much time an ant spent at a nest site before making her decision, and encounter rates significantly increased as migrations progressed. It was also shown to individual ants did not differ from each other in their encounter rates, visit lengths, or entrance times preceding their first transports or tandem runs, studied across four different migrations. Ants were found to spend longer on certain types of encounters, but excluding certain types of encounters from the encounter rate was not found to change the correlations that were observed. It was also found that as the colony performed more migrations, it became significantly faster at moving to the new nest.
ContributorsJohnson, Christal Marie (Author) / Pratt, Stephen (Thesis director) / Pavlic, Theodore (Committee member) / Shaffer, Zachary (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor)
Created2013-05
Description
Across the animal kingdom, communication serves a vital purpose. The transfer of information between and among species is often paramount to many behaviors including mating, collaboration, and defense. While research has provided tremendous insight into animal communication and interaction, there is still much that we have yet to understand. Due to their reliance on interactions that maximize efficiency within their complicated colony structure and array of member roles, eusocial insects serve as an excellent model for animal communication. Among eusocial insects, ants are some of the most heavily researched, with a tremendous amount of literature focused on their cuticular hydrocarbons. Along with serving as a waterproofing agent, cuticular hydrocarbons also play a major role in recognition and communication in these insects. By studying the importance of hydrocarbons in ant social structure, their tremendously specialized olfactory system, and the use of learning assays in its study, parallels between communication in ants and other animals are revealed, demonstrating how ants serve as a relevant model for animal communication as a whole.
ContributorsSpirek, Benton Forest Ensminger (Author) / Liebig, Juergen (Thesis director) / Pratt, Stephen (Committee member) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2020-12
Description
The desert ant, Novomessor albisetosus, is an ideal model system for studying collective transport in ants and self-organized cooperation in natural systems. Small teams collect and stabilize around objects encountered by these colonies in the field, and the teams carry them in straight paths at a regulated velocity back to nearby nest entrances. The puzzling finding that teams are slower than individuals contrasts other cases of cooperative transport in ants. The statistical distribution of speeds has been found to be consistent with the slowest-ant model, but the key assumption that individual ants consistently vary in speed has not been tested. To test this, information is needed about the natural distribution of individual ant speeds in colonies and whether some ants are intrinsically slow or fast. To investigate the natural, individual-level variation in ants carrying loads, data were collected on single workers carrying fig seeds in arenas separated from other workers. Using three separate, small arenas, the instantaneous speed of each seed-laden worker was recorded when she picked up a fig seed and transported within the arena. Instantaneous speeds were measured by dividing the distance traveled in each frame by how much time had passed.
There were nine ants who transported a fig seed numerous times and there was a clear variation in their average instantaneous speed. Within an ant, slightly varying speeds were found as well, but within-ant speeds were not as varied as speed across ants. These results support the conclusion that there is intrinsic variation in the speed of an individual which supports the slowest-ant model, but this may require further experimentation to test thoroughly. This information aids in the understanding of the natural variation of ants cooperatively carrying larger loads in groups.
There were nine ants who transported a fig seed numerous times and there was a clear variation in their average instantaneous speed. Within an ant, slightly varying speeds were found as well, but within-ant speeds were not as varied as speed across ants. These results support the conclusion that there is intrinsic variation in the speed of an individual which supports the slowest-ant model, but this may require further experimentation to test thoroughly. This information aids in the understanding of the natural variation of ants cooperatively carrying larger loads in groups.
ContributorsCastro, Samantha (Author) / Pavlic, Theodore (Thesis director) / Pratt, Stephen (Committee member) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2020-12