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- All Subjects: Foraging
- Creators: Foltz-Sweat, Jennifer
- Creators: Hölldobler, Bert
Description
The coordination of group behavior in the social insects is representative of a broader phenomenon in nature, emergent biological complexity. In such systems, it is believed that large-scale patterns result from the interaction of relatively simple subunits. This dissertation involved the study of one such system: the social foraging of the ant Temnothorax rugatulus. Physically tiny with small population sizes, these cavity-dwelling ants provide a good model system to explore the mechanisms and ultimate origins of collective behavior in insect societies. My studies showed that colonies robustly exploit sugar water. Given a choice between feeders unequal in quality, colonies allocate more foragers to the better feeder. If the feeders change in quality, colonies are able to reallocate their foragers to the new location of the better feeder. These qualities of flexibility and allocation could be explained by the nature of positive feedback (tandem run recruitment) that these ants use. By observing foraging colonies with paint-marked ants, I was able to determine the `rules' that individuals follow: foragers recruit more and give up less when they find a better food source. By altering the nutritional condition of colonies, I found that these rules are flexible - attuned to the colony state. In starved colonies, individual ants are more likely to explore and recruit to food sources than in well-fed colonies. Similar to honeybees, Temmnothorax foragers appear to modulate their exploitation and recruitment behavior in response to environmental and social cues. Finally, I explored the influence of ecology (resource distribution) on the foraging success of colonies. Larger colonies showed increased consistency and a greater rate of harvest than smaller colonies, but this advantage was mediated by the distribution of resources. While patchy or rare food sources exaggerated the relative success of large colonies, regularly (or easily found) distributions leveled the playing field for smaller colonies. Social foraging in ant societies can best be understood when we view the colony as a single organism and the phenotype - group size, communication, and individual behavior - as integrated components of a homeostatic unit.
ContributorsShaffer, Zachary (Author) / Pratt, Stephen C (Thesis advisor) / Hölldobler, Bert (Committee member) / Janssen, Marco (Committee member) / Fewell, Jennifer (Committee member) / Liebig, Juergen (Committee member) / Arizona State University (Publisher)
Created2014
Description
One can argue that bees are the most unique insects in the animal kingdom due to their invaluable services they provide on a global level. Their importance goes beyond their capability of pollination; it is shown in their environmental impact and maintenance of the world's food supply. It is evident that the bee population is experiencing a serious and rapid decline that has resulted in changes to ecosystems in the past couple of decades. In order to resolve these issues, further research must be conducted to understand what humans can do to benefit their species' longevity. It is necessary for knowledge regarding bees, specifically their foraging behavior, to improve so humans can understand their essentiality to not only them, but the world. The focus of this study is to address any differences in foraging behavior between Apis mellifera, the honey bee, and native bee species. Other questions were answered including: do native and non-native bees have floral host preferences? Do native and non-native bees visit a variety of floral hosts? Experimental procedures were conducted to address these questions, which involved netting bees at differing times in four varying garden locations at the Desert Botanical Garden in Phoenix, Arizona. Then, the preparation of bee pollen and plant pollen slides along with bee mounting was performed. After the completion of data analysis, it was discovered that the preliminary data showed different foraging behavior between native and non-native bee species. Further studies are pertinent in obtaining statistically significant data due to an insufficient sample proportion. This is crucial in understanding the true differences in behaviors between both bee species.
ContributorsPerez, Czarinabelle Eunice (Author) / Foltz-Sweat, Jennifer (Thesis director) / Sweat, Ken (Committee member) / School of Social and Behavioral Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2018-12
Description
An insect society needs to share information about important resources in order to collectively exploit them. This task poses a dilemma if the colony must consider multiple resource types, such as food and nest sites. How does it allocate workers appropriately to each resource, and how does it adapt its recruitment communication to the specific needs of each resource type? In this dissertation, I investigate these questions in the ant Temnothorax rugatulus.
In Chapter 1, I summarize relevant past work on food and nest recruitment. Then I describe T. rugatulus and its recruitment behavior, tandem running, and I explain its suitability for these questions. In Chapter 2, I investigate whether food and nest recruiters behave differently. I report two novel behaviors used by recruiters during their interaction with nestmates. Food recruiters perform these behaviors more often than nest recruiters, suggesting that they convey information about target type. In Chapter 3, I investigate whether colonies respond to a tradeoff between foraging and emigration by allocating their workforce adaptively. I describe how colonies responded when I posed a tradeoff by manipulating colony need for food and shelter and presenting both resources simultaneously. Recruitment and visitation to each target partially matched the predictions of the tradeoff hypothesis. In Chapter 4, I address the tuned error hypothesis, which states that the error rate in recruitment is adaptively tuned to the patch area of the target. Food tandem leaders lost followers at a higher rate than nest tandem leaders. This supports the tuned error hypothesis, because food targets generally have larger patch areas than nest targets with small entrances.
This work shows that animal groups face tradeoffs as individual animals do. It also suggests that colonies spatially allocate their workforce according to resource type. Investigating recruitment for multiple resource types gives a better understanding of exploitation of each resource type, how colonies make collective decisions under conflicting goals, as well as how colonies manage the exploitation of multiple types of resources differently. This has implications for managing the health of economically important social insects such as honeybees or invasive fire ants.
In Chapter 1, I summarize relevant past work on food and nest recruitment. Then I describe T. rugatulus and its recruitment behavior, tandem running, and I explain its suitability for these questions. In Chapter 2, I investigate whether food and nest recruiters behave differently. I report two novel behaviors used by recruiters during their interaction with nestmates. Food recruiters perform these behaviors more often than nest recruiters, suggesting that they convey information about target type. In Chapter 3, I investigate whether colonies respond to a tradeoff between foraging and emigration by allocating their workforce adaptively. I describe how colonies responded when I posed a tradeoff by manipulating colony need for food and shelter and presenting both resources simultaneously. Recruitment and visitation to each target partially matched the predictions of the tradeoff hypothesis. In Chapter 4, I address the tuned error hypothesis, which states that the error rate in recruitment is adaptively tuned to the patch area of the target. Food tandem leaders lost followers at a higher rate than nest tandem leaders. This supports the tuned error hypothesis, because food targets generally have larger patch areas than nest targets with small entrances.
This work shows that animal groups face tradeoffs as individual animals do. It also suggests that colonies spatially allocate their workforce according to resource type. Investigating recruitment for multiple resource types gives a better understanding of exploitation of each resource type, how colonies make collective decisions under conflicting goals, as well as how colonies manage the exploitation of multiple types of resources differently. This has implications for managing the health of economically important social insects such as honeybees or invasive fire ants.
ContributorsCho, John Yohan (Author) / Pratt, Stephen C (Thesis advisor) / Hölldobler, Bert (Committee member) / Liebig, Jürgen R (Committee member) / Amazeen, Polemnia G (Committee member) / Rutowski, Ronald L (Committee member) / Arizona State University (Publisher)
Created2019
Description
Honey bees are vital to human society due to their pollination services but are currently under threat due to various factors. In order to avoid drastic declines in bee populations, it is important to fully understand factors that contribute to pollinator health and efficiency. The focus of this experiment were UV markings, commonly referred to as nectar guides. While various studies have found nectar guides to influence pollinator activity, relatively few experiments have been conducted to see how UV patterns and/or UV coverage of nectar guides affects bee foraging, which is what our experiment attempted to explore. Our hypothesis was that UV coverage has a positive impact on bee foraging activity, but that full UV coverage would lower foraging activity, we also hypothesized that UV pattern would also influence foraging activity and that pollinators will prefer circular patterns. In our experiment we created artificial nectar dispensing flowers with differing UV markings and placed them out in a natural environment and recorded pollinator visitation. We then utilized a two-way ANOVA to determine if there was a statistical correlation between UV abundance and/or UV pattern on pollinator activity. Our results revealed no statistical correlation for either UV coverage (p = .389) nor UV pattern (p = .437) to pollinator activity. While no statistical correlation was found, graphical analysis of the mean between different UV groups revealed a noticeable flower preference was seen for flowers with at least some level of UV compared to no UV and a slight increase in activity for circular patterns compared to radial patterns. This suggests that perhaps UV abundance and pattern plays a minor role in pollinator activity but nothing that is statistically significant. We suggest further follow up research to improve and refine our methods and utilize a greater range of patterns and abundance size with a larger sample size to better understand the role UV pattern and UV coverage has on pollinator foraging activity.
ContributorsLazau, Joshua (Author) / Foltz-Sweat, Jennifer (Thesis director) / Sweat, Ken (Committee member) / School of Social and Behavioral Sciences (Contributor) / School of Mathematical and Natural Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05