Collective Decision-making and Foraging in a Community of Desert Ants

Persistent Link:
http://hdl.handle.net/10150/193758
Title:
Collective Decision-making and Foraging in a Community of Desert Ants
Author:
Lanan, Michele Caroline
Issue Date:
2010
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
Ant colonies are often considered to be a superorganism, exhibiting complex collective behaviors, reproducing at the colony level, and dividing functional roles among groups of workers. For this reason, it is often appropriate to study ant behavior at the colony, rather than the individual, level. In this study, I investigated decision-making and foraging behavior in colonies of several species belonging to the ant community of Sonoran Desert scrub habitat. First, I used laboratory experiments to examine how the spatial structure of Crematogaster torosa colonies changes in response to the availability of temporally stable food sources. I found that in this polydomous species the formation of nests is associated with foraging, but that colonies will build broodless structures called “oustations” regardless of food presence. Next, I examined colony spatial structure of a related polydomous species, Crematogaster opuntiae, in the field. I found that colonies used large foraging territories up to three hectares in size, containing up to twenty nest entrances interconnected by a network of trails. Nest location appeared to be related to foraging, with nests located close to extrafloral nectar-secreting cacti (Ferocactus wislizeni) and a negative relationship between cactus density and territory size. Within colonies, forager behavior on neighboring cacti was not independent at short distances, suggesting that separate plants in this system cannot be treated as independent replicates. In the third chapter, I used an individual-based simulation model to investigate the effects of individual worker behavior on the ability of pheromone-recruiting ant colonies to maintain trails to multiple food sources simultaneously. Interestingly, small changes in the behavior rules used by individuals led to large-scale changes in emergent behaviors at the colony level. Lastly, I used field experiments to relate the ability of colonies of three ant species to maintain multiple trails to their ranking in the community competitive dominance hierarchy. I found that the most dominant species tended to forage asymmetrically, whereas the least dominant species exhibited more symmetrical patterns of foraging. The ability of ant colonies to collectively maintain multiple trails may therefore be an adaptive trait linked to the foraging ecology of species.
Type:
text; Electronic Dissertation
Keywords:
Ants; Collective Behavior; Competition; Foraging; Polydomy; Symmetry Breaking
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Insect Science; Graduate College
Degree Grantor:
University of Arizona
Advisor:
Bronstein, Judith L.
Committee Chair:
Bronstein, Judith L.

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titleCollective Decision-making and Foraging in a Community of Desert Antsen_US
dc.creatorLanan, Michele Carolineen_US
dc.contributor.authorLanan, Michele Carolineen_US
dc.date.issued2010en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractAnt colonies are often considered to be a superorganism, exhibiting complex collective behaviors, reproducing at the colony level, and dividing functional roles among groups of workers. For this reason, it is often appropriate to study ant behavior at the colony, rather than the individual, level. In this study, I investigated decision-making and foraging behavior in colonies of several species belonging to the ant community of Sonoran Desert scrub habitat. First, I used laboratory experiments to examine how the spatial structure of Crematogaster torosa colonies changes in response to the availability of temporally stable food sources. I found that in this polydomous species the formation of nests is associated with foraging, but that colonies will build broodless structures called “oustations” regardless of food presence. Next, I examined colony spatial structure of a related polydomous species, Crematogaster opuntiae, in the field. I found that colonies used large foraging territories up to three hectares in size, containing up to twenty nest entrances interconnected by a network of trails. Nest location appeared to be related to foraging, with nests located close to extrafloral nectar-secreting cacti (Ferocactus wislizeni) and a negative relationship between cactus density and territory size. Within colonies, forager behavior on neighboring cacti was not independent at short distances, suggesting that separate plants in this system cannot be treated as independent replicates. In the third chapter, I used an individual-based simulation model to investigate the effects of individual worker behavior on the ability of pheromone-recruiting ant colonies to maintain trails to multiple food sources simultaneously. Interestingly, small changes in the behavior rules used by individuals led to large-scale changes in emergent behaviors at the colony level. Lastly, I used field experiments to relate the ability of colonies of three ant species to maintain multiple trails to their ranking in the community competitive dominance hierarchy. I found that the most dominant species tended to forage asymmetrically, whereas the least dominant species exhibited more symmetrical patterns of foraging. The ability of ant colonies to collectively maintain multiple trails may therefore be an adaptive trait linked to the foraging ecology of species.en_US
dc.typetexten_US
dc.typeElectronic Dissertationen_US
dc.subjectAntsen_US
dc.subjectCollective Behavioren_US
dc.subjectCompetitionen_US
dc.subjectForagingen_US
dc.subjectPolydomyen_US
dc.subjectSymmetry Breakingen_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineInsect Scienceen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorBronstein, Judith L.en_US
dc.contributor.chairBronstein, Judith L.en_US
dc.contributor.committeememberDornhaus, Annaen_US
dc.contributor.committeememberPapaj, Danielen_US
dc.contributor.committeememberHunter, Marthaen_US
dc.identifier.proquest11270en_US
dc.identifier.oclc752261112en_US
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