Skip to Main Content
 

Global Search Box

 
 
 
 

Files

File List


EvansS.the (final comments).pdf (2.16 MB)

ETD Abstract Container

Abstract Header

Stochastic Modeling of Orb-Web Capture Mechanics Supports the Importance of Rare Large Prey for Spider Foraging Success and Suggests How Webs Sample Available Biomass

Evans, Samuel C
http://rave.ohiolink.edu/etdc/view?acc_num=akron1384443854

Abstract Details

2013, Master of Science, University of Akron, Biology.
Strong selective pressures can be exerted by events that occur extremely rarely and unpredictably during an organism's lifetime. The importance of such rare events may elude detection if the fitness consequences are not immediately observable, such as in the form of missed foraging opportunities. For orb-weaving spiders, fitness may depend almost exclusively on securing one or a few large, rarely-encountered, difficult-to-capture prey. Here, we present a stochastic individual-based model simulating foraging, growth, and survival of various-sized spiders in environments varying in distribution of biomass among prey sizes. We use this model to assess the degree to which foraging success is determined by the outcome of a small subset of foraging opportunities, and ascertain the architectural and biomechanical properties most crucial to deciding the outcomes of these rare events. Although our deterministic model suggests spiders should, on average, gain the most biomass from small prey sizes, spiders in stochastic simulations grew the most by capturing a single large and difficult-to-capture prey comprising the majority of their diets. The mechanics involved in stopping and retaining flying prey were more important in determining foraging success compared to those involved in encountering and contacting prey. Spiders lost the raw majority of biomass they encountered by failing to stop prey. However, prey retention exhibited the highest rate of biomass loss—spiders lost over 90% of successfully stopped biomass by failing to retain prey, but failed to stop only 40-80% of prey biomass their webs successfully contacted. Our results support the rare large prey hypothesis of Venner and Casas (2005), and reinforce the hypothesis that orb webs are pervasively selected for their potential to arrest large amounts of energy. However, certain factors such as prey availability and the biomechanics of prey retention in webs warrant further investigation, as these may be crucial to the plausibility of alternative foraging strategies.
Todd Blackledge, Dr. (Advisor)
Randall Mitchell, Dr. (Committee Member)
Stephen Weeks, Dr. (Committee Member)
63 p.
Biology; Biomechanics
foraging; spider; orb web; insect; prey; biomechanics; stochastic; deterministic; model

Recommended Citations

Citations

  • Evans, S. C. (2013). Stochastic Modeling of Orb-Web Capture Mechanics Supports the Importance of Rare Large Prey for Spider Foraging Success and Suggests How Webs Sample Available Biomass [Master's thesis, University of Akron]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=akron1384443854

    APA Style (7th edition)

  • Evans, Samuel. Stochastic Modeling of Orb-Web Capture Mechanics Supports the Importance of Rare Large Prey for Spider Foraging Success and Suggests How Webs Sample Available Biomass. 2013. University of Akron, Master's thesis. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=akron1384443854.

    MLA Style (8th edition)

  • Evans, Samuel. "Stochastic Modeling of Orb-Web Capture Mechanics Supports the Importance of Rare Large Prey for Spider Foraging Success and Suggests How Webs Sample Available Biomass." Master's thesis, University of Akron, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=akron1384443854

    Chicago Manual of Style (17th edition)

akron1384443854
743
© 2013, some rights reserved.Creative Commons License Stochastic Modeling of Orb-Web Capture Mechanics Supports the Importance of Rare Large Prey for Spider Foraging Success and Suggests How Webs Sample Available Biomass by Samuel C Evans is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License. Based on a work at etd.ohiolink.edu.
This open access ETD is published by University of Akron and OhioLINK.