Author: S. Andrew InkpenPublisher:
ISBN:
Category : Black and yellow garden spider
Languages : en
Pages : 116
Book Description
Sex-specific Foraging Strategies and Growth in Juveniles of the Highly Dimorphic Orb-web Spider Argiope Aurantia
Author: S. Andrew InkpenPublisher:
ISBN:
Category : Black and yellow garden spider
Languages : en
Pages : 116
Book Description
Sexual Dimorphism and Sexual Selection in the Highly Dimorphic Orb-weaving Spider Argiope Aurantia (Lucas)
Author: Matthias W. FoellmerPublisher:
ISBN:
Category : Black and yellow garden spider
Languages : en
Pages : 0
Book Description
Extreme sexual size dimorphism (SSD) is relatively rare in animal species. Males are much smaller than females for example in anglerfish, some barnacles, and various spiders, Spiders (Araneae) are unique because this is the only free-living terrestrial taxon where extreme SSD is common. The factors involved in the evolution and maintenance of extreme SSD are still poorly understood. Spiders also exhibit a "shape" dimorphism, males having relatively longer legs than females. In this thesis, I estimate selection on adult males of the highly dimorphic orb-weaving spider Argiope aurantia to evaluate hypotheses about the adaptive significance of male size and shape in spiders. I use a multivariate approach to distinguish selection targeting different body components. My results suggest that selection tends to favour longer legs during mate search, and that this may result in net selection for overall larger males. During mating, the pattern of selection on males depends on the type of female with which they mate. Most males mate opportunistically with a moulting female when she is defenceless and are under strong selection for large body size due to interference competition over access to females. If males mate with mature, post-moult females, they face an 80% chance of a cannibalistic attack by the female, but this does not result in selection on male body size. However, the longer males stay in copula, the more likely they are to be cannibalised. Relatively longer legs in males were not favoured during either form of mating and thus probably constitute an adaptation during mate search. Current hypotheses about the adaptive significance of small male size in spiders either predict a small male advantage during mate search or during mating with cannibalistic females, or assume that sexual selection for large size due to interference competition is absent or weak. Neither of these assumptions and predictions were upheld in my study.
Growth and Development in the Orb-weaver Spider, Argiope Aurantia
Author: Joshua L. ShekPublisher:
ISBN:
Category : Black and yellow garden spider
Languages : en
Pages : 41
Book Description
Foraging Specializations in Orb-weaving Spider
Author: Cader Wesley OlivePublisher:
ISBN:
Category : Spiders
Languages : en
Pages : 192
Book Description
Population Dynamics of the Orb Weaving Spiders Argiope Trifasciata and Argiope Aurantia (Araneae, Araneidae)
Author: Wayne Woltz TolbertStochastic Modeling of Orb-web Capture Mechanics Supports the Importance of Rare Large Prey for Spider Foraging Success and Suggests how Webs Sample Available Biomass
Author: Samuel C. EvansPublisher:
ISBN:
Category : Biology
Languages : en
Pages : 55
Book Description
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.
Mating Strategies and Inbreeding in the Orb-weaving Spider Genus Argiope (Araneae: Araneidae)
Author: SEXUALLY DIMORPHIC FORAGING STRATEGIES OF A SALTICID SPIDER (PHIDIPPUS AUDAX)
Author: Robert Parker GivensPublisher:
ISBN:
Category : Animals
Languages : en
Pages : 142
Book Description
Author: Jennifer L. Maupin
Author: Frank Enders