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Optimal web investment in sub-optimal foraging conditions
Aaron M T Harmer1, Hanna Kokko, Marie E Herberstein
1Department of Biological Sciences, Macquarie University, Sydney, NSW, 2109, Australia. aharmer@gmail.com
Die Naturwissenschaften
|November 19, 2011
Summary
Orb web spiders adapt their web shape in confined spaces like tree trunks. Models show elongated webs in limited areas increase prey capture efficiency compared to circular webs.
Area of Science:
- * Arachnology
- * Behavioral Ecology
- * Mathematical Modeling
Background:
- * Orb web spiders are central-place foragers, with prey value decreasing with distance from the web hub.
- * Some species build vertically elongated ladder webs on tree trunks, differing from typical circular webs.
- * Ladder web spiders may face reduced prey gain per unit web investment due to web geometry.
Purpose of the Study:
- * To model the influence of space-limited microhabitats on arboricolous ladder web size, shape, and net prey gain.
- * To investigate how spiders optimize web investment in sub-optimal conditions.
Main Methods:
- * Development of a mathematical model to simulate web construction and prey capture in constrained environments.
- * Analysis of how limited horizontal space affects optimal web shape and area.
Main Results:
- * Limited horizontal space leads to more elongated optimal web shapes and decreased optimal web area.
- * This geometric shift reduces net prey gain compared to unconstrained webs.
- * However, in limited spaces, ladder webs yield higher net prey gain than circular webs.
Conclusions:
- * Spiders optimize web investment strategies in constrained foraging arenas.
- * The findings offer insights into foraging trade-offs for central-place foragers in limited environments.
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