Lancaster EPrints

Effects of predator confusion on functional responses.

Jeschke, Jonathan M. and Tollrian, Ralph (2005) Effects of predator confusion on functional responses. Oikos, 111 (3). pp. 547-555. ISSN 0030-1299

Full text not available from this repository.

Abstract

When confronted with a swarm of their prey, many predators become confused and are less successful in their attacks. To shed light on the ecological, ethological and evolutionary consequences of predator confusion, we here investigate its effects on predator functional responses. We develop the first functional response model that considers confusion and compare it (1) qualitatively as well as (2) quantitatively to empirical data from two predator–prey systems, Aeshna cyanea (Odonata)–Daphnia magna (Crustacea) and Chaoborus obscuripes (Diptera)–Daphnia obtusa. (1) The qualitative comparisons show that, contrary to common belief, confusion does not necessarily lead to a dome-shaped functional response. The response can alternatively remain qualitatively unchanged and be affected only quantitatively. A non-dome-shaped response is thus no indication for the absence of predator confusion. The same is true for other swarming effects reducing foraging success, such as early warning of approaching predators. Our results hence question studies that have equated the absence of a dome-shaped response with the absence of a swarming effect. Our results also resolve the apparent paradox that swarming effects are quite common while dome-shaped functional responses are rather uncommon. (2) There is a good quantitative match between a parameterized version of our model and the empirically measured functional response in the Chaoborus-Daphnia system, suggesting that all crucial factors in this system are captured by the model.

Item Type: Article
Journal or Publication Title: Oikos
Subjects: Q Science > QH Natural history > QH301 Biology
Departments: Faculty of Science and Technology > Lancaster Environment Centre
ID Code: 10646
Deposited By: Mr Richard Ingham
Deposited On: 21 Jul 2008 15:06
Refereed?: Yes
Published?: Published
Last Modified: 17 Sep 2013 10:56
Identification Number:
URI: http://eprints.lancs.ac.uk/id/eprint/10646

Actions (login required)

View Item