Switching Between Intensive and Extensive Searching in Predators of Heterogeneously Distributed Prey

Author

Zy Biesinger, Utah State University

Date of Award:

5-1-2001

Document Type:

Thesis

Degree Name:

Master of Science (MS)

Department:

Biology

Committee Chair(s)

James W. Haefner

Committee

James W. Haefner

Committee

Edward W. Evans

Committee

James A. Powell

Abstract

Many predators of patchily distributed prey are thought to increase their searching efficiency by alternating between extensive and intensive searching behavior. To test the effects of predator satiation and prey density on a ladybird's choice of searching mode, I performed experiments in which larvae of different hunger levels experienced different prey encounter rates. Using traditional measures, I found a beetle's satiation level to have no effect. The prey encounter rate had an effect on two of three traditional measures. Less traditional methods, fractal dimension analysis and Fourier slope analysis, supported the conclusions obtained using traditional measures. Analysis of movement patterns immediately before and after an encounter was conducted to determine the effect of an individual encounter on ladybird behavior. To study the importance of choosing an appropriate sampling interval, the analysis was repeated using eight intervals. Conclusions about the effect of an encounter on immediate behavior varied with the interval.

Recommended Citation

Biesinger, Zy, "Switching Between Intensive and Extensive Searching in Predators of Heterogeneously Distributed Prey" (2001). Biology. 679.
https://digitalcommons.usu.edu/etd_biology/679