Competition and Environmental Variation in the Prey Choice of Los Angeles Car Thieves.

• In Event: Using Optimal Foraging Theory to Understand Offender Target Selection and Exploitation

Abstract

Optimal foraging theory makes several predictions about prey choice. When prey are abundant, foragers should restrict their diet to include only highly-ranked prey types, ignoring lower-ranked prey types when encountered. If preferred prey become rare, foragers should be more flexible and include lower-ranked prey types in the diet when encountered. The availability of prey is directly impacted by predation, but might also be driven by exogenous changes in the environment and the evolution of prey defenses. In addition, competition among predators is expected to play an important role. High predator density should encourage the expansion of diet to include lower-ranked prey types, with the competition effect increasing the more similar predators are in their preferences. Here we apply prey choice models to the problem of car theft, with thieves playing the role of predators and cars of different make-model-years playing the role of prey types. Using recent data from Los Angeles, we examine the effects of spatial and temporal variation in the availability of car types and spatial differences in the inferred density of car thieves on the cars stolen. We investigate the impact the proliferation of keyless ignition systems—an evolved “anti-predator” defense—had on the diet breadth of car thieves and whether higher densities of car thieves drive greater offending variety. To the extent possible, we examine both offender-level behavior and aggregate crime patterns as evidence.

Authors

• P. Jeffrey Brantingham, University of California Los Angeles

• Craig D. Uchida, Justice & Security Strategies, Inc.