Integrating human behavior into structured population models

Abstract

Human behavior shapes modern ecosystems but is difficult to parse into parameters for ecological models. We used Bayesian models of human behavior, a stage-structured population model, and a novel mortality integration approach to ask how human decisions affect animal population dynamics and conservation outcomes in the context of recreational fishing. Walleye (Sander vitreus) are a broadcast-spawning freshwater fish with large, slow-maturing females and small, fast-maturing males. We observed that simpler and less restrictive fishing regulations outperformed more complex and stricter regulations at conserving equilibrium adult female abundance and overall population abundance while still facilitating large harvests. This outcome was possible because angler behavior within the least restrictive regulation concentrated harvest on juveniles and adult males. Our findings indicate that, counter to intuitive expectations, moderate regulations can acheive conservation objectives when we account for the interaction of regulatory policy, human behavior, and animal life history. We suggest that integrating models of human behavior with models of animal life history and population dynamics will provide essential insights for conservation in ecosystems increasingly shaped by human decisions.