Summary & Purpose

There is widespread evidence that human disturbance affects wildlife behavior, but long-term population effects can be difficult to quantify. Individual-based models (IBMs) offer a way to assess population-level, aggregate effects of disturbance on wildlife. We created Tolerance in Raptors and the Associated Impacts of Leisure Sports (TRAILS), an IBM that simulates interactions between recreationists and nesting raptors, to assess the effect of human disturbance on raptor populations and test if changes in tolerance to disturbance could mitigate negative consequences. We used behavioral and demographic data from golden eagles Aquila chrysaetos, and recreation activity data to parameterize TRAILS and simulate the effects of pedestrian and off-highway vehicle (OHV) recreation on the likelihood of territory occupancy, egg-laying and nest survival of eagles over 100 years. We modeled eagle populations in the absence of recreation, with stationary 2014 levels of recreation, and with annual increases in recreation. Furthermore, we simulated eagles that developed tolerance to disturbance randomly, through natural selection, habitat imprinting, or habituation. In the presence of recreation, simulated eagle populations had significantly lower and more variable growth rates, population sizes and territory occupancy. Annual increases in recreation of 1–2% greatly exacerbated population declines. Though both habituation and natural selection lead to more tolerant eagle populations, neither buffered eagle populations from detrimental effects of recreation. These results suggest that long-lived species that experience encroachment from human activities may not adapt to human disturbance at a rate that compensates for changes in disturbance. This project illustrates the usefulness of IBMs for evaluating non-lethal threats, forecasting population changes and testing theoretical feedbacks in system processes.

Author Identifier

Robert J Spaul 0000-0003-1524-908X Julie A Heath 0000-0002-9606-1689


Funding Citation

This research was supported by the NSF Idaho EPSCoR Program and by the National Science Foundation under award number IIA-1301792, the Raptor Research Center and Department of Biological Sciences at Boise State University, the Bureau of Land Management and the USFWS Western Golden Eagle Team. Computing resources for this material is based in part upon work supported by the National Science Foundation under Grant No. 1229709.

Single Dataset or Series?

Single Dataset

Data Format


Data Attributes

The data spreadsheet is accompanied by a list of column headings and their meanings.

Privacy and Confidentiality Statement

Boise State University is explicitly compliant with federal and state laws surrounding data privacy including the protection of personal financial information through the Gramm-Leach-Bliley Act, personal medical information through HIPAA, HITECH and other regulations. All human subject data (e.g., surveys) has been collected and managed only by personnel with adequate human subject protection certification.

Use Restrictions

General Restrictions: Users are free to share, copy, distribute and use the dataset; to create or produce works from the dataset; to adapt, modify, transform and build upon the dataset as long as the user attributes any public use of the dataset, or works produced from the dataset, referencing the author(s) and DOI link. For any use or redistribution of the dataset, or works produced from it, the user must make clear to others the license of the dataset and keep intact any notices on the original dataset.

NSF EPSCoR MILES Restrictions: Data will be provided to all who agree to appropriately acknowledge the National Science Foundation (NSF), Idaho EPSCoR and the individual investigators responsible for the data set. By downloading these data and using them to produce further analysis and/or products, users agree to appropriately acknowledge the National Science Foundation (NSF), Idaho EPSCoR and the individual investigators responsible for the data set. Use constraints: Acceptable uses of data provided by Idaho EPSCoR include any academic, research, educational, governmental, recreational, or other not-for-profit activities. Any use of data provided by the Idaho EPSCoR must acknowledge Idaho EPSCoR and the funding source(s) that contributed to the collection of the data. Users are expected to inform the Idaho EPSCoR Office and the PI(s) responsible for the data of any work or publications based on data provided.


Article Location