Developing and Testing TernCOLONY 1.0: An Individual-based Model of Least Tern Reproduction

Abstract : The TernCOLONY simulation model is an individual-based model of Least Tern reproduction that was developed to better understand how reservoir operations (and other management activities) affect Least Tern breeding populations on large rivers. This report documents the process of model development, including defining the model's purpose, its structure, its various submodels, and major inputs. This document supplements the TernCOLONY model description (Lott et al. 2012a), which provides the complete formulation of the model with enough detail to make the model reproducible. This document summarizes the pattern-oriented approach taken in developing the model?s major behavioral traits and submodels (adult tern colony and nest site selection, site abandonment, re-nesting, and various mortality submodels). The report also documents the extensive process of independent verification of the model?s code that was undertaken prior to a whole model sensitivity analysis and parameter calibration (also reported here). The tests reported in this document provide the basis for the final submodels, behavioral traits, and parameter values that are reported in the model description and represented in the model? s code (Lott et al. 2012a). The web version of the model, available at http://www.leasttern.org, is introduced. The web version provides the graphical interface through which most users will explore TernCOLONY. Finally, future directions in the implementation of TernCOLONY on different river reaches are summarized to address a variety of different management applications and discuss the potential for adapting the model to other contexts (e.g., other habitats or species).