Approaches to modelling raccoon rabies

A modelling approach was used to increase understanding of the raccoon-rabies disease-host system. This was achieved through the development and application of the Ontario Rabies Model (ORM). The ORM is a spatially explicit individual-based model (IBM) that simulates raccoon demographics, rabies disease transmission and various rabies control strategies. An important first step before using this new tool for genetic analyses was to validate model processes by assessing parameter input values and their impact on simulated outcomes, and model structure and system processes. This resulted in the creation of a Raccoon Ecology Database (REDB), development of a novel approach to density estimation from capture-mark-recapture data and the incorporation of information theoretic methods into model sensitivity analysis (SA). The REDB confirmed ORM default parameter values fell within known variation, provided sources for citing their values and data for meta-analysis. The REDB also enables parameterisation of the ORM in geographic regions beyond southern Ontario and can be used as an example data model for creating other ecological databases. The method for estimating density from capture-mark-recapture data is applicable to systematic or nonsystematic trapping arrays. Raccoon densities in the St. Lawrence region (44°N 75°W) were found to range from 5 to 6 raccoons/km2 for forest and agricultural habitat, respectively. The SA further ensured that the ORM functions as intended and that the major factors implicated to affect disease-host systems (e.g. density, transmission rate) are also critical factors in the simulated raccoon-rabies system.; Once validated, the ORM was extended to simulate and track maternal and bi-parentally inherited neutral genetic markers. Additional model validation became possible by comparing simulated and empirically derived genetic population structures. The revised model was used to quantify the effect of the Niagara River as a 50% barrier on raccoon movement in the Niagara Region (43°N 79°W) to infer the effect of this landscape barrier on the spread of raccoon-rabies. This work provided further validation of the ORM simulation tool by comparing simulated and empirically derived genetic population structures. Model development and application has increased understanding of the raccoon-rabies system and demonstrated the value of a modelling approach for ecological explorations.; Keywords. individual based model (IBM), raccoon ( Procyon lotor), raccoon rabies, infectious-disease modelling, ecological database, density estimation, sensitivity analysis, neutral genetic markers, landscape genetics, landscape barriers.