Waterbird species are highly mobile and often aggregate in large groups, leading to difficulties assessing their distributions and spatial patterns. Species patterns also vary throughout the year due to migration and habitat preference for both breeding and wintering locations. Yet, waterbirds are a key study group because they are abundant, easily measured, and reactive, making them ideal indicators of environmental change. Identifying persistent areas of high use (i.e., hotspots) for waterbird species is both ecologically and economically beneficial.For Chapter 1, I selected four commonly used hotspot analysis models to evaluate the consistency of approaches for eight species and species groups in the Great Lakes region. Although there was some consistency across models, correlation analyses and mapped results demonstrated that hotspot analysis approaches can produce conflicting results. For Chapter 2, I developed an integrated hotspot modeling approach, in which I combined multiple models to produce a single hotspot value per location. I then used this model to estimate hotspot locations for the eight species groups in surveyed locations across three Great Lakes.The effectiveness of hotspot analyses is dependent upon the quantity and quality of available data, the spatial scale at which data are collected, and the scale at which results are needed (e.g., for management). My work provides researchers and resource managers with a quantitative evaluation of common hotspot analyses techniques. My results also elucidate possible waterbird hotspots in the Great Lakes, providing baseline estimates which can be used to prioritize sampling locations for future waterbird surveys.
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