Thesis Defense - Enhancing coastal migratory shorebird conservation

Shorebirds are an ecologically and economically important group of organisms that are experiencing global widespread population declines. A leading driver of population declines is the loss of important coastal habitats, especially tidal flats at staging and stopover sites. To increase understanding of the condition of globally distributed coastal shorebird habitats and prevent further loss of these species, a novel habitat quality assessment framework termed the “Shorebird Stopover and Staging Habitat Quality Index” (SSSHQI), was developed. The index’s purpose was to estimate the relative quality of coastal habitats used by migratory shorebirds thereby allowing for more informed conservation planning and efficient allocation of resources for management. Biophysical and distributional habitat quality proxy measures related to foraging and roosting habitats were selected for the SSSHQI, which combined the measures into a single numerical value representative of relative habitat quality. As a proof of concept, the SSSHQI was applied to two case study sites: the Fraser River Estuary, Canada and Port Curtis, Australia. Following this, a pre-feasibility study was employed to explore the SSSHQI’s strengths, limitations, and viability as a tool for shorebird conservation. The SSSHQI’s results suggested that both case study sites were “Good” quality habitats, each with strengths and deficiencies related to foraging and roosting habitat. The pre- feasibility analysis revealed that aspects of the index that measure roosting site quality and shorebird diversity, considerably rely on previously collected data. If these data requirements were met the SSSHQI’s proxies were simple, low-cost, and informative measures to assess and compare the relative quality of different coastal shorebird habitats. However, adjusting scoring schemes to account for site specific differences in tidal flat morphology and refining proxy measures to consider important upper tidal flat areas would improve the SSSHQI’s accuracy and increase its utility to understand the quality of coastal shorebird staging and stopover habitats.