Physiological health of wintering glaucous-winged gulls in coastal British Columbia

We assessed physiological health of glaucous-winged gulls wintering in urban and natural habitats in the Salish Sea, British Columbia. Although ecological context differed among sites, based on stable isotope analysis, physiological health did not vary with location or habitat. Our study provides physiological reference values for future biomonitoring., Methods
Study area
The Salish Sea (49° 20' 10.4\", -123° 50' 21.6\") comprises two areas of sheltered marine waters harbouring large human population centres: the Strait of Georgia in Southern British Columbia and Puget Sound in Washington State, which are connected to the open Pacific Ocean by the exposed Strait of Juan de Fuca. In January and February of 2020 and 2021, we sampled adult GWGUs throughout the Canadian portion of the Salish Sea (Figure 1). We attempted to sample evenly between the following regions: ‘Lower Mainland’, ‘Greater Victoria’, ‘Southern Vancouver Island’, and the ‘Northern Salish Sea.’ Regions were categorized primarily by geographic proximity, but generally had similar beach substrate types and levels of anthropogenic influence throughout a given region (Supplemental Figures 1 and 2).
Within each region, we sampled as evenly as possible among various habitat types including landfills, ‘urban,’ and ‘natural’ areas (Table 1). However, levels of human population den..., # Physiological health of wintering glaucous-winged gulls in coastal British Columbia

Dataset DOI: [10.5061/dryad.z08kprrrp](10.5061/dryad.z08kprrrp)

## Description of the data and file structure

We assessed variation in physiological health, sex ratio, and body mass of glaucous-winged gulls (GWGUs) wintering in the Salish Sea region of BC, in relation to anthropogenic activity (based on capture locations) and diet (via stable isotopes). In particular, we measured a suite of physiological markers commonly used in biomonitoring, which can be interpreted with respect to several aspects of health (Kophamel *et al.,* 2021; Whitehead and Dunphy, 2022). Since interpretation of multiple biomarkers can be strengthened within the broader context of an individual’s health (Mallory *et al.,* 2010; Warne *et al.,* 2015; Whitehead and Dunphy, 2022) these biomarkers were incorporated to generate indices of ‘overall health’ of individuals using principle components analysis. Specifically our object...,