Abstract

Gulls (Larids) have mastered the art of foraging in human-created areas. However, little is known about the health effects of using anthropogenic habitats and the exposure to environmental pollutants that comes with it. This is especially true when it comes to plasma biochemistry, which is frequently used to diagnose physiological disorders and diseases. The plasma biochemistry of urban-breeding ring-billed gulls (Larus delawarensis) from one of the largest North American colonies was the subject of this study, which sought to investigate the effects of anthropogenic habitat use and exposure to ubiquitous halogenated flame retardants (HFRs). Individual gulls’ foraging habitat use was characterized using miniature GPS dataloggers (n = 39) in the Montreal area (QC, Canada) at the regional scale (urban, waste management facilities, agricultural fields, and St. Lawrence River), and plasma was analyzed for a suite of biochemical measures (waste products, lipids, glucose, ions, proteins, and enzymes) and HFRs. Sex, body condition, the amount of time spent fasting while incubating, plasma thyroid hormone levels, the time of day, the capture date, and the ambient temperature were all evaluated as potential confounding biological and environmental variables.

Keywords: Polybrominated diphenyl ethers; Dechlorane plus; Clinical chemistry