Eggshell thinning and decreased concentrations of vitamin E are associated with contaminants in eggs of ivory gulls

►The near-threatened ivory gull is exposed to high levels of contaminants. ►High levels of contaminants were associated with decrease in eggshell thickness. ►The eggshell thinning is close to critical level associated with population decline. ►High levels of contaminants were associated with decrease in α-tocopherol.