Evaluation of the usefulness of bird feathers as a non-destructive biomonitoring tool for organic pollutants: A comparative and meta-analytical approach

Abstract

Abstract:In this study, we investigated whether bird feathers can be used as a non-destructive biomonitor for organic pollutants. We analysed the outermost tail feathers of 8 terrestrial and aquatic bird species from Belgium (8 species, n=108) for polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and organochlorine pesticides (OCPs). Every compound class could be quantified in one single tail feather of the birds under study (sum PCBs ranging from 5.5 to 510 ng/g feather, sum PBDEs from 0.33 to 53 ng/g feather, sum DDTs from 1.5 to 730 ng/g feather), except for PBDEs in feathers of the common moorhen (Gallinula chloropus). Further, we calculated Pearson correlations between concentrations of organic pollutants in feathers and concentrations in corresponding muscle or liver tissue from the birds. Correlations were found significant in half of the cases of the terrestrial species, but were found not significant for the aquatic species, with the exception of a significant correlation of sum PCBs in the common moorhen. Only for the common buzzard (Buteo buteo) (n=43) all correlations were found significant (0.32<r<0.77). In order to cope for low statistical power, we performed a meta-analysis on all bird species together. This led to significant correlations between levels in feathers and corresponding levels in muscle or liver for all terrestrial birds (p<0.05 in all cases, effect size 0.59 (p,p'-DDE) to 0.71 (∑ PCB) for levels in feather and muscle). When correlations were recalculated excluding the birds that had died due to starvation, correlation coefficients for the terrestrial birds were found even higher (effect size up to 0.83 (∑ PCB)). These results have important implications for non-destructive and retrospective biomonitoring. Although our results suggest that exact concentrations in the body cannot be predicted using feathers, bird feathers can give a good estimate of contamination levels in a population and as such are a potential non-destructive biomonitoring tool for organic pollutants.Outermost tail feathers and muscle tissue were also examined for nitrogen (δ 15 N) and carbon (δ 13 C) stable isotope content in the different bird species. However, δ 15 N/δ 13 C signatures in feather or muscle were not significantly correlated with the corresponding levels of organic pollutants in these tissues. Various confounding factors (such as habitat, condition, age, sex) may have masked a relationship between δ 15 N values and organic pollutant levels in the birds under study.

Evaluation of Noninvasive Approach for Monitoring PCB Pollution of Seabirds Using Preen Gland Oil

“…Furthermore, feathers of seabirds contained a greater contribution of lowerchlorinated congeners to their PCB profiles (12,13), although this was attributed to external contamination of PCBs on the feather surface. However, spreading preen gland oil on feathers could explain the similar congener composition (i.e., relative abundance in lower-chlorinated congeners) in preen gland oil and feathers.…”

“…Collection of droppings is noninvasive, but preservation and transport of the samples require cooling, which could be a problem in remote areas, especially in hot climates. Jaspers et al (12,13) evaluated the usefulness of feathers as a nondestructive biomonitoring tool. Feathers are easily carried and preserved.…”

“…Several methods have been proposed for taking samples from living birds, focusing on blood (10), droppings (11), feathers (12,13), and preen gland oil (14, 15). Finkelstein et al (10) measured PCBs in blood of seabirds sampled in Hawaii.…”

Assessment of contaminant levels and trophic relations at a World Heritage Site by measurements in a characteristic shorebird species

“…Levels in feathers might integrate contaminant loads over a relatively long period of time and thus be influenced by contaminant levels in areas used outside the breeding period (Jaspers et al, 2007). Blood levels, however, indicate contaminant levels during the breeding period, and thus reflect contaminant loads at distinct breeding sites.…”

“…Blood levels, however, indicate contaminant levels during the breeding period, and thus reflect contaminant loads at distinct breeding sites. We also examined the relationship between contaminant levels in feathers and those in blood, as suggested by Jaspers et al (2007Jaspers et al ( , 2008 for other bird species. (3) Trophic position of consumers such as birds and the origin of prey can be investigated by analysis of stable isotopes (Inger and Bearhop, 2008 Fry, 2006;Inger and Bearhop, 2008;Ceia et al, 2014).…”