Affordable Access

Publisher Website

Quantitative meta-analysis reveals no association between mercury contamination and body condition in birds.

  • Carravieri, Alice1
  • Vincze, Orsolya2, 3
  • Bustamante, Paco1, 4
  • Ackerman, Joshua T5
  • Adams, Evan M6
  • Angelier, Frédéric7
  • Chastel, Olivier7
  • Cherel, Yves7
  • Gilg, Olivier8, 9
  • Golubova, Elena10
  • Kitaysky, Alexander11
  • Luff, Katelyn12
  • Seewagen, Chad L13
  • Strøm, Hallvard14
  • Will, Alexis P11
  • Yannic, Glenn9, 15
  • Giraudeau, Mathieu1, 16
  • Fort, Jérôme1
  • 1 Littoral Environnement et Sociétés (LIENSs), UMR 7266 CNRS-La Rochelle Université, 2 rue Olympe de Gouges, La Rochelle, 17000, France. , (France)
  • 2 Centre for Ecological Research-DRI, Institute of Aquatic Ecology, 18/C Bem tér, Debrecen, 4026, Hungary. , (Hungary)
  • 3 Evolutionary Ecology Group, Hungarian Department of Biology and Ecology, Babeş-Bolyai University, 5-7 Clinicilor street, Cluj-Napoca, 400006, Romania. , (Oman)
  • 4 Institut Universitaire de France (IUF), 1 rue Descartes, Paris, 75005, France. , (France)
  • 5 U.S. Geological Survey, Western Ecological Research Center, Dixon Field Station, 800 Business Park Drive, Suite D, Dixon, CA, 95620, U.S.A.
  • 6 Biodiversity Research Institute, 276 Canco Road, Portland, ME, 04103, U.S.A.
  • 7 Centre d'Etudes Biologiques de Chizé (CEBC), UMR 7372 CNRS-La Rochelle Université, 405 Route de Prissé la Charrière, Villiers-en-Bois, 79360, France. , (France)
  • 8 UMR 6249 CNRS-Chrono-environnement, Université de Bourgogne Franche-Comté, 16 route de Gray, Besançon, 25000, France. , (France)
  • 9 Groupe de Recherche en Ecologie Arctique (GREA), 16 rue de Vernot, Francheville, 21440, France. , (France)
  • 10 Institute of Biological Problems of the North, Russian Academy of Sciences, Portovaya Str., 18, Magadan, RU-685000, Russia.
  • 11 Institute of Arctic Biology, University of Alaska Fairbanks, 2140 Koyukuk Drive, Fairbanks, AK, 99775, U.S.A.
  • 12 Department of Biology, University of Saskatchewan, 112 Science Place, Saskatoon, SK, S7N 5E2, Canada. , (Canada)
  • 13 Great Hollow Nature Preserve and Ecological Research Center, 225 State Route 37, New Fairfield, CT, 06812, U.S.A.
  • 14 Norwegian Polar Institute, Fram Centre, Tromsø, NO-9296, Norway. , (Norway)
  • 15 UMR 5553 CNRS-Université Grenoble Alpes, Université Savoie Mont Blanc, 2233 Rue de la Piscine, Saint-Martin d'Hères, Grenoble, 38000, France. , (France)
  • 16 Centre de Recherches en Écologie et en Évolution de la Santé (CREES), MIVEGEC, UMR IRD 224-CNRS 5290-Université de Montpellier, Domaine La Valette, 900 rue Breton, Montpellier, 34090, France. , (France)
Published Article
Biological reviews of the Cambridge Philosophical Society
Publication Date
Aug 01, 2022
DOI: 10.1111/brv.12840
PMID: 35174617


Mercury contamination is a major threat to the global environment, and is still increasing in some regions despite international regulations. The methylated form of mercury is hazardous to biota, yet its sublethal effects are difficult to detect in wildlife. Body condition can vary in response to stressors, but previous studies have shown mixed effects of mercury on body condition in wildlife. Using birds as study organisms, we provide the first quantitative synthesis of the effect of mercury on body condition in animals. In addition, we explored the influence of intrinsic, extrinsic and methodological factors potentially explaining cross-study heterogeneity in results. We considered experimental and correlative studies carried out in adult birds and chicks, and mercury exposure inferred from blood and feathers. Most experimental investigations (90%) showed a significant relationship between mercury concentrations and body condition. Experimental exposure to mercury disrupted nutrient (fat) metabolism, metabolic rates, and food intake, resulting in either positive or negative associations with body condition. Correlative studies also showed either positive or negative associations, of which only 14% were statistically significant. Therefore, the overall effect of mercury concentrations on body condition was null in both experimental (estimate ± SE = 0.262 ± 0.309, 20 effect sizes, five species) and correlative studies (-0.011 ± 0.020, 315 effect sizes, 145 species). The single and interactive effects of age class and tissue type were accounted for in meta-analytic models of the correlative data set, since chicks and adults, as well as blood and feathers, are known to behave differently in terms of mercury accumulation and health effects. Of the 15 moderators tested, only wintering status explained cross-study heterogeneity in the correlative data set: free-ranging wintering birds were more likely to show a negative association between mercury and body condition. However, wintering effect sizes were limited to passerines, further studies should thus confirm this trend in other taxa. Collectively, our results suggest that (i) effects of mercury on body condition are weak and mostly detectable under controlled conditions, and (ii) body condition indices are unreliable indicators of mercury sublethal effects in the wild. Food availability, feeding rates and other sources of variation that are challenging to quantify likely confound the association between mercury and body condition in natura. Future studies could explore the metabolic effects of mercury further using designs that allow for the estimation and/or manipulation of food intake in both wild and captive birds, especially in under-represented life-history stages such as migration and overwintering. © 2022 Cambridge Philosophical Society.

Report this publication


Seen <100 times