Temporal changes in metal concentrations in Andean condor feathers: a potential influence of volcanic activity.

Geothermal activities (e.g., volcanic eruptions) represent one of the most important natural sources of metal emissions (heavy metals and metalloids). They can be one of the main risks for the ecosystems in regions like North of Argentiniean Patagonia, a sparsely populated area, close to an extensive network of active volcanoes on the Andes Range. The 2011 eruption of the Puyehue-Cordon Caulle volcanic complex (PCCVC) has been the largest volcanic event of the last decades. The effects of exposure to ashes on wildlife and humans have been sparsely studied, and only one biomonitoring study has used higher trophic species. The exposure to metals of the species in Patagonia has been poorly studied. The main objectives of our study were to assess metal screening and to evaluate a possible relation between the levels of metals in the Andean condor (Vultur gryphus) population and the volcanic activity of the area. We investigated the effects of the eruption of the PCCVC in 2011, using samples of molt primary feathers of the Andean condor, collected in nine roosts around Bariloche, Argentina (maximum distance 85 km). Data available suggest the molt of the primary feathers of the Andean condor has a duration of 6 years. We carried out sampling before (2007, 2009) and after (2017) the volcanic eruption (2011). The feathers sampled in 2017 should have been developed in 2011-2012, reflecting the environmental situation of the period immediately following the eruption of the PCCVC. For the first time, we have screened metals in 48 molted primary feathers of Andean condor, showing the levels of 9 metals and metalloids (Si, Cr, Cu, Zn, As, Se, Cd, Pb, Hg). Si, Zn, As, and Cd showed higher levels in the feathers sampled after the eruption. The levels of Cr and Pb (although apparently not related to the volcanic eruption) in some samples are compatible with potential adverse effects in living organisms. The screening results represent an important database (the first for this species) that can be used in in future studies for comparative purposes. HIGHLIGHTS: •We present the first database of metals in condor feathers, which may be useful for future studies. •Volcanic eruptions might represent an important source of metal and metalloid emissions in this area. •The Andean condor from Argentine Patagonia could be affected by volcanic activity in the area. •Andean condor feathers may be good biomonitoring units of this contamination. •Pb pollution does not seem to be related to the volcano's eruption.