Degradation of Plant Secondary Metabolites in Green Nest Material Used by Golden Eagles

Golden Eagles ( Aquila chrysaetos ) have been observed lining their nests with green nesting material (GNM) that is known to have high levels of plant secondary metabolites (PSMs). The ‘nest protection hypothesis’ predicts that use of GNM containing cytotoxic PSMs deters infestation of parasites. Parasitic infestations can have critical consequences for nest occupants which may range from dehydration to nest abandonment. To better understand if GNM has an anti-parasite function, we observed the stability of PSMs (specifically terpenes and phenolics) from selected plant species found in nests under different exposure levels to sunlight in a simulated nest environment. GNM was analyzed every two days to determine the rate of degradation of PSMs. We predicted a decrease in PSMs over time with terpenes degrading more quickly than phenolics due to volatility. The rate of degradation of PSMs will influence the anti-parasitic activity of GNM and potentially how frequently eagles must collect fresh GNM.