Figure 2. Stable carbon (δ¹³C) and nitrogen (δ¹⁵N) isotope values (‰) in Bonelli’s eagle nestlings and their main prey.

Prey isotopic values were corrected for trophic discrimination factors (i.e. 2.1 and 2.7‰ for δ¹³C and δ¹⁵N, respectively; [59]). Single data points represent nestlings of each territory-year, with different symbols for France, Catalonia and Andalusia. Prey categories (mean ±95% SD) included: European rabbits, red-legged partridges, wood pigeons, domestic pigeons wildly foraging in crops (1), domestic pigeons from dovecotes and fed with corn (2), passerines, Eurasian red squirrels, and ocellated lizards (see figure legend).