Doi: https://doi.org/10.13157/arla.72.1.2025.sc2
Authors: Sara PUCHE GÓMEZ, Pablo PERALES PACHECO, Pilar GÓMEZ-RAMÍREZ, Francisco BOTELLA, José Antonio SÁNCHEZ-ZAPATA and Juan Manuel PÉREZ-GARCÍA
E-mail: sara.puche@hotmail.com
Published: Volume 72.1, January 2025. Pages 93-104.
Language: English
Keywords: breeding, Bubo bubo, nestlings, oryctolagus cuniculus, prey, raptor and South-eastern Spain
Summary:
Some bird species, particularly owls, store prey within their nests during the breeding season. Food storage has been explained by the need to buffer the environmental variability of resources available for the offspring. This study describes food stores of the Eurasian Eagle Owl Bubo bubo in the southeast of the Iberian Peninsula and evaluates which intrinsic and extrinsic factors influence their presence and composition. Between 2003 and 2021, we studied the presence, abundance, biomass and species richness of prey in food stores found in 318 nests. Stores occurred in 63.5% of nests and included 520 prey items belonging to 23 different species. The main prey species was the European Rabbit Oryctolagus cuniculus (71.43%). The greatest abundance of prey and biomass found in the stores occurred when the owlets were between 20 and 25 days old, that is when peak owlet growth occurs. Neither abundance nor biomass of prey in stores were related to brood size. Similarly, the frequency of food store occurrence in nests per year was unrelated to precipitation in the preceding months, which serves as a proxy of rabbit abundance. Globally these results support the hypothesis of that Eagle Owl parents adjust the stores according to when their owlets have their highest energy demands, irrespective of brood size and likely prey abundance. Food storage may help Eagle Owls to maximise their reproductive success in a semi-arid environment subject to high environmental variability.
Supplementary Material:
Downloadable 1
