Gutierrez M.C. (1988) Winter foraging behaviour of Blackcap and Sardinian Warbler in a Mediterranean scrubland. ARDEA 76 (1): 107-110

The foraging behaviour and habitat selection of two species of sylviid warblers (Blackcap Sylvia atricapilla and Sardinian Warbler S. melanocaphala) were studied in a Mediterranean scrubland winter quarter, southern Spain. We have considered four foraging techniques and six structural layers in the habitat. The two species overlap extensively in foraging techniques but occupy different vegetation layers during the winter season. Both species predominantly use a Gleaning technique (Arboreal and Ground gleaning), showing strong habitat segregation: Blackcaps mostly forage within the tree canopies, while Sardinian Warblers preferred the scrub layers. The data also suggest a selective use of different plant species for foraging: wild olive trees by Blackcaps and P. lentisucus by Sardinian Warblers. Our results suggest that reduction of competition in these ecologically related species has been achieved by means of habitat segregation more than by dissimilar use of foraging techniques. These findings are in agreement with earlier results obtained during the breeding season (e.g. Cody & Walter 1976) and suggest the existence of a similar pattern of interspecific interactions across the Palaearctic range of distribution of the two warbler species.