Dietary characterization of Savi s Warbler Locustaella luscinioides and Great Reed Warbler Acrocephalus rundinaceus in eastern Spain

Abstract

[EN] This research deals with two insectivorous reedbed-nesting songbirds, the Savi's Warbler Locustella luscinioides and the Great Reed Warbler Acrocephalus arundinaceus breeding at the Marjal de Pego-Oliva (Valencia-Alicante, Spain). Our aims were to study the diet and the prey selection of the two species and to assess the dietary differences between them. Diet composition has been assessed by examining samples off regurgitated food obtained using apomorphine as an emetic. Prey availability was estimated through standardized invertebrate sampling. The diet of the two warblers were significantly different and included arthropods belonging to the orders Araneida, Coleoptera, Hymenoptera, Hemiptera, Diptera, Mantodea and Orthoptera. The most represented prey were Araneida and Coleoptera in the diet of Savi s Warblers, and Hymenoptera and Coleoptera in the diet of Great Reed Warblers. Both species positively selected Araneida and Coleoptera and avoided Diptera, while for other arthropod taxa prey selection differed between the two warbler