True cicadas (Cicadidae) as prey for the birds of the Western Palearctic: A review

Abstract

Background: True cicadas (Cicadidae) are large and temporarily abundant insects. Their availability may produce demographic and behavioural effects on bird populations, as happens with forest avifauna feeding on periodical cicadas in North America. In Europe, the Near East and North Africa, knowledge of cicada predation by birds is sparse. Methods: To help fill this gap, I consulted Cramp's Birds of the Western Palearctic, conducted a search of online databases and used search engines to generate a database of Western Palearctic birds known to eat cicadas. Results: A total of 105 species (16% of those occurring in the region) belonging to 13 orders, and comprising 20 of the 33 passerine families, were found to consume cicadas. I estimated that 69 of these bird species are known to consume cicadas within the limits of the Western Palearctic. Many terrestrial birds predate on cicadas, preferably on adults. Avian predators include cuckoos, owls, bee-eaters, woodpeckers, falcons, reed-warblers, larks, crows and jays, buntings, shrikes, pipits and wagtails, flycatchers and chats, tits, sparrows, leaf-warblers, starlings, warblers and thrushes, but also terns and gulls. Nymphs are consumed by some passerines, owls and herons. Cicadas can make up as much as 70% of food items delivered to nestlings. Analysis of stomach contents and neck collar samples are the most common methods used in diet studies. Conclusions: Available knowledge is biased towards species that have been more intensively studied, and often lack proper quantification of prey items. More studies about the relative importance of cicadas as prey for birds in the Western Palearctic are needed. I suggest using non-invasive studies based on pellets and droppings and prioritizing declining bird species.