When Toxicity is Not Enough: Review and New Data on Blister Beetle (Coleoptera, Meloidae) Predation by Shrikes

Abstract

Shrikes from the genus Lanius are generalists in terms of diet, even consuming highly toxic species, as blister beetles (Coleoptera, Meloidae). Despite the fact that regular predation on these coleopterans have never been described both in recent and historical literature, birds stand out as one of the groups to most often prey upon these insects. In the Old World, records of shrikes preying on oil-beetles -most of them treated as anecdotal -have been published since the 19th century. However, despite being repetitive, no review or in-depth study of this behavior has been conducted. After a literature study and new data collected in the Iberian Peninsula, it seems an extended behaviour within the clade. As could be observed in a high number of cases, birds even apply a specific technique, selecting specific body parts to kill the beetle, more sclerotic and presumably less toxic. In some cases, strict predation has been demonstrated. To date, at least six different shrike species -Red-backed Shrike Lanius collurio, Great Grey Shrike L. excubitor, Iberian Grey Shrike L. meridionalis, Loggerhead Shrike L. ludovicianus, Lesser Grey Shrike L. minor, and Woodchat Shrike L. senator -have been found to show signs of preying on at least nine Meloidae species throughout Europe, North Africa and North America, constituting a line of research that should be studied in greater detail.