The last meal: large insects predominate the diet of the European Roller Coracias garrulus prior to population extinction

摘要

Capsule: The diet of a European Roller Coracias garrulus population, approximately 10 years before its extinction, comprised of large-bodied orthopterans and coleopterans. Aims: To explore the diet composition of declining population of the European Roller. Methods: In 2005, 2006 and 2009, we monitored 18 nesting sites of the European Roller in southern Poland. Pellets and prey remain found in nest-holes were analysed. Results: In total, 1646 prey items were found. Orthoptera (60.4% of prey items) and Coleoptera (38.5%) predominated while vertebrates were caught rarely. Large-bodied species (orthopterans, bush-crickets, beetles Prionus coriarius and Cetonia aurata) including ground-dwellers (mole cricket, field crickets) constituted a substantial proportion of the diet. Conclusion: The results obtained show that, approximately 10 years before extinction of the local population in southern Poland, European Rollers preyed on large beetles and orthopterans, which is typical for that species. It seems that recent agriculture abandonment and natural succession may have reduced the abundance of these prey species and their availability for European Rollers and thus contribute to their extinction.