Stomach-flushing for diet analysis in anurans: an improved protocol evaluated in a case study in Araucaria forests, southern Brazil*

Abstract

Stomach-flushing is a gentle treatment in analysing the diet of vertebrates. We applied this method in the study of seasonal nutrition of anurans of 15 species at an Araucaria forest habitat on the Serra Geral of Rio Grande do Sul, Brazil. Over 500 frogs and toads of different body size were handled in order to evaluate an improved protocol without narcosis using soft infusion tubes in order to avoid negative effects of the flushing procedure. The specimens were treated soon after capture and then returned to the sampling sites. Our results are discussed with reference to the few studies on stomach flushing in amphibians. The improved technique is recommended to avoid killing of numerous animals for nutritional studies, in particular because of the worldwide threatening of amphibian populations.

Keywords:

• Diet
• stomach-flushing
• Amphibia
• Anura
• biodiversity, Araucaria forest
• Brazil

Acknowledgments

This research was performed with the long-term cooperation between the University of Tübingen and the PUCRS, Porto Alegre, RS, Brazil. We would like to thank the IMA, in particular Jorge A. Villwock, and the MCT, especially Marcos Di-Bernardo, for valuable support. We are grateful to Paul Müller, David Wake and Anne Zillikens for constructive comments on the manuscript.

Notes

* Part of the projects DLR-BMBF 01LT0011/7 ‘Araucaria forest’ and DLR/IB-FAPERGS ‘Subsidios para o diagnóstico ambiental do Planalto das Araucárias’.

Additional information

Notes on contributors

Mirco Solé

* Part of the projects DLR-BMBF 01LT0011/7 ‘Araucaria forest’ and DLR/IB-FAPERGS ‘Subsidios para o diagnóstico ambiental do Planalto das Araucárias’.