Arthropods associated with nests of Cacicus sp. and Psarocolius sp. (Passerida: Icteridae) in varzea forest near the meeting of the rivers Negro and Solimões (Central Amazonia, Brazil) at high water

Abstract

We analysed the arthropod fauna from nine nests of Cacicus sp. and nine nests of Psarocolius sp. (Passerida: Icteridae), in the varzea forest of Central Amazonia, Brazil, during high water, establishing these nests as one of the probable refuges for several arthropods performing vertical migration during periods of flooding and high water, besides discussing the role of these arthropods in the nests. We also evaluate the effectiveness of the extraction of arthropods from nests using an apparatus based on the Berlese–Tullgren funnel. We obtained 15,128 arthropods from three subphyla, five classes and 16 orders. The nests were shown as complex ecosystems sheltering groups from different functional and trophic categories and revealed striking differences from those of terra firma, remarkably in Blattaria, Arachnida and Pseudoscorpiones. The increasing volume of the funnel and time of heat exposure was shown to be appropriate for extraction of the arthropods from the bulky nests of these birds.

Keywords:

• birds' nests
• inundation forests
• nest fauna
• survival strategies
• vertical migration

Acknowledgements

This paper forms part of the master degree studies of the first author presented to the Graduate Program in Entomology, of the convention between INPA and UFAM. The authors thank CNPq and INPA, that made possible the accomplishment of this study; the Instituto Brasileiro de Meio Ambiente (IBAMA), for supplying the collection license (license 85/2002); Mr. Luis de Sales Aquino, INPA, for tireless fieldwork during the collection of the nests; MSc. Rafael Augusto Pinheiro de Freitas Silva, INPA, for carefully reviewing the manuscript, for improving the English text and for helping on the preparation of the plates; Mr. Konstantinos Ribeiro, INPA, for improving the English text; special thanks is directed to Dr. Claudio Ruy Vasconcelos da Fonseca, INPA, who greatly encouraged the work of the first author. We thank also the specialists for the identification of the arthropods, the groups of study in parentheses: Dra. Nair Otaviano Aguiar, UFAM (Pseudoscorpiones); MSc. Adalberto Varela Freire, UFRN (immature of Lepidoptera); Mr. José Maria Vilhena, INPA (genera of Formicidae); MSc. Maria Carmozina de Araújo, INPA (Blattaria). Photo's by F.B.P. Gouveia.