Contribution of emergent aquatic insects to the trophic variation of tropical birds and bats

Author(s)

Recalde, Fatima C. ^{[1, 2]} ; Breviglieri, Crasso P. B. ^[3] ; Kersch-Becker, Monica F. ^[4] ; Romero, Gustavo Q. ^[3]

Affiliation

^[1] State Univ Campinas UNICAMP, Inst Biol, Programa Posgrad Ecol, BR-13083862 Campinas - Brazil

^[2] Univ Autonoma Encarnacion UNAE, Hlth Sci Fac, Encarnacion 070118 - Paraguay

^[3] State Univ Campinas UNICAMP, Inst Biol, Dept Anim Biol, BR-13083862 Campinas - Brazil

^[4] Univ Alabama, Dept Biol Sci, Tuscaloosa, AL 35487 - USA

• Document type: Journal article
• Source: FOOD WEBS; v. 29, DEC 2021.
• Web of Science Citations: 0

Abstract

Food webs are spatially connected by cross-ecosystem fluxes of resources, especially in aquatic-terrestrial boundaries. Generalist consumers are often supported by allochthonous resources, which can influence their density, biomass, and distribution. In this study, we investigated the influence of allochthonous aquatic resources on the foraging activity of bats (by ultrasound emissions) and richness of birds (by birdsong records). We also used stable isotope analysis of delta 13C and delta 15N to determine their diet and trophic space using bayesian Standard Ellipse Area (SEA). We evaluated these responses in near-site (0-1 m from stream margin) and far-site (200 m from stream margin) from six streams in the Atlantic and the Amazon Forest. Foraging activity of bats and richness of Amazonian birds were higher in near-sites compared to far-sites, while Atlantic bird richness was higher in far-sites. We found that emergent aquatic insects and spiders contributed to 46-45% and 49-36% of the diet of insectivorous bats and birds, respectively, regardless of the distance from streams. In Atlantic Forest, SEA of both birds and bats were not compared between plots because of the low sample size. In Amazon Forest, the far-site trophic space of birds showed a higher delta 15N position in the bi-plot. These findings suggest that allochthonous resources are important for areas near and far from streams. Our study underscores the importance of preserving both near and adjacent far habitats in the maintenance of trophic interaction involving flying vertebrates and highlights the interdependence of those areas via allochthonous subsidies. (AU)

• FAPESP's process: 19/08474-8 - Freshwater ecosystems under climate change: impacts across multiple levels of organisation
• Grantee: Gustavo Quevedo Romero
• Support Opportunities: Research Program on Global Climate Change - Thematic Grants
• FAPESP's process: 18/12225-0 - Unifying environmental and spatial determinants of food web structure across spatial scales
• Grantee: Gustavo Quevedo Romero
• Support Opportunities: BIOTA-FAPESP Program - Regular Research Grants
• FAPESP's process: 17/09052-4 - Influence of latitude and aquatic subsidies on niche breadth and structure of terrestrial communities
• Grantee: Gustavo Quevedo Romero
• Support Opportunities: Regular Research Grants