DNA metabarcoding of nestling feces reveals provisioning of aquatic prey and resource partitioning among Neotropical migratory songbirds in a riparian habitat
- 417 Downloads
Riparian habitats are characterized by substantial flows of emergent aquatic insects that cross the stream-forest interface and provide an important source of prey for insectivorous birds. The increased availability of prey arising from aquatic subsidies attracts high densities of Neotropical migratory songbirds that are thought to exploit emergent aquatic insects as a nestling food resource; however, the prey preferences and diets of birds in these communities are only broadly understood. In this study, we utilized DNA metabarcoding to investigate the extent to which three syntopic species of migratory songbirds—Acadian Flycatcher, Louisiana Waterthrush, and Wood Thrush—breeding in Appalachian riparian habitats (Pennsylvania, USA) exploit and partition aquatic prey subsidies as a nestling food resource. Despite substantial differences in adult foraging strategies, nearly every nestling in this study consumed aquatic taxa, suggesting that aquatic subsidies are an important prey resource for Neotropical migrants nesting in riparian habitats. While our results revealed significant interspecific dietary niche divergence, the diets of Acadian Flycatcher and Wood Thrush nestlings were strikingly similar and exhibited significantly more overlap than expected. These results suggest that the dietary niches of Neotropical migrants with divergent foraging strategies may converge due to the opportunistic provisioning of non-limiting prey resources in riparian habitats. In addition to providing the first application of DNA metabarcoding to investigate diet in a community of Neotropical migrants, this study emphasizes the importance of aquatic subsidies in supporting breeding songbirds and improves our understanding of how anthropogenic disturbances to riparian habitats may negatively impact long-term avian conservation.
KeywordsAcadian flycatcher Diet Louisiana waterthrush Resource subsidies Wood thrush
We thank the Carnegie Museum of Natural History, Cokie Lindsay, and Dr. John Wenzel for coordinating access to study sites and providing accommodations at Powdermill Nature Reserve. We thank Eduardo Anaya, Thomas Cordray, Danilo Mejía, Michael Miles, Maria Paulino, and Youstina Seliman for field assistance and the Genomics Facility of the Biotechnology Resource Center at Cornell University (Ithaca, NY) for conducting Illumina sequencing. This research was supported by grants from the American Ornithological Society (formerly the American Ornithologists’ Union), Carnegie Museum of Natural History, National Aviary, and National Science Foundation (DEB-1349870 to Tim Nuttle). We thank the Bayer School of Natural and Environmental Sciences at Duquesne University for supporting undergraduate field technicians through a research fellowship. We thank Powdermill Nature Reserve (Carnegie Museum of Natural History) for supporting B.K.T. through the Rea Research Fellowship and the Bayer School of Natural and Environmental Sciences (Duquesne University) for supporting B.K.T. through a teaching assistantship and the Bayer Graduate Research Fellowship.
Author contribution statement
B.K.T., T.N., B.A.P., and S.C.L. collectively conceived and designed this study as an extension of S.C.L.’s long-term research on Louisiana Waterthrush. B.K.T. and B.D.H. conducted the fieldwork (with guidance from T.N., B.A.P., and S.C.L.); B.K.T. developed the field and laboratory protocols, conducted molecular work (with B.D.H.), performed statistical analyses (with N.L.B.), and wrote the manuscript in the laboratory of B.A.P.
Compliance with ethical standards
All applicable institutional and/or national guidelines for the care and use of animals were followed.
- Anderson MJ (2001) A new method for non-parametric multivariate analysis of variance. Austral Ecol 26:32–46Google Scholar
- Barbour MT, Gerritsen J, Snyder BD, Stribling JB (1999) Rapid bioassessment protocols for use in streams and wadeable rivers: periphyton, benthic macroinvertebrates and fish, second edition. EPA 841-B-99-002. U.S. Environmental Protection Agency Office of Water, Washington, DC, USAGoogle Scholar
- Biermann GC, Sealy SG (1982) Parental feeding of nestling Yellow Warblers in relation to brood size and prey availability. Auk 99:332–341Google Scholar
- Blankenberg D et al (2010) Galaxy: a web-based genome analysis tool for experimentalists. Curr Protocols Mol Biol Supplement 19.10.1–19.10.21. Chapter 19. https://doi.org/10.1002/0471142727.mb1910s89
- Drohan PJ, Brittingham M, Bishop J, Yoder K (2012) Early trends in landcover change and forest fragmentation due to shale-gas development in Pennsylvania: a potential outcome for the northcentral Appalachians. Environ Manage 49:1061–1075. https://doi.org/10.1007/s00267-012-9841-6 CrossRefPubMedGoogle Scholar
- Evans M, Gow E, Roth RR, Johnson MS, Underwood TJ (2011) Wood Thrush (Hylocichla mustelina). In: Rodewald PG (ed) The Birds of North America. Cornell Lab of Ornithology, IthacaGoogle Scholar
- Gotelli NJ, Hart EM, Ellison AM (2015) EcoSimR: Null model analysis for ecological data. R package version 0.1.0. http://github.com/gotellilab/EcoSimR
- Hodges MF, Krementz DG (1996) Neotropical migratory breeding bird communities in riparian forests of different widths along the Altamaha River, Georgia. Wilson Bull 108:496–506Google Scholar
- Hsieh TC, Ma KH, Chao A (2016) iNEXT: iNterpolation and EXTrapolation for species diversity. R package version 2.0.12. http://chao.stat.nthu.edu.tw/blog/software-download/
- Knopf FL, Johnson RR, Rich T, Samson FB, Szaro RC (1988) Conservation of riparian ecosystems in the United States. Wilson Bull 100:272–284Google Scholar
- Levins R (1968) Evolution in changing environments. Princeton University Press, PrincetonGoogle Scholar
- Mattsson BJ, Master TL, Mulvihill RS, Robinson DW (2009) Louisiana Waterthrush (Parkesia motacilla). In: Rodewald PG (ed) The Birds of North America Online. Cornell Lab of Ornithology, IthacaGoogle Scholar
- Merritt RW, Cummins KW (2008) An introduction to the aquatic insects of North America, 4th edn. Kendall/Hunt, DubuqueGoogle Scholar
- Nakano S, Miyasaka H, Kuhara N (1999) Terrestrial-aquatic linkages: riparian arthropod inputs alter trophic cascades in a stream food web. Ecology 80:2435–2441Google Scholar
- Oksanen J et al. (2017) vegan: Community Ecology Package. R package version 2.4.2. https://cran.r-project.org/package=vegan
- Rappole JH, McDonald MV (1994) Cause and effect in population declines of migratory birds. Auk 111:652–660Google Scholar
- Rosenberg KV, Cooper RJ (1990) Approaches to avian diet analysis. Stud Avian Biol 80–90Google Scholar
- Rosenberg KV, Ohmart RD, Anderson BW (1982) Community organization of riparian breeding birds: response to an annual resource peak. Auk 99:260–274Google Scholar
- Sauer JR, Hines JE, Fallon JE, Pardieck KL, Ziolkowski DJ, Link WA (2014) The North American Breeding Bird Survey, results and analysis 1966–2015. Version 2.07.2017, 01.30.2015 edn. USGS Patuxent Wildlife Research Center, LaurelGoogle Scholar
- Whitehead DR, Taylor T (2002) Acadian Flycatcher (Empidonax virescens). In: Rodewald PG (ed) The Birds of North America. Cornell Lab of Ornithology, IthacaGoogle Scholar
- Wiens JA (1977) On competition and variable environments: populations may experience “ecological crunches” in variable climates, nullifying the assumptions of competition theory and limiting the usefulness of short-term studies of population patterns. Am Sci 65:590–597Google Scholar