Foraging behaviour and diet of American Oystercatchers in a Patagonian intertidal area affected by nutrient loading

Germán Oscar García; Juan Pablo Isacch; Agustina Gómez Laich; Mariano Albano; Marco Favero; Daniel Augusto Cardoni; Tomás Luppi; Oscar Iribarne

doi:10.1071/MU09066

RESEARCH ARTICLE

Foraging behaviour and diet of American Oystercatchers in a Patagonian intertidal area affected by nutrient loading

Germán Oscar García ^A ^B ^D , Juan Pablo Isacch ^A ^B , Agustina Gómez Laich ^A ^C , Mariano Albano ^A ^B , Marco Favero ^A ^B , Daniel Augusto Cardoni ^A ^B , Tomás Luppi ^A ^B and Oscar Iribarne ^A ^B

+ Author Affiliations

- Author Affiliations

^A Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Avenida Rivadavia 1917, C1033AAJ Buenos Aires, Argentina.

^B Departamento de Biología, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, Funes 3250, B7602AYJ Mar del Plata, Argentina.

^C Centro Nacional Patagónico (CENPAT) – CONICET, Boulevard Brown 2915, U9120ACD Puerto Madryn, Argentina.

^D Corresponding author. Email: garciagerman@argentina.com

Emu 110(2) 146-154 https://doi.org/10.1071/MU09066
Submitted: 28 July 2009 Accepted: 7 January 2010 Published: 26 May 2010

Abstract

Eutrophication increases the biomass of opportunistic green macroalgae that covers intertidal zones, and macroalgal blooms may affect the intertidal invertebrate community and predation of invertebrates by shorebirds. In San Antonio Bay, Argentina, eutrophication from the discharge of wastewater from a coastal town produces periodic macroalgal blooms. Our aim was to assess if macroalgal blooms affect the foraging behaviour and diet of the American Oystercatcher (Haematopus palliatus). A macroalgal transplant experiment was performed in order to evaluate how epifaunal species respond to a macroalgal canopy. The availability of prey for Oystercatchers, and their foraging behaviour and diet, were analysed in two paired channels with different nutrient loadings. Oystercatchers generally ate the most profitable prey and avoided prey with a profitability value lower than the mean rate of energy intake. During the macroalgal blooms, Oystercatchers avoided two prey species with high profitability values, shifting their foraging strategy and feeding onto a suboptimal prey but with a high encounter rate. Our results suggest that nutrient loadings and the macroalgal blooms that they generate have effects on the diet and foraging behaviour of Oystercatchers, which results in an increase of the average rate of energy intake of Oystercatchers foraging along the channel subject to a macroalgal bloom.

Acknowledgements

We thank P. Gómez Laich for language editing and P. Gonzalez for helpful comments in an earlier version. We appreciate the improvements in English language usage made by P. Lowther through the Association of Field Ornithologists’ program of editorial assistance. We thank M. Narvarte and R. González (from Instituto de Biologia Marina y Pesquera ‘Alte Storni’) for logistical assistance. This work was supported by grants from CONICET (PIP 2851) and Universidad Nacional de Mar del Plata.

References

Bachmann, S. , and Martínez, M. M. (1999). Feeding tactics of the American oystercatcher (Haematopus palliatus) on Mar Chiquita coastal lagoon, Argentina. Ornitologia Neotropical 10, 81–84.
BirdLife International. (2009). The BirdLife checklist of the birds of the world with conservation status and taxonomic sources. Version 2. Available at http://www.birdlife.org/datazone/species/index.html [Verified 29 April 2010].

Brawn, J. D. , Robinson, S. K. , and Thompson, F. R. (2001). The role of disturbance in the ecology and conservation of birds. Annual Review of Ecology and Systematics 32, 251–276.
| Crossref | GoogleScholarGoogle Scholar | Di Giacomo A. S. (2005). Áreas importantes para la conservación de las aves en la Provincia de Río Negro. In ‘Áreas Importantes para la Conservación de las Aves en la Argentina’. (Ed. A.S. Di Giacomo.) pp. 334–349. (Aves Argentinas and Asociación Ornitológica del Plata: Buenos Aires.)

Downes, B. J. , Lake, P. S. , Schreiber, E. S. G. , and Glaister, A. (1998). Habitat structure and regulation of local species diversity in a stony, upland stream. Ecological Monographs 68, 237–257.
| Crossref | GoogleScholarGoogle Scholar | Ivlev V. S. (1961). ‘Experimental Ecology of the Feeding of Fishes.’ (Yale University Press: New Haven, CT.)

Jones, C. G. , Lawton, J. H. , and Schachak, M. (1997). Positive and negative effects of organisms as physical ecosystem engineers. Ecology 78, 1946–1957.
| Crossref | GoogleScholarGoogle Scholar | López Lanús B. , Grilli P. , Coconier E. , Di Giacomo A. , and Banchs R. (2008). Categorización de las aves de la Argentina según su estado de conservación. Informe de Aves Argentinas/AOP y Secretaría de Ambiente y Desarrollo Sustentable Buenos Aires, Argentina. Talleres Gráficos Leograf SRL. Available at http://medioambiente.gov.ar/archivos/web/DFS/File/Categorizacion_de_las_Aves_de_la_Argentina_2008.pdf [Verified 29 April 2010].

Martin P. , and Bateson P. (1993). ‘Measuring behaviour, an introductory guide.’ (Cambridge University Press: Cambridge, UK.)

Meire, P. M. , and Ervynck, A. (1986). Are oystercatchers (Haematopus ostralegus) selecting the most profitable mussels (Mytilus edulis)? Animal Behaviour 34, 1427–1435.
| Crossref | GoogleScholarGoogle Scholar | Pickett S. T. A. (1989). Space-for-time substitution as an alternative to long-term studies. In ‘Long-term Studies in Ecology: Approaches and Alternatives’. (Ed. G.E. Likens.) pp. 110–135. (Springer-Verlag: New York.)

Raffaelli, D. G. , Limia, J. , Hull, S. , and Pont, S. (1991). Interactions between the amphipod Corophium volutator and macroalgal mats on estuarine mudflats. Journal of the Marine Biological Association of the United Kingdom 71, 899–908.
| Crossref | GoogleScholarGoogle Scholar | Shuterland W. J. , Ens B. , Goss-Custard J. D. , and Hulscher J. B. (1996). Specialization. In ‘The Oystercatcher, From Individuals to Populations’. (Ed. J. D. Goss-Custard.) pp. 56–76. (Oxford University Press: Oxford, UK.)

Stephens D. W. , and Krebs J. R. (1986). ‘Foraging Theory.’ (Princeton University Press: Princeton, NJ.)

Teichberg, M. , Fox, S. E. , Olsen, Y. S. , Valiela, I. , and Martinetto, P. , et al. (in press). Eutrophication and macroalgal blooms in temperate and tropical coastal waters: nutrient enrichment experiments with Ulva spp. Global Change Biology ,
Valiela I. (2006). ‘Global Coastal Change.’ (Blackwell Publishing: Malden, MA.)

Valiela, I. , McClelland, J. , Hauxwell, J. , Behr, P. J. , Hersh, D. , and Foreman, K. (1997). Macroalgal blooms in shallow estuaries: controls and ecophysiological and ecosystem consequences. Limnology and Oceanography 42, 1105–1118.
| Crossref | GoogleScholarGoogle Scholar | Van de Kam J. , Ens B. , Piersma T. , and Zwartz L. (2004). Food. In ‘Shorebirds: An Illustrated Behavioural Ecology’. pp. 147–230. (KNNV Publishers: Utrecht, The Netherlands.)

Whorff, J. S. , Whorff, L. L. , and Sweet, M. H. (1995). Spatial variation in an algal turf community with respect to substratum slope and wave height. Journal of the Marine Biological Association of the United Kingdom 75, 429–444.
| Crossref | GoogleScholarGoogle Scholar | Yorio P. , Frere E. , Gandini P. , and Harris G. (1998). ‘Atlas de la Distribución Reproductiva de Aves Marinas en el Litoral Patagónico Argentino.’ (Fundación Patagonia Natural and Wildlife Conservation Society: Buenos Aires.)

Zar J. H. (1999). ‘Biostatistical Analysis.’ (Prentice Hall Inc.: Englewood Cliffs, NJ.)

Foraging behaviour and diet of American Oystercatchers in a Patagonian intertidal area affected by nutrient loading

Abstract

Acknowledgements

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