Register      Login
Emu Emu Society
Journal of BirdLife Australia
Shopping Cart: ( empty )
You are here: Home > Journals > MU > MU08025
RESEARCH ARTICLE
Contents Vol 109(1)

Provisioning of mates and chicks by Cayenne and Royal Terns: resource partitioning in northern Patagonia, Argentina

Alejandro J. Gatto A C and Pablo Yorio A B
+ Author Affiliations
- Author Affiliations

A Centro Nacional Patagónico, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Boulevard Brown 2915, U9120ACV, Puerto Madryn, Chubut, Argentina.

B Wildlife Conservation Society, Virrey del Pino 2632, P 19, Dpto. B, Ciudad de Buenos Aires, Argentina. Email: yorio@cenpat.edu.ar

C Corresponding author. Email: alegatto@cenpat.edu.ar

Emu 109(1) 49-55 https://doi.org/10.1071/MU08025
Submitted: 14 May 2008  Accepted: 28 November 2008   Published: 5 March 2009

Abstract

Cayenne (Thalasseus sandvicensis eurygnathus) and Royal Terns (Thalasseus maximus) breed in mixed colonies in Argentina. This paper presents the first detailed information on their breeding diet and assesses differences and overlap between species in the type and size of prey. During 2004 and 2005, observations of prey delivered to mates and chicks were carried out at Punta León, Patagonia. The diet of Cayenne and Royal Terns comprised nine and 10 prey species respectively. Fish comprised >99% of the prey of both species of tern in the two study years. Both species had a fairly specialised diet based on pelagic schooling fish, mostly Argentine Anchovy (Engraulis anchoita) and two species of silversides (Odontesthes spp.). Despite observed overlap in trophic resources, our results showed that Argentine Anchovy was the main prey for Royal Terns, whereas the two species of silversides together with Anchovy comprised the bulk of the diet for Cayenne Terns. Fish delivered by Cayenne Terns were significantly smaller than those by Royal Terns. Results suggested that both type and size of prey may be important factors permitting food partitioning between the two species of tern during the breeding season.

Additional keywords: Argentine Anchovy, chick-feeding, food-partitioning, mate-feeding.


Acknowledgements

Research was supported by the Wildlife Conservation Society, The Waterbird Society 2005 Nisbet Research Grant, and Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET). We thank Germán García, Luján Villanueva Gomila, Walter Svagelj, Nora Lisnizer, Sergio Sanz and Julio Rúa for field assistance; Bernabé Urrutia and people from Estancias ‘El Pedral’ and ‘Bahía Cracker’ for logistical support; Kees Hulsman and Flavio Quintana for helpful advice during field work; and Leo Venerus, Martín García Azorey, and Walter Svagelj for advice with model analyses. Atila Gosztonyi helped in the determination of fish prey species. We thank Organismo Provincial de Turismo of Chubut for the permits to work at Punta León Reserve. Binoculars used in 2005 were provided by Optics for the Tropics. We thank the North American Ornithological Societies Travel Award, Aluar and Fundación Patagonia Natural for support.


References

Agresti A. (2002). ‘Categorical Data Analysis.’ (Wiley: Hoboken, NJ.)

Ashmole N. P. , and Ashmole M. J. (1967). Comparative feeding ecology of seabirds of a tropical oceanic island. In ‘Bulletin of the Peabody Museum of Natural History’, vol. 24. (Yale University, New Haven, CT.)

Aygen, D. , and Emslie, S. D. (2006). Royal diet (Sterna maxima) chick diet at Fisherman Island National Wildlife Refuge, Virginia. Waterbirds 29, 395–400.
| Crossref | GoogleScholarGoogle Scholar | Buckley P. A. , and Buckley F. G. (2002). Royal Tern (Sterna maxima). In ‘The Birds of North America Online’. (Ed. A. Poole.) No. 700. (Cornell Lab of Ornithology: Ithaca, NY.) Available at http://bna.birds.cornell.edu/bna/species/700 [Verified 24 February 2009].

Burger, J. (1985). Advantages and disadvantages of mixed-species colonies of seabirds. Proceedings of the International Ornithological Congress 18, 905–918.
Burnham K. P. , and Anderson D. R. (2002). ‘Model Selection and Multimodel Inference: A Practical Information Theoretic Approach.’ (Springer-Verlag: New York.)

Comitê Brasileiro de Registros Ornitológicos (2006). Listas das aves do Brasil. Versão 10 February 2006. (Comitê Brasileiro de Registros Ornitológicos: São Paulo, Brazil.) Available at http://www.cbro.org.br/CBRO/listabr.htm [Verified 6 July 2007].

Coulson J. C. (2002). Colonial breeding in seabirds. In ‘Biology of Marine Birds’. (Eds E. A. Schreiber and J. Burger.) pp. 87–113. (CRC Press: Boca Raton, FL.)

Crawford, R. J. M. (2003). Influence of food on numbers breeding, colony size and fidelity to localities of Swift Terns in South Africa’s Western Cape, 1987–2000. Waterbirds 26, 44–53.
| Crossref | GoogleScholarGoogle Scholar | Faraway J. J. (2006). ‘Extending the Linear Model in R: Generalized Linear, Mixed Effects and Nonparametric Regression Models.’ (Chapman & Hall and CRC Press: Boca Raton, FL.)

Fasola, M. , Bogliani, G. , Saino, N. , and Canova, L. (1989). Foraging, feeding and time-activity niches of eight species of breeding seabirds in the coastal wetlands of the Adriatic Sea. Bollettino di Zoologia 56, 61–72.
Gochfeld M. , and Burger J. (1996). Family Sternidae (Terns). In ‘Handbook of the Birds of the World. Vol. 3: Hoatzin to Auks’. (Eds J. Del Hoyo, A. Elliott and J. Sargatal.) pp. 624–667. (Lynx Edicions: Barcelona.)

Gotelli N. J. , and Entsminger G. L. (2001). ‘EcoSim: Null Models Software for Ecology.’ Version 7.72. (Acquired Intelligence Inc. & Kesey-Bear: Jericho, VT.) Available at http://www.garyentsminger.com/ecosim/ecosim.htm [Verified 6 July 2007].

Hulsman K. (1988). The structure of seabird communities: an example from Australian waters. In ‘Seabirds and Other Marine Vertebrates: Competition, Predation, and Other Interactions’. (Ed. J. Burger). pp. 59–91. (Columbia University Press: New York.)

Krebs C. J. (1999). ‘Ecological Methodology.’ (Benjamin Cummings/Addison-Wesley Educational Publishers Inc.: Menlo Park, CA.)

McGinnis, T. W. , and Emslie, S. D. (2001). The foraging ecology of Royal and Sandwich Terns in North Carolina, USA. Waterbirds 24, 361–370.
Nisbet I. C. T. (1977). Courtship-feeding and clutch size in Common Terns Sterna hirundo. In ‘Evolutionary Ecology’. (Eds B. Stonehouse and C. Perrins.) pp. 101–109. (MacMillan: London.)

Pearson, T. H. (1968). The feeding biology of seabirds species breeding on Farne Islands, Northumberland. Journal of Animal Ecology 37, 521–548.
| Crossref | GoogleScholarGoogle Scholar | R Development Core Team (2008). ‘R: A Language and Environment for Statistical Computing.’ (R Foundation for Statistical Computing: Vienna, Austria.) Available at http://www.R-project.org [Verified 10 February 2009].

Ridoux, V. (1994). The diets and dietary segregation of seabirds at the subantarctic Crozet Islands. Marine Ornithology 22, 1–192.
Shealer D. (1999). Sandwich Tern (Sterna sandvicencis). In ‘The Birds of North America Online’. (Ed. A. Poole.) No. 405. (Cornell Lab of Ornithology: Ithaca, NY.) Available at http://bna.birds.cornell.edu/bna/species/405 [Verified 24 February 2009].

Silva Rodriguez, M. P. , Favero, M. , Berón, M. P. , Mariano-Jelicich, R. , and Mauco, L. (2005). Ecología y conservación de aves marinas que utilizan el litoral bonaerense como área de invernada. Hornero 20, 111–130.
Wiens J. A. (1989). ‘The Ecology of Bird Communities. Vol. 1. Foundations and Patterns.’ (Cambridge University Press: Cambridge, UK.)

Yorio, P. (2005). Estado poblacional y conservación de gaviotines y skúas en el litoral Argentino. Hornero 20, 75–93.
Yorio P. , Frere E. , Gandini P. , and Harris G. (Eds) (1998). ‘Atlas de la Distribución Reproductiva de Aves Marinas en el Litoral Patagónico Argentino. Plan de Manejo Integrado de la Zona Costera Patagónica.’ (Fundación Patagonia Natural, Wildlife Conservation Society and Instituto Salesiano de Artes Gráficas: Buenos Aires, Argentina.)