INVESTIGADORES
GARCIA german oscar
artículos
Título:
Cambios en la interacción de depredación entre la Gaviota Cocinera (Larus dominicanus) y ls gaviotines Real (Thalasseus maximus) y Pico Amarillo (Thalasseus sandvicensis euygnathus) en Punta León, Argentina
Autor/es:
SILVA LAURA; GATTO ALEJANDRO; GARCÍA GERMÁN OSCAR; YORIO PABLO MARTÍN
Revista:
ORNITOLOGIA NEOTROPICAL
Editorial:
NEOTROPICAL ORNITHOLOGICAL SOC
Referencias:
Año: 2010 vol. 21 p. 479 - 487
ISSN:
1075-4377
Resumen:
We studied the predation by Kelp gull (Larus dominicanus) upon Royal and Cayenne terns (Thalasseus maximus and T. sandvicensis euygnathus, respectively) at the Punta León Protected Area, Argentina, during the 2005 and 2006 breeding seasons to assess changes in the predator-prey interaction with respect to that observed at the same location in the early 1990’s. Similar to previous evaluations, the Kelp gull was responsible of all predation events on both tern species. During 2006, the predation rate on eggs was 0.01 ± 0.003 eggs/hour/nest, similar to that recorded in 1991 and 1992 and slightly lower that that recorded in 1990. All cases (n = 71) occurred on peripheral nests. In contrast to previous studies, we also recorded predation on chicks of both tern species. During 2005 and 2006 we recorded 43 and 41 predation attempts on chicks, respectively, totaling 18 and 9 successful events, respectively. In 2005, 88% of attempts were on chicks located at the periphery of nest groups, while in 2006 63.5% were on chicks at these locations and the remaining 36.5% on those at the periphery of “crèches”. None of the predation attempts on chicks in “crèches” was successful. The relationship between predation events and the location of prey within the mixed-species colony shows the importance of the spatial structure in the determination of predator-prey interactions in seabird colonies. Our results show that the Kelp gull is the main predator of Royal and Cayenne tern eggs at the Punta León colony, with predation rates similar to those recorded in previous studies. However, the predation impact of Kelp gulls has extended in recent years to the chick stage of both tern species.