CESIMAR - CENPAT   25625
CENTRO PARA EL ESTUDIO DE SISTEMAS MARINOS
Unidad Ejecutora - UE
artículos
Título:
Trophic interactions between the Kelp Gull ( Larus dominicanus ) and Royal and Cayenne terns ( Thalasseus maximus maximus and Thalasseus sandvicensis eurygnathus , respectively) in a human-modified environment
Autor/es:
MARINAO, CRISTIAN; SUÁREZ, NICOLÁS; YORIO, PABLO
Revista:
CANADIAN JOURNAL OF ZOOLOGY
Editorial:
NATL RESEARCH COUNCIL CANADA-N R C RESEARCH PRESS
Referencias:
Año: 2019 vol. 97 p. 904 - 913
ISSN:
0008-4301
Resumen:
Many closelyrelated seabirds nest in mixed colonies, and this association may result ininterspecific interactions such as competition for common resources andkleptoparasitism. Trophic interactions were evaluated between the Kelp Gull (Larus dominicanus Lichtenstein, 1823) and Royal and Cayenne terns (Thalasseusmaximus maximus (Boddaert, 1783) and Thalasseussandvicensis eurygnathus (Saunders, 1876), respectively) nesting at amixed-species colony in an area with high availability of recreational fisherywaste for the opportunistic Kelp Gull. Diet analyses were based on gull chickstomach content samples and direct observations of food delivered to ternchicks in 2013 and 2014, complemented in 2014 with carbon and nitrogen stableisotope analysis of chick whole-blood samples. Main prey species of Kelp Gullchicks were Cynoscion guatucupa (Cuvier, 1830), a demersal species obtained fromrecreational fishery waste, Argentine anchovies (Engraulis anchoita Hubbs andMarini, 1935), and insects. Engraulis anchoita and Odontesthes spp. were themain prey of both tern species. Trophic niche and isotopic niche overlapbetween the Kelp Gull and Royal and Cayenne terns was low. Kelp Gullkleptoparasitism on Royal and Cayenne terns was ≤2.5% and <0.6%,respectively. The use of anthropogenic food subsidies by Kelp Gulls may bemediating the trophic relationships among species, favouring their use ofpredictable and abundant fishery waste over a more unpredictable pelagicschooling fish such as E. anchoita.