INVESTIGADORES
CASAUX Ricardo Jorge
artículos
Título:
The unexpected diet of breeding Imperial Shags (Phalacrocorax atriceps) at the Nahuel Huapi Lake, Patagonia: implications on population trends?
Autor/es:
CASAUX R,; BERTOLIN M.; TARTARA A.
Revista:
ORNITOLOGIA NEOTROPICAL
Editorial:
NEOTROPICAL ORNITHOLOGICAL SOC
Referencias:
Lugar: ALEMANIA; Año: 2010 vol. 21 p. 457 - 462
ISSN:
1075-4377
Resumen:
INTRODUCTION
The Imperial Shag Phalacrocorax
atriceps is well distributed in the coast of South
America and in Malvinas/Falkland Islands (Orta 1992). This shag is
marine in most its range and forage predominantly on fish, although
invertebrates were frequently reported as present in the diet (e.g., Punta et al. 2003, Ferrari et al. 2004, Bulgarella et al. 2008).
Reynolds
(1934) reported the presence of the Imperial Shag breeding at Yehuin Lake, Tierra
del Fuego, and latter on Pereyra (1945, quoted in Navas 1970), Chebez &
Gómez (1988) and Rasmussen et al.
(1992) reported the existence of the only other three populations of this shag
breeding in freshwater environments, the Nahuel Huapi (NHL), Fagnano, and
Vintter lakes respectively. Despite the potential interest in studying these
populations, few studies provided information on the biology of these shags. Although
not globally threatened, the Imperial shag at the NHL is locally endangered and
between the summers of 1990 (Rasmussen et
al. 1993) and 2005 (Pastore et al.
2005) the total number of individuals decreased in a 68%.
Thus, the aim
of this study is provide the first information on the diet of the Imperial Shag
breeding at the NHL to improve the knowledge of the foraging behavior of this
species as well as to explore the linkage between diet composition and the
reported declining trend of this population