BoletÍn Chileno de Ornitología Volumen 17 Número 2 – 2011

Artículos

INFLUENCIA DEL TAMAÑO DE LA BANDADA SOBRE EL COMPORTAMIENTO DE ALIMENTACIÓN Y VIGILANCIA EN BANDURRIA (Theristicus melanopis, Gmelin 1789)
ALBERTO GANTZ, ROBERTO SCHLATTER & MIGUEL YAÑEZ.

pp. 92-102 | PDF (72 K)

Resumen

Flock size influence on feeding and vigilance behavior of Black-faced Ibis (Theristicus melanopis, Gmelin 1789)
ALBERTO GANTZ, ROBERTO SCHLATTER & MIGUEL YAÑEZ

A. Gantz, agantz@ulagos.cl

Entre septiembre y diciembre de 1989 analizamos el efecto del tamaño de la bandada sobre las tasas de alimentación y vigilancia de la bandurria (Theristicus melanopis). La bandurria formó bandadas de tamaños pequeños durante el período de estudio. Bandadas de 5 a 6 integrantes representaron la mayor proporción de tamaños del total de observaciones. Nuestros resultados señalaron que las variables de alimentación y vigilancia en la bandurria son independientes del tamaño de la bandada. Sólo la tasa de picoteos y la tasa de vigilancia mostraron una correlación positiva significativa con el tamaño de la bandada. Sin embargo, la varianza explicada por el tamaño de la bandada fue mínima para todas las variables analizadas. Concluimos que la bandurria probablemente ha desarrollado sistemas eficientes de vigilancia, que le aportan a las bandadas pequeñas una mayor protección contra los depredadores y eventualmente les permitiría adquirir mayores beneficios tróficos.



Contribuciones breves

DIETA DEL PATO QUETRU NO VOLADOR (Tachyeres pteneres) EN ISLA GUAPIQUILÁN, CHILOÉ, SUR DE CHILE
CLAUDIO TOBAR, ALDO ARRIAGADA, JAIME RAU, JAIME CURSACH, CRISTIÁN SUAZO & RODRIGO MÁRQUEZ.

pp. 103-108 | PDF (67K)

Resumen

Diet of Flightless Steamer-Duck (Tachyeres pteneres) at Guapiquilán Island, Chiloé, southern Chile
CLAUDIO TOBAR, ALDO ARRIAGADA, JAIME RAU, JAIME CURSACH, CRISTIÁN SUAZO & RODRIGO MÁRQUEZ.

C. Tobar, claudiobiomar@gmail.com

The diet of the Flightless Steamer-duck (Tachyeres pteneres) was determined quantitatively during the summer 2009 at the E coast of Guapiquilán Island (43°23’S; 74°14’W), Chiloé, southern Chile on the basis of 24 feces. A total of 38 hard remains were identified from marine invertebrates of six families (Mytilidae, Fissurellidae, Patellidae, Chitonidae, Cancridae, Majidae) and to a minor extent from marine vertebrates (unidentified fish). The diet was represented mainly by crustaceans (Cancridae: 60.5%) and mollusks (Patellidae: 13.2%), whereas a smaller percentage (7.9%) was made of unidentified fishes. These findings suggest that Tachyeres pteneres preys especially on juvenile crustaceans and benthic mollusks.

PRESENCIA DE CHURRÍN DEL NORTE (Scytalopus fuscus) EN LA CORDILLERA DE NAHUELBUTA, REGION DE LA ARAUCANÍA, CHILE
HERALDO V. NORAMBUENA, RODRIGO BARROS & VÍCTOR RAIMILLA.

pp. 109-112 | PDF (114 K)

Resumen

Presence of Dusky Tapaculo (Scytalopus fuscus) in the Cordillera of Nahuelbuta, Araucania region, Chile
HERALDO V. NORAMBUENA, RODRIGO BARROS & VÍCTOR RAIMILLA.

H.V. Norambuena, buteonis@gmail.com

The endemic Dusky Tapaculo (Scytalopus fuscus) normally ranges from 29º throughout 36º S in Chile. In the present note we report on 14 independent sightings of Dusky Tapaculos at localities around the Cordillera of Nahuelbuta (37-38º S) in the Araucania region, southern Chile. All individuals were identified by their calls, both spontaneous (N=10) and induced by play-back (N=4) and were observed on hill slopes and densely vegetated gullies. At the sites we also observed other tapaculo species including Magellanic (S. magellanicus) and Ochre-flanked (Eugralla paradoxa). This report extends the previous known specie‘s distribution in ca. 190 km south.

ABERRACIONES CROMÁTICAS DEL PLUMAJE EN AVES: NUEVOS REPORTES EN CHILE
DANNY FUENTES & DANIEL GONZÁLEZ-ACUÑA

pp.113-121 | PDF (299K)

Resumen

Chromatic aberrations in bird feathers: new reports for Chile
DANNY FUENTES & DANIEL GONZÁLEZ-ACUÑA

D. González-Acuña, danigonz@udec.cl

In Chile, reports on chromatic aberrations in feathers of wild birds are scarce. Such aberrations are produced by alterations in the concentration of melanin, producing albinism, leucism, dilution, schizochroism and melanism. In this note we present graphic evidence on chromatic aberrations in feathers of several wild birds including House Sparrow, Grey-hooded Sierra-finch, Austral Thrush, Long-tailed Meadowlark, Burrowing Owl, Neotropic Cormorant, Rufous-collared Sparrow, Magellanic and Gentoo Penguins.