Search

I recorded information on pre-roost habitats of Western Marsh Harriers (Circus aeruginosus) near communal roost sites located in and around Keoladeo National Park (KNP), India, during three winters from 1997 to 2000. Harriers pre-roosted in different habitats in KNP compared to the surrounding areas (25-km radius). Harriers used trees as their main pre-roosting perches in KNP, but mainly used open fields in the surrounding areas. All nine tree species present near roost sites in KNP were used for pre-roosting. Among tree species used for pre-roosting, harriers preferred sacred fig (Ficus religiosa), a tall tree with a wide canopy. Babul (Vachellia nilotica) trees, though not preferred, were more utilized for pre-roosting, probably because of their abundance. The lack of suitable open areas near the primary roost site in KNP may help explain why harriers used trees as pre-roosting perches there. At other roost sites outside KNP where trees were sparse, harriers mainly pre-roosted on the ground. By perching on trees, harriers may be conspicuous to other arriving harriers, which likely helps the birds gather into a large roosting flock. Such large roosts may benefit harriers by providing protection from predators and a site where birds may obtain information on food resources. Although trees were used as pre-roosting sites at KNP, I did not observe any harriers roosting on trees overnight during the 3-yr study. [ABSTRACT FROM AUTHOR]

The Red Kite (Milvus milvus) is a common raptor in suitable areas of Austria, the Czech Republic, and Slovakia during the nonbreeding season. However, the exact number of birds wintering in these countries remains unknown. Through an integrated approach using satellite telemetry, direct field surveys at nocturnal roosts, and citizen science databases, we estimated the wintering population of Red Kites in this area during the winter of 2020/2021. Based on three surveys taking place at the beginning (28 November 2020), middle (9 January 2021), and end (5 February 2021) of winter, respectively, we counted 566, 558, and 536 Red Kites. The observations from online citizen science databases mostly appeared to correspond with the area of communal roost sites. Using our combined approach, the estimates of wintering Red Kites were determined as minimum numbers in the study area. A comparison of historical data (from the second half of the 20th and beginning of the 21st centuries, respectively) and our own results suggests that the wintering population of Red Kites in the study area has increased substantially. This dynamic could be caused by changes in climatic conditions, a shift of the birds' breeding range in Europe, changes in migration behavior and/or food availability, and/or conservation efforts. Milvus milvus es un rapaz común en áreas adecuadas de Austria, la República Checa y Eslovaquia durante la estación no reproductiva. Sin embargo, el número exacto de aves que pasan el invierno en estos países sigue siendo desconocido. A través de un enfoque integrado utilizando telemetría satelital, censos de campo directos en refugios nocturnos y bases de datos de ciencia ciudadana, estimamos la población invernante de M. milvus en esta área durante el invierno de 2020/2021. Basados en tres censos realizados al inicio (28 de noviembre de 2020), a la mitad (9 de enero de 2021) y al final (5 de febrero de 2021) del invierno, contamos 566, 558 y 536 individuos de M. milvus, respectivamente. Las observaciones de las bases de datos de ciencia ciudadana en línea parecieron corresponder principalmente con el área de los dormideros comunales. Usando nuestro enfoque combinado, las estimaciones de individuos invernantes de M. milvus se determinaron como números mínimos en el área de estudio. Una comparación de los datos históricos (de la segunda mitad del siglo XX y del inicio del siglo XXI, respectivamente) y nuestros propios resultados sugiere que la población invernante de M. milvus en el área de estudio ha aumentado sustancialmente. Esta dinámica podría estar causada por cambios en las condiciones climáticas, un cambio en el área de cría de las aves en Europa, cambios en el comportamiento migratorio y/o en la disponibilidad de alimentos, y/o los esfuerzos de conservación. [Traducción del equipo editorial] [ABSTRACT FROM AUTHOR]

The article presents the discussion on long-eared owls (Asio otus) frequently inhabiting human altered landscapes including residential areas in cities. Topics include pellet analyses usually documenting a very low proportion and occasional rather than regular occurrence of birds in the owls' diet; and owls wintering in cities usually hunting outside the settlements in grasslands, agricultural areas, or shrubby habitats.

Presentamos las tendencias y las características de un dormidero comunal pre-migratorio de Falco naumanni en la ciudad de Ioannina (Noroeste de Grecia), así como las zonas de campeo que usa la especie en este período. Durante los 15 años que duró el estudio, se registró un número máximo de 3500 individuos, concretamente en los años 2003 y 2004. Los dormideros se encuentran exclusivamente en ejemplares maduros de Platanus orientalis ubicados a orillas del lago Pamvotida, mientras que las zonas de campeo están en praderas alpinas a más de 34 km de los dormideros. En base al uso de un modelo de regresión logisitica binaria se puede predecir la presencia o ausencia de la especie en relación con la abundancia de ortópteros en la zona. Es vital la protección de los dormideros comunales y de las zonas de campeo durante la época de pre-migración para la conservación de la especie. [Traducción de Victoria Saravia editada] [ABSTRACT FROM AUTHOR]

The article presents a study on the White-tailed Kite's (Elanus leucurus) winter diet and communal roosting behavior in an agricultural habitat on the Argentine pampas from 2006-2008. Conducted during austral winters from May to July, the study observed an average of 11 kites gathered in a tall, dead and leafless Eucalyptus viminalis before roosting in to more densely foliated trees. Their diet consisted of small mammals, mainly Calomys sp. and Akodon azarae. Further studies are suggested to improve knowledge on their feeding behavior during winter.

The article focuses on a study conducted by authors on gregarious roosting and early morning perching behavior of American Kestrels. Topics discussed include roosting behavior seen in many species of raptors which may benefit individuals in thermoregulation, foraging efficiency and protection from predators, detection of communal roost sites for management and conservation, roosting if falcons together during migration and perching behavior common in kestrels during migration and late summer.