Ornitología Neotropical (E-Journal)
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A MIGRATORY BOTTLENECK FOR THE WHITE-THROATED HAWK BUTEO ALBIGULA IN THE ANDEAN FOOTHILLS OF CENTRAL CHILE
No full textThe White-throated Hawk Buteo albigula is one of the most abundant migratory raptors in the Austral-Neotropical system, but no bottlenecks in its migratory routes are known. Here, we describe the finding of the first migratory bottleneck for this species on the Andean slopes of central Chile. We counted a total of 5,424 White-throated Hawks migrating from south to north from 17 March until 13 April 2023, in Cachapoal, O'Higgins Region, Chile (34° S; 70° W). In addition, we counted 1,314 Variable Hawks Geranoaetus polyosoma and seven Cinereous Harriers Circus cinereus migrating through this site for a total of 6,745 raptors, which represent the largest count of migrant raptors in the Austral-Neotropical system. Both, the passage rate (24.2 hawks/hour) and the total number of White-throated Hawks observed per season, were higher at Cachapoal than at any other previous count site (daily passage rate range = 1.0–7.2 hawks/hour; total hawks per season = 35–294). We estimated that over 84% of the breeding population of White-throated Hawks transit the Cachapoal bottleneck during their autumn migration. Remote tracking technologies and observations at other points of the Andes should help to further examine this proposal. Continuing with the long-term count of White-throated Hawks in this bottleneck will allow us to assess the population trends of this important predator in the southern temperate forests
COLONIZACIÓN, PATRONES DE DISTRIBUCIÓN Y USO DE HÁBITAT DEL IBIS NEGRO PHIMOSUS INFUSCATUS EN LA ZONA URBANA DEL VALLE DE ABURRÁ, COLOMBIA
Get PDFEn aves ha sido ampliamente estudiado el cambio de distribuciones causado por actividades humanas. La urbanización, una de las principales modificaciones del paisaje, puede tener efectos ecológicos adversos, pero también puede ofrecer recursos y favorecer el establecimiento de poblaciones. Este proceso se denomina colonización y ha sido poco estudiado en el Neotrópico. Phimosus infuscatus una especie que recientemente ha aumentado sus avistamientos, en ciudades fuera de su ámbito de distribución, es un gran candidato para estudiar este proceso en el Valle de Aburrá, Colombia. Para lograr eso, buscamos y filtramos todos los registros de presencia histórica, en bibliografía y portales de ciencia ciudadana, para graficar anualmente su aparición. Realizamos observaciones de campo y obtuvimos registros georreferenciados, para caracterizar su uso de hábitat y comportamiento. Por medio de imágenes satelitales clasificamos el territorio y graficamos los registros, para analizar las áreas usadas por la especie. Hallamos 1279 registros en total y filtramos 487, los primeros registros ocurren en los años 2008 y 2010, seguido de un rápido patrón de expansión en 10 años. Observamos individuos y grupos en actividades, principalmente de forrajeo y percha. Las áreas más usadas por la especie son zonas verdes y fuentes hídricas en el territorio urbano. La especie demuestra un patrón dinámico de expansión, y ha hallado las condiciones adecuadas para su establecimiento. Hay que considerar los sesgos inherentes a registros de ciencia ciudadana y de carencia de inventarios históricos locales. Casos de establecimiento urbano también se han dado en otras ciudades de Colombia y en Suramérica, así como en otros continentes con diferentes representantes de la familia Threskiornitidae. Finalmente, la especie parece mostrar tolerancia a las perturbaciones humanas, y es posible que el uso de hábitat se vea afectado por la estacionalidad local. Sugerimos iniciar un monitoreo continuo y estudiar otros aspectos ecológicos
BREEDING BIOLOGY OF THE LOGGERHEAD SHRIKE LANIUS LUDOVICIANUS IN CENTRAL MEXICO
Get PDFThe Loggerhead Shrike Lanius ludovicianus has an exceptionally broad distribution in North America, with the southernmost populations found in central Mexico. The species has experienced severe declines throughout its range, and thus, is of conservation concern, particularly in USA and Canada. Life history data is scarce for Mexico, where both resident and migratory populations are found. In this study we provide information on the breeding biology of a population of Loggerhead Shrikes near the southern limit of its distribution in central Mexico. Based on data from 70 nests over three breeding seasons (2007–2009), we estimated the average nest density as 0.85 nests/ha with most nests built in mesquite trees Prosopis laevigata. Average clutch initiation date was March 28, with variation among years. The breeding period averaged 3.5 months, starting at the end of February, and extending to early June. The laying period averaged 4.6 days, incubation averaged 18 days, and the average brooding period 16.6 days, for a total average of 39.2 days from egg laying to the end of brooding. Clutch size averaged 4.1 eggs (range 2–5) with a mode of four eggs. The nesting success for the three years combined was 64.3% (range 54.5–68.9%). Daily survival rate was estimated to be 0.749 using logistic exposure. The average number of fledglings at successful nests was 1.5. Predation was the main cause of nest failure, accounting for 35.7% of all active nests. In general, life history traits of this Mexican Loggerhead Shrike population are like those reported for breeding populations in more northern parts of its range; however, clutch size was smaller and average incubation period was significantly longer, probably because of latitudinally-related environmental factors
NECTAR ROBBING BY THE RED-TAILED COMET SAPPHO SPARGANURUS: THE VALUE OF CITIZEN SCIENCE TO DOCUMENT INFREQUENT BEHAVIOR IN BIRDS
Get PDFNectar robbing by hummingbirds, the extraction of nectar using perforations instead of the corolla, is seldom documented in the literature. Here, we present the first photographic record of nectar robbing by the Red-tailed Comet Sappho sparganurus in Bolivia and examine published and photographic evidence of this behavior. We found no published evidence of nectar robbing by Red-tailed Comets in peer-reviewed literature. However, we found that about 4% of the photographs of hummingbird-flower interactions involving this species on citizen science platforms showed clear nectar robbing behavior. Our results suggest that nectar robbing is not an uncommon behavior for the Red-tailed Comet and highlight the hidden, yet immense, value of citizen science photographic databases to document avian natural history and behavior
HIGH FREQUENCY OF BATS IN THE DIET OF THE BARN OWL TYTO ALBA IN A LOWLAND DRY FOREST IN TOLIMA, COLOMBIA
Get PDFThe cosmopolitan distribution of the Barn Owl Tyto alba and its relatively well documented diet through the study of pellets have provided evidence of the broad diversity of prey it relies on. In most studies, both in tropical and temperate regions, rodents are its main prey, with other small mammals and vertebrates, and insects complementing its diet. Although bats have been recorded in the diet of T. alba at many localities, they seldom represent an important part of its diet. This study describes the diet of a small colony of T. alba from a mosaic of agricultural fields, pastures for cattle ranching and tropical dry forests in Tolima, central Colombia. Overall, we collected 516 pellets between 2016 and 2017 in a non-systematic manner, and recovered 335 skulls of rodents (67%), bats (29%), birds (3%) and shrews (1%), as well as invertebrate prey. The large proportion of bats in the diet of T. alba in this study is only matched by a few other studies, and further documents the wide range of prey included in the diet of this nocturnal raptor. This is one of the first studies on the diet of T. alba in tropical dry forests in Colombia and complements the existing data on its diet in the American tropics and worldwide
PRESENTATION OF SPECIAL VOLUME: THE XITH NEOTROPICAL ORNITHOLOGICAL CONGRESS, SAN JOSÉ, COSTA RICA, JULY 28TH TO AUGUST 1ST 2019
Get PDFACTIVE ANTING BEHAVIOR IN RED-CRESTED CARDINAL PAROARIA CORONATA AND RUFOUS-COLLARED SPARROW ZONOTRICHIA CAPENSIS
Get PDFOver 200 bird species exhibit a behavior known as anting, wherein birds spread ants or other arthropods, along with their secretions, to their plumage. Anting is hypothesized to serve purposes such as controlling skin bacteria or fungi, repelling ectoparasites, alleviating skin irritation during molting, or pre-treating ants prior to ingestion. In this note, I present the first records of anting behavior in an adult Red-crested Cardinal Paroaria coronata, and in an adult and a juvenile Rufous-collared Sparrow Zonotrichia capensis. These birds rubbed ants of Camponotus mus (Formicidae: Formicinae) on their feathers. The cardinal rubbed the ants on the remiges of both wings, similar to the juvenile sparrow, while the adult sparrow applied them on its fairly deteriorated rectrices. In none of the cases were the ants consumed. These observations suggest that, at least in adult sparrows, the application of ants responded to the presence of ectoparasites
DESCRIPCIÓN DEL NIDO Y BIOLOGÍA DEL ANIDAMIENTO DEL TIJERAL LEONADO SYLVIORTHORHYNCHUS YANACENSIS EN BOSQUES DE POLYLEPIS BESSERI
Get PDFSylviorthorhynchus yanacensis es un residente especialista restringido a bosques de Polylepis de los Andes de Perú, Bolivia y Argentina. Aunque son necesarios los datos sobre su reproducción, aún hay escasos reportes sobre las características del nido y la biología del anidamiento. En el presente estudio, en un periodo de cuatro años (2002–2005) se registraron 54 nidos construidos sobre P. besseri en la Cordillera de Cochabamba, Bolivia. El nido se construye en cinco fases en forma de domo, con cuatro capas donde el material principal de las primeras tres capas son gramíneas altoandinas. El tamaño promedio de la puesta fue de 1,8 huevos, con un periodo de incubación de 21 a 24 días. Los polluelos permanecieron 21 días en el nido, con un cuidado parental que se extendió hasta ocho meses después que abandonaron el nido. El éxito de los nidos fue de 59%. El periodo reproductivo, tiempo de construcción del nido, anidamiento prolongado y la arquitectura del nido parecen estar influenciados por la época de lluvia y su frecuente descenso de la temperatura
HÁBITOS ALIMENTARIOS DEL LECHUZÓN OREJUDO ASIO CLAMATOR EN UNA ZONA URBANA DEL SUR DE BRASIL
Get PDFEl lechuzón orejudo Asio clamator es una especie ampliamente distribuida en la región neotropical. Su rango geográfico abarca desde el norte de México hasta el centro de Argentina. En este trabajo presentamos datos sobre la dieta del A. clamator en la ciudad de Pelotas en Rio Grande do Sul, Brasil, registrados en la primavera austral durante el periodo post-reproductivo de la especie. Se recolectaron 39 egagrópilas, a partir de las cuales fueron identificadas un total de 46 presas, pertenecientes a ocho taxa. Los grupos más importantes en la dieta fueron los mamíferos, que representaron 73,9 % de los ítems de la dieta, y las aves, que representaron 10,85 % de los ítems consumidos. En nuestro estudio una especie exótica, Rattus norvegicus, fue la principal presa consumida