Ornitología Neotropical (E-Journal)
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USO DE HÁBITAT Y COMPORTAMIENTO DEL RASCÓN ANDINO (RALLUS SEMIPLUMBEUS) EN EL HUMEDAL LA CONEJERA, COLOMBIA
No full textEl rascón andino (Rallus semiplumbeus) es un ave endémica a la cordillera oriental de Colombia, considerada en peligro de extin- ción (EN). Poco se conoce sobre sus requerimientos ecológicos y su uso del espacio en los humedales de la sabana de Bogotá. Describimos el uso del hábitat y patrones temporales de actividad vocal, basados en un monitoreo entre febrero y noviembre de 2011, en el humedal La Conejera, Bogotá, Colombia. Los datos indicaron un frecuente uso de vegetación juncoide, como ha sido reportado anteriormente. La activi- dad vocal y el uso de juncales se intensificó durante la temporada reproductiva, lo que sugiere que la especie tiene una alta especificidad hacia este hábitat. Estudios que cuantifiquen el uso respecto a la disponibilidad de hábitat serán importantes para corroborar esta aparente preferencia
OBSERVATIONS ON THE PARENTAL CARE BEHAVIOR OF THE MAROON-CHESTED GROUND DOVE (PARACLARAVIS MONDETOURA) IN SOUTHEASTERN ECUADOR
Get PDFWe present the first observations of parental care behaviors of the Maroon-chested Ground-Dove (Claravis mondetoura) using 222.5 hours of recorded observations from a single nest found in tropical montane forest in the Tapichalaca Biological Reserve in south-east Ecuador. Recording began with the onset of incubation and continued through fledging. Observations of male and female attendance at the nest were used to analyze visit frequency and timing, duration, and differences in male and female investment in the reproductive effort. Both adults spent time incubating, brooding, and shared feeding responsibilities and patterns observed reflected those commonly seen in other Neotropical Columbidae
PREDATORY BEHAVIOR OF A RUFOUS-CAPPED MOTMOT (BARYPHTHENGUS RUFICAPILLUS) ON A MAMMAL (MONODELPHIS SP.)
Get PDFWhile motmots (Momotidae) are known to feed on mammals, this information comes mainly from the analysis of stomach con- tents. On 2 November 2018, our camera trap, located in the Projeto Dacnis area in São Francisco Xavier, a district of the municipality of São José dos Campos, State of São Paulo, Brazil, recorded a Rufous-capped Motmot (Baryphthengus ruficapillus) on a perch with a small opossum (Monodelphis sp.) in its bill. Since the bird repeatedly hit the mammal ́s head against the perch, we assumed it was a predation event. This is the first video record of a B. ruficapillus preying on a mammal, as well as the first record of a motmot preying on a marsupial. Videos record- ed by camera traps are a valuable source of natural history data, as they provide records not only about dietary items, but also about the associated predatory behavior
AVIFAUNA DE CUATRO PLANTACIONES DE HIGO (FICUS CARICA) EN EL CENTRO-ESTE DE ARGENTINA
Get PDFEn el presente estudio se evaluó la composición de la avifauna y el daño causado por aves a los frutos de cultivos de higo comesti- ble (Ficus carica) en la provincia de Santa Fe, Argentina. Se calculó la riqueza y abundancia de aves y la intensidad del daño por parte de las mismas en cuatro plantaciones de higo, entre diciembre de 2014 y mayo de 2015. A partir de la relación con el cultivo, se clasificó a las espe- cies de aves en tres categorías: potencialmente perjudiciales, benéficas o neutras. No se registraron diferencias en la riqueza de especies entre los grupos, pero se registraron diferencias en la abundancia entre febrero y mayo de 2015. La intensidad del daño fue baja a lo largo del estudio y no parece estar relacionada con la abundancia o riqueza de aves potencialmente perjudiciales. Si bien el alcance de este estu- dio es restringido, por tratarse de cuatro plantaciones y una sola temporada, los resultados sugieren que el daño por aves en plantaciones de higo sería poco relevante
AN UPDATE ON THE BREEDING BIOLOGY AND BIOMETRY OF HAUXWELL’S THRUSH (TURDUS HAUXWELLI) FROM LOWLAND SOUTHWESTERN BRAZILIAN AMAZON
Get PDFThe Neotropical region is home to a large number of species of the genus Turdus. While the breeding biology of this genus is well known in general, data are scant for some Amazonian species, including Hauxwell’s Thrush (Turdus hauxwelli). Here, we present new data on the breeding and biometry of T. hauxwelli based on field observations and captures in a fragment of terra firme forest in southwestern Amazonia, Brazil. We monitored six active nests between 2012 and 2014, and collected data on the incubation and nestling phases on five nests. The nests were built at a mean height of 1.9 m (range: 0.53–3.2 m) above the ground. We estimated incubation time as 13–14 days. We monitored the development of 11 nestlings in four nests. The mean weight of the newly-hatched nestlings was 6.56 g (range: 4.3–9.0 g [SD = 2.27]). The constant (K) of the growth rate in the nestlings was 0.43 (range: 0.31–0.51; SE=0.03), with an asymptote of 51.1 g (range: 45.04 - 62.32; SE= 0.31). The daily survival rate of the nests during the incubation phase was 97%. However, the survival rate during the nestling phase was only 12%. Mayfield’s success was 70% during the incubation phase and 21% during the development of the nestlings, whereas apparent success was 75% in the incubation phase and 27% in the nestling phase. We banded and measured 64 adult individuals, 13 juveniles, and four nestlings in 2005 and between 2009 and 2017. Minimum longevity, calculated from the recapture of banded individuals, was 6 years, 3 months and 11 days (or 2298 days after banding). Our results indicate that T. hauxwelli has a breeding season restricted to a few months of the rainy season (November–March), which overlaps with molt
A RECORD OF “DILUTION” PLUMAGE ABERRATION IN THE RUFESCENT TIGER-HERON (TIGRISOMA LINEATUM)
Get PDFPlumage aberrations are common in wild birds; however, there are few documented records for most Neotropical bird species. Here, we present the first documented record of dilution plumage aberration in Rufescent Tiger-Heron (Tigrisoma lineatum). In August 2017, we observed an individual of Rufescent Tiger-Heron with a “diluted” plumage coloration compared to the typical coloration for this species. With yellowish-brown feathers in head and neck, and especially a pale gray coloration in upperparts, the overall appearance seems to be, most likely, a case of “Pastel” dilution aberration. However, the pale gray tones may have been caused by the light conditions during obser- vation which make it difficult to determine the dilution type with certainty. The documentation of these cases can be a valuable source of information to understand chromatic aberrations and variations between different groups of birds
PUNTOS CALIENTES Y FACTORES ASOCIADOS AL ATROPELLO DE AVES RAPACES EN UNA RUTA COSTERA DE LA ZONA SEMIÁRIDA DE CHILE CENTRAL
Get PDFThe pressures of road infrastructure on wildlife are among the eleven main threats to biodiversity conservation. Birds are one of the most threatened groups, mainly through direct collisions with road traffic and the fragmentation of their habitats. We characterized the assem- blage of raptors that were impacted on a coastal highway in central Chile and analyzed the possible relationship between areas with high impact density and some landscape variables. Between April 2016 and June 2017 we registered 86 raptor carcasses, nine species belonging to five different families, among which Tyto alba, Milvago chimango, and Bubo virginianus were the birds with a higher frequency of road- kills. These impacts were concentrated between February and April 2017. In the sections studied, we detected eight hot spots that included 37% of the impacts and found at least five variables related to these road kill hot spots: i) A larger surface covered with trees, ii) a small number of lighting poles, iii) sites closer to creeks, iv) road sections without curves, and v) double tracks would favor roadkills for these birds in the studied site. Additionally, collisions for the different species of raptors recorded in this study could be due to the availability of prey on the edges of the road, their foraging strategies, and the ecology of these birds, especially during breeding season
EXPERIMENTAL EVIDENCE OF ALARM EAVESDROPPING ON AMAZONIAN MIXED-FLOCK FOLLOWERS BY TWO SOCIAL SENTINEL SPECIES: THE DUSKY-THROATED ANTSHRIKE THAMNOMANES ARDESIACUS AND THE CINEREOUS ANTSHRIKE T. SCHISTOGYNUS
Get PDFMixed-species flocks of bird represent an ecological phenomena resulting from a diversity of complex interactions and evolutionary pressures. Paleotropical, Neotropical and temperate forests include many examples of passerine bird who interact by forming mixed-species flocks and by eavesdropping on the alarm calls produced by heterospecifics. In the mixed-flock systems of Amazonia, species of antshrike (Thamnomanes sp.) have been shown to provide other flock members valuable information regarding threats from predation through their frequent alarm calls. Several species of flock attendees respond to the alarms of antshrikes with predator-avoidance behaviors, but no study has yet shown a reciprocal relationship between flock members and flock-leading antshrikes. Apparently distinct from mixed-flock systems of other forests, there has been little evidence to support that flock-leading species of antshrike benefit from the alarm signals of other flock members. Using alarm signals recorded during in situ exposures of mixed-flock species to trained raptors, we conducted a playback experiment to 16 different mixed flocks to see to what degree antshrikes may be eavesdropping on the alarms of Myrmotherula antwrens. 8 Dusky-throated Antshrike Thamnomanes ardesiacus and 8 Cinereous Antshrike T. schistogynus were presented with i) conspecific alarms ii) White-flanked Antwren Myrmotherula axillaris alarms iii) Grey Antwren M. menetriesii alarms and iv) a control. The results of our experiment support that the alarms of the two species of antwren illicit a significant response from both species of antshrike. Our model also shows the responses of antshrikes to antwren alarms are indistinguishable from their response to conspecific alarms, yet different from a control (Marginal R2=.36, Conditional R2=.37). This suggests that highly social flock-leading species such as Thamnomanes antshrikes may benefit from the information provided by flock mates regarding predators. Further, these patterns are consistent with eavesdropping interactions observed within mixed-flocks in ecologically similar but geographically distant forests
DIVERSITY AND SEASONALITY OF BIRDS IN PERMANENT WATERHOLES IN THE PERUVIAN NORTHWEST
No full textIn arid environments, the presence of water sources is key for biological communities as they provide a vital element that is scarce. In this study, we evaluated the diversity and the relative abundance of bird species in seven permanent waterholes, located along an elevational gradient in mountain dry forests in northwestern Peru. From January to December 2016, we analyzed 114,438 photos (22,888 photo events) obtained through camera traps, and counted bird species and individuals photographed at these waterholes. We measured how bird diversity and abundance varied between waterholes during the humid (January to May) and dry (June to December) seasons. In total, we made 4,137 detections of 35 bird species. Among these, 10 species were endemic to the Tumbesian area, including one that is glob- ally endangered (the White-Winged Guan, Penelope albipennis). 95% of detections in all waterholes corresponded to four species of pigeons/ doves (Columbidae). We also recorded two migratory species, including one that is uncommon in northwestern Peru (the Slaty Thrush, Tur- dus nigriceps). The number of bird detections during the dry season was almost two times higher than that during the humid season. We did not find any correlations between relative abundance/diversity at waterholes and elevation or distance to agricultural areas. We postulate that permanent waterholes are a key to bird species in the northwestern Peruvian dry forests and should be protected, since they provide a scarce resource to several range-restricted species, including one that is globally threatened