The relationship between the feather tuft of the uropygial gland and terrestrial/aquatic birds

The bird´s uropygial gland has a papilla in its caudal end and it can also show a feather tuft. These feathers may have a raquis or not. The purpose of our study was to compare the number, dimensions and types of the tuft´s feathers in aquatic and terrestrial birds, as well as to investigate whether the potential differences are related or determined by their dissimilar habitats. The uropygial glands were removed and the tuft´s feathers were extracted and then measured, prepared for magnifying glass observation and photo shoot. Aquatic birds were found to have not only a larger number of feathers in the tuft but also longer feathers than terrestrial birds. However, the length ratio between calamus/raquis was higher in terrestrial birds. Almost all the species under study presented the same type of feathers except for the three penguin species that showed a peculiar type. The differences found between the tuft´s feathers of the studied species are related with the environment. Aquatic birds have a longer length of the feather tuft because they may produce a greater amount of secretion than terrestrial birds.Fil: Chiale, Maria Cecilia. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Zoología de Vertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Montalti, Diego. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Zoología de Vertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Criterios para determinar la edad de pollos de Flamenco Austral (Phoenicopterus chilensis) en cautiverio basadas en características del plumaje

Many aspects of the breeding biology of the Chilean Flamingo (Phoenicopterus chilensis) are still unknown. We studied captive breeding Chilean Flamingos at La Plata Zoo, Buenos Aires, Argentina between February and July 2014 to document chick‐aging methods based on molt and coloration of bare parts, such as beak and legs. The development of young was divided in three age categories: 1. Chick (less than 15 days old), with white down and salmonpink beak and red coral legs. 2. Pre‐juvenile (1?3 months old), birds covered with gray down (due to a combination of a double down coat) and when the white down falls, a brownish down coat is more evident. In this stage, the beak had darkened and the legs turned dark gray. 3. The last category is the juvenile (4?5 months old), characterized by the presence of vaned feathers, dorsal feathers are pale brown with a dark raquis, underparts are white and inner coverts have a pale‐salmon coloration; the beak is curved and has a blueish base with a charcoal gray tip and legs are pale gray. The information presented in this study may help to age young Chilean Flamingos in the wild.Fil: Chiale, Maria Cecilia. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Departamento de Ciencias Básicas. Cátedra de Histología y Embriología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Montalti, Diego. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Zoología de Vertebrados. Sección Ornitología; ArgentinaFil: Maragliano, María Graciela. Instituto de Formación Docente y Técnica N° 35; Argentin

Hematology, Biochemistry and Serum Protein Analyses of Antarctic and non-Antarctic Skuas

Determination of hematological and biochemical parameters provides important data to assess the physiological condition in wild birds. Therefore, to carry out ecophysiology or conservation studies it is essential to establish baseline physiological parameters and how these change with age and life history events. Hematological (hematocrit, hemoglobin and erythrocyte sedimentation) and biochemical (glucose, total lipids and proteins, aspartate and alanine aminotransferase activities and electrolyte concentration) reference values were determined in two Antarctic migratory bird species, the Brown Skua (Stercorarius antarcticus) and South Polar Skua (S. maccormicki), from South Shetland Island during breeding season. Also, hematological data (hematocrit) were determined for non-Antarctic skuas, with Chilean (S. chilensis) and Falkland (S. antarcticus antarcticus) skuas sampled in the Beagle Channel islands (Tierra del Fuego Province) and Viana Island (Chubut Province), Argentina, respectively. Differences between adult Antarctic skua species were observed in hemoglobin, erythrocyte sedimentation, total lipids and aspartate aminotransferase activity. In addition, age-related differences in Antarctic skuas in hematocrit, hemoglobin, glucose and total protein values were observed. Serum reference protein fractions (Albumin, α1, α2, and globulins) were assessed by electrophoresis for Antarctic and non-Antarctic skuas. Similar protein patterns were observed between South Polar and Chilean skuas as well between Falkland Skua and Brown Skua. The differences between adult sympatric Antarctic skuas may be related to their nutritional status and species-specific migrations, feeding habits and the differential use of the breeding niches, while the age variation may be related to physiological development processes in chicks or to the energy expenditure in adults during breeding.Fil: Ibañez, Andres Esteban. Universidad Nacional de la Plata. Facultad de Ciencias Naturales y Museo. División Zoología de Vertebrados. Sección Ornitología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Najle, Roberto. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Veterinarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Larsen, Karen Elizabeth. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Veterinarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Centro de Investigación Veterinaria de Tandil. Universidad Nacional del Centro de la Provincia de Buenos Aires. Centro de Investigación Veterinaria de Tandil. Provincia de Buenos Aires. Gobernación. Comision de Investigaciones Científicas. Centro de Investigación Veterinaria de Tandil; ArgentinaFil: Montalti, Diego. Universidad Nacional de la Plata. Facultad de Ciencias Naturales y Museo. Departamento Científico Zoología Vertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Lichens in the nests of European starling Sturnus vulgaris serve a mate attraction rather than insecticidal function

The European starling Sturnus vulgaris is a hole-nesting bird in which the male builds a voluminous nest using a wide variety of materials such as twigs, grass, leaves, feathers, and lichens. The function of lichens in starling nests has not been assessed until now and we hypothesize that this material is related to a mate attraction function or is used to protect nestlings from parasites due to the presence of secondary compounds with insecticidal effects with the lichens. We aimed to identify the lichen species and frequency of lichen use in European starling nests, and to determine if the presence of this material is correlated with mate attraction or with an insecticidal function. We found lichens in 45% of nests, mainly represented by Ramalina celastri. The lichens were added to the nests mainly before the beginning and at the end of nest building and egg-laying started earlier in nests with lichens than those without lichens. No association was found between the presence of lichen and the intensity of Philornis larvae (Diptera), a parasite that infests starling nestlings. Our results suggest that the addition of lichens could be related to mate attraction and a stimulus for the beginning of egg-laying but did not have an antiparasitic function in European starling nests.Fil: Ibañez, Lucía Mariel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Departamento Científico Zoología Vertebrados; ArgentinaFil: García, Renato Andrés. Laboratorio de Entrenamiento Multidisciplinario para la Investigación Tecnológica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Fiorini, Vanina Dafne. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; ArgentinaFil: Montalti, Diego. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Departamento Científico Zoología Vertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

The single surgeon learning curve of laparoscopic liver resection : a continuous evolving process through stepwise difficulties

The aim of the study was to evaluate the single-surgeon learning curve (SSLC) in laparoscopic liver surgery over an 11-year period with risk-adjusted (RA) cumulative sum control chart analysis.Laparoscopic liver resection (LLR) is a challenging and highly demanding procedure. No specific data are available for defining the feasibility and reproducibility of the SSLC regarding a consistent and consecutive caseload volume over a specified time period.A total of 319 LLR performed by a single surgeon between June 2003 and May 2014 were retrospectively analyzed. A difficulty scale (DS) ranging from 1 to 10 was created to rate the technical difficulty of each LLR. The risk-adjusted cumulative sum control chart (RA-CUSUM) analysis evaluated conversion rate (CR), operative time (OT) and blood loss (BL). Perioperative morbidity and mortality were also analyzed.The RA-CUSUM analysis of the DS identified 3 different periods: P1 (n = 91 cases), with a mean DS of 3.8; P2 (cases 92-159), with a mean DS of 5.3; and P3 (cases 160-319), with a mean DS of 4.7. P2 presented the highest conversion and morbidity rates with a longer OT, whereas P3 showed the best results (P<0.001). Fifty cases were needed to achieve a significant decrease in BL. The overall morbidity rate was 13.8%; no perioperative mortality was observed.According to our analysis, at least 160 cases (P3) are needed to complete the SSLC performing safely different types of LLR. A minimum of 50 cases can provide a significant decrease in BL. Based on these findings, a longer learning curve should be anticipated to broaden the indications for LLR

Unveiling the influence of task-relevance of emotional faces on behavioral reactions in a multi-face context using a novel Flanker-Go/No-go task

Recent research indicates that emotional faces affect motor control only when task-relevant. However, these studies utilized a single-face presentation, which does not accurately mirror real-life situations wherein we frequently engage with multiple individuals simultaneously. To overcome this limitation, we gave 40 participants two versions of a novel Flanker-Go/No-go task, where we presented three-face stimuli with a central target and two task-irrelevant flankers that could be congruent or incongruent with the target for valence and gender. In the Emotional Discrimination Task (EDT), participants had to respond to fearful or happy targets and refrain from moving with neutral ones. In the Gender Discrimination Task (GDT), the same images were shown, but participants had to respond according to the target's gender. In line with previous studies, we found an effect of valence only in EDT, where fearful targets increased reaction times and omission error rates compared to happy faces. Notably, the flanker effect, i.e., slower and less accurate responses in incongruent than congruent conditions, was not found. This likely stems from the higher perceptual complexity of faces than that of stimuli traditionally used in the Eriksen Flanker task (letters or signs), leading to a capacity limit in face feature processing

Bird community of inner La Plata City, Argentina

During the years 1991-2000, 101 bird species were recorded in the city of La Plata, Argentina, 47 of which were breeding ones. The most abundant species were: Zenaida auriculata, Columba livia, Funarius rufus, Pitangus sulphuratus, Zonotrichia capensis and Passer domesticus. Columba maculosa, C. picazuro, Furnarius rufus, Turdus rufiventris and Molothrus bonariensis have increased in number, while Passer domesticus has decreased. Zonotrichia capensis may successfully compete for food with Passer domesticus. Sturnus vulgaris and Acridotheres cristatellus are new species in the breeding avifauna of La Plata city.Facultad de Ciencias Naturales y Muse

The relationship between structure and location in the nest of the Yellow-winged Blackbird ( Agelasticus thilius)

La estructura y la ubicación del nido deben maximizar el beneficio que proporciona a la nidada, tanto en el aislamiento del ambiente como en la protección contra predadores. El Varillero Ala Amarilla (Agelasticus thilius) construye nidos abiertos entrelazados a la vegetación palustre en zonas de bañado. Se estudió la altura a la que estas aves construyen su nido y el espesor de sus paredes laterales y de la base, buscando un patrón que correlacione estas características. Los nidos fueron construidos en la mitad inferior de las varas de totora y se encontró una correlación positiva entre la altura de la totora y la distancia del nido a la punta de la vara. Tanto el espesor de la pared como el de la base aumentaron con la distancia entre el nido y la punta de las varas a las que estaban entrelazados, lo cual podría reforzar su estructura permitiéndole soportar los efectos del viento sin romperse. El espesor de la pared fue mayor en los nidos construidos a menor altura pero no se encontró el mismo patrón en el espesor de la base. Los factores ambientales que ponen a prueba la fortaleza de la estructura del nido podrían tener importancia en la determinación de la estructura y la posición de los nidos, mientras que la influencia del riesgo de predación podría ser menor.Nest structure and location must maximize the benefit provided to chicks through isolation from the environment as well as protection against predators. The Yellow-winged Blackbird (Agelasticus thilius) builds open nests intertwined to trowel vegetation in marshlands. The height to which these birds build the nest and the thickness of their lateral walls and base were studied to look for a pattern that relates these characteristics. Nests were built in the lower half of bulrush canes and a positive correlation between height of canes and the distance between the nest and the cane tip was found. The thickness of both nest wall and base increased with the distance between the nest and the cane tip. This could reinforce nest structure improving its resistance to the effect of the wind without damage. Wall thickness was higher in nests built at a lower height, but base thickness was not correlated with this distance. Environmental factors that test the strength of the nest structure may be important in determining nest structure and location, while the influence of predation risk would be lower.Fil: Montalti, Diego. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Zoología de Vertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Graña Grilli, Maricel. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Zoología de Vertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin