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

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

Aspectos fisiológicos e bioquímicos da glândula uropigial das aves

This review discusses different aspects of the uropygial gland of birds. The gland exhibits a striking morphological diversity in size, shape and presence/absence of tufts of feathers. It was shown that acidic mucins, neutral lipids, glycolipids and phospholipids are normal components of secretion. Several morphological and physiological aspects of the gland were studied on Rock Pigeon Columba livia Gmelin, 1879. The amount of the uropygial gland secretion, its lipid content and fatty acids profile were determined. The extracted lipid mixture contained of C14 to C20 fatty acids, mostly unsaturated; the saturated fatty acids were mainly 14:0, 16:0 and 18:0. No correlation was found between the size of the gland and the aquatic/terrestrial nature of the species. Ablation of the gland did not affect survival, body weight, feeding rate and serum cholesterol, total lipids or calcium levels after 32-120 days. The possible role of the gland in the protection against lipophilic compounds was discussed. The function of the gland is still a subject of controversy. It is accepted that its secretion confers water-repellent properties on the feather coat and maintain the suppleness of the feathers. Other physiological roles of the gland secretion may be associated to pheromone production, control of plumage hygiene, thermal insulation and defence against predators. Concerning the endocrine regulation of the uropygial function, there is scarce information presenting evidence for steroid regulated mechanisms.Esta revisão discute diferentes aspectos da glândula uropigial das aves. A glândula exibe uma chamativa diversidade morfológica de tamanho, forma e presença/ausência de um tufo de penas. A glândula mostrou mucinas ácidas, lipídios neutros, glicolipídios e fosfolipídios como componentes normais de sua secreção. Diversos aspectos morfológicos e fisiológicos da glândula foram estudados na pomba doméstica Columba livia. Foi determinada a quantidade de secreção da glândula uropigial, seu conteúdo lipídico e o perfil de ácidos sebosos. A mistura lipídica extraída contém ácidos graxos C14 a C20, principalmente não saturados; os ácidos graxos saturados foram principalmente 14:0, 16:0 e 18:0. Não se encontrou correlação entre o tamanho da glândula e a natureza aquática/terrestre das espécies. A ablação da glândula não afetou a sobrevivência, peso corporal, alimentação e os níveis séricos de colesterol, lipídios totais ou cálcio depois de 32-120 dias. Discute-se o possível papel da glândula na proteção contra compostos lipofílicos. A função da glândula é ainda tema de controvérsia. Aceita-se que sua secreção confere às penas propriedades repelentes à água e as mantém flexíveis. Outras funções fisiológicas da secreção glandular podem estar associadas com a produção de feromonas, controle da higiene da plumagem, isolamento térmico e defesa contra predadores. Com relação à regulação endócrina da glândula, tem-se escassa informação, apresentando evidência de mecanismos de regulação de esteróides.Facultad de Ciencias Naturales y Muse

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

Is it possible for a Procellariiform to raise two chicks? A case of chick adoption in Southern Giant petrels Macronectes giganteus in the South Shetland Islands, Antarctica

We report on the adoption of a Southern Giant Petrel Macronectes giganteus chick by a breeding pair on 25 de Mayo Island (King George Island), South Shetland Islands, Antarctica. Our observations showed both chicks received similar amounts of food, but there were differences in their growth rates that could be explained by their gender. After the third week of adoption, aggressive behaviors were common between chicks, usually expressed through regurgitation. This resulted in a low rate of growth in both chicks. Neither chick fledged, and both were found dead near the colony seven weeks after adoption. The constant fights between them could be one of the causes of their death, particularly if death resulted from excessive regurgitation. Although exclusion of unrelated chicks at nest sites has not been reported in M. giganteus, chick adoption seems to have no clear benefits and may contribute to brood failure.Fil: Archuby, Diego Ignacio. Ministerio de Relaciones Exteriores, Comercio Interno y Culto. Dirección Nacional del Antártico. Instituto Antártico Argentino; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Coria, Néstor Rubén. Ministerio de Relaciones Exteriores, Comercio Interno y Culto. Dirección Nacional del Antártico. Instituto Antártico Argentino; ArgentinaFil: Harrington, Ana. Ministerio de Relaciones Exteriores, Comercio Interno y Culto. Dirección Nacional del Antártico. Instituto Antártico Argentino; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Fusaro, Bruno. 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; ArgentinaFil: Montalti, Diego. Ministerio de Relaciones Exteriores, Comercio Interno y Culto. Dirección Nacional del Antártico. Instituto Antártico Argentino; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Favero, Marco. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentin

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

Local bird traits match fruit traits of two alien plants in urban fruit-frugivore interactions

La dispersión mediada por aves promueve la invasión de muchas especies de plantas exóticas. Típicamente, este mutualismo se compone de un ensamble generalista de aves frugívoras en el cual el acople de rasgos morfológicos entre especies de aves y plantas se considera pobre como resultado de una baja adaptación recíproca. A pesar de esta idea de larga data, el acople de rasgos entre aves locales y plantas exóticas no ha sido investigado. Evaluamos el acople de caracteres mediante la comparación de rasgos funcionales en un espacio multidimensional para aves frugívoras locales (tamaño del pico, ala y tarso) y dos plantas invasoras (tamaño del fruto y semilla, forma del fruto y semilla) en un área urbana. Para esto, medimos los rasgos funcionales de las aves en especímenes de museo y los rasgos funcionales de las plantas en individuos localizados en el área de estudio. Encontramos un acople de rasgos significativo entre las aves y las plantas invasoras (las aves frugívoras interactuaron con aquellas especies de plantas invasoras correspondientes en términos morfológicos), y una correlación positiva entre la especialización morfológica y la funcional de las especies de aves (morfologías extremas tuvieron roles funcionales especializados). Contrario a la idea de que los mutualismos de plantas invasoras son mediados por dispersores de semillas generalistas sin un ajuste fino entre rasgos de las aves y plantas, nuestros resultados indican que especies con diferentes morfologías se alimentan de especies de plantas distintivas. Estos resultados resaltan la importancia de estudiar el rol funcional de las aves locales en interacciones mutualistas con especies de plantas exóticas, y cómo estos roles funcionales pueden promover los procesos de invasión.Bird-mediated seed dispersal enhances invasions of many alien plant species. Typically, this mutualism is composed of a generalist assemblage of frugivorous birds in which morphological trait matching between bird and plant species is often thought to be poor due to low reciprocal adaptation. Despite this long-held notion, trait matching between local birds and alien plants has not been investigated. Here, we assessed trait matching by comparing functional traits in multidimensional space for local birds (bill, wing and tarsus size) and two alien invasive plants (fruit and seed size, fruit and seed shape) in an urban area. To do this, we measured bird functional traits in museum specimens and plant functional traits in individuals located in the study area. We found significant trait matching between birds and alien invasive plants (i.e., frugivorous birds interacted with morphologically corresponding invasive plant species). In addition, we detected a positive correlation between morphological and functional specialization of bird species so that extreme morphologies played specialized functional roles. Contrary to the idea that alien plant mutualisms are mediated by generalized seed dispersers without a close match between bird and alien plant traits, our results indicate that species with different morphologies forage on distinct plant species. These findings highlight the importance of studying the functional role of local birds in mutualistic interactions with alien invasive plants, and how these functional roles may promote invasion processes.Fil: Palacio, Facundo Xavier. 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: 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; Argentin

Autumn seabird observations off the South Shetland Islands

Los estudios de aves marinas entre las Islas Shetland del Sur y el norte de la península Antártica son numerosos durante el verano, mientras fuera de esta época son escasos en esta zona. El objetivo de este estudio fue registrar las especies de aves presentes en otoño en la zona comprendida entre el norte de la península Antártica y las islas Shetland del Sur. Las observaciones fueron hechas abordo del Rompehielos Alte. lrizar; se realizaron censos de 10 minutos seguidos de lO minutos de intervalo. durante el fotopedodo. Se calculó el índice de diversidad de Shannon. Fueron registradas 13 especies; se relaciona la aparición de estas aves en la zona en esta época con variables ambientales.SeabirdsSouth Shetland IslandsAntarcticaAutum

Variación estacional y efecto de vegetación exótica invasora sobre dos comunidades de aves en el noreste de la provincia de Buenos Aires, Argentina

We studied seasonal patterns and the effect of non-native invasive vegetation on bird communities in woodland and adjacent herbaceous-shrub areas in north-east Buenos Aires province, Argentina. Diversity, species richness and density of bird species were higher in spring and summer than in fall and winter in both habitat types. We also found significant between-habitat differences in bird species composition in winter, spring and summer. Seasonal variations were mainly due to changes in the abundance of migrants, whereas bird species segregation to each habitat was mostly explained by non-native vegetation structure. Most species were associated with sites dominated by either Dipsacus fullonum or Gleditsia triacanthos, whereas only four species were associated with high Ligustrum lucidum densities. These results show that despite the dominance of non-native invasive plant species at our study site, vegetation structure is still the main factor structuring bird communities. In addition, some plant species, such as L. lucidum, seem to have a negative effect on bird communities by reducing their diversity, whereas others, such as D. fullonum and G. triacanthos, seem to have a positive effect compared to L. lucidum by providing not only food resources during a great part of the year but also nest sites.Estudiamos los patrones estacionales y el efecto de vegetación exótica invasora en comunidades de aves de bosque y zonas herbá- ceo-arbustivas adyacentes en el noreste de la provincia de Buenos Aires, Argentina. Diversidad, riqueza y densidad de aves fueron mayores en primavera-verano que en otoño-invierno en ambos tipos de ambiente. Además, encontramos diferencias significativas entre hábitats en la composición de especies en invierno, primavera y verano. Las variaciones estacionales en los atributos comunitarios se debieron principalmente a cambios en la abundancia de aves migratorias, mientras que la segregación de especies en ambos ambientes estuvo explicada en gran parte por la estructura de la vegetación de especies exóticas invasoras. La gran mayoría de las especies de aves estuvieron asociadas a sitios dominados por Dipsacus fullonum ó Gleditsia triacanthos, mientras que sólo cuatro especies estuvieron asociadas a sitios con altas densidades de Ligustrum lucidum. Nuestros resultados muestran que a pesar de la dominancia de vegetación exótica invasora en nuestro sitio de estudio, la estructura de la vegetación es el principal factor que estructura las comunidades de aves. Asimismo, algunas especies exóticas, como L. lucidum, tendrían un efecto negativo sobre las comunidades de aves al disminuir su diversidad, mientras que otras, como D. fullonum y G. triacanthos, tendrían un efecto positivo en comparación con L. lucidum al proveer no solo alimento durante gran parte del año, sino también sitios de nidificación.Fil: Palacio, Facundo Xavier. Fundación Miguel Lillo; 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