45 research outputs found
Avian haemosporidian infections in rufous-collared sparrows in an Andean dry forest: diversity and factors related to prevalence and parasitaemia
Despite intensive research during the last few decades, understanding of ecological and physiological factors related to haemosporidian infections in birds is still fragmentary. Since more model organisms are needed in order to understand these infections in the wild, we analysed avian haemosporidian infections in the rufous-collared sparrow (Zonotrichia capensis, Emberizidae) in a dry forest of the Ecuadorian Andes. Parasite diversity was screened using molecular and morphological approaches. By molecular diagnosis, we identified three linages that were phylogenetically placed in the context of molecular haemosporidian diversity and associated with a morphospecies. By microscopy, we identified five described morphospecies and one additional undescribed morphospecies. We found that avian haemosporidian prevalence on the study site was 76.3%. Additionally, we used a series of generalized linear models to explore the potential relationship of parasite prevalence and parasitaemia with a set of variables related to physiological and environmental conditions. Although our results revealed associations of haemosporidian infections with precipitation, age and sampling site, the models only explained a small fraction of the variation
Blood parasites infecting the Hoatzin (Opisthocomus hoazin), a unique neotropical folivorous bird
The Hoatzin (Opisthocomus hoazin) is the only extant member of the order Opisthocomiformes. This unique South American bird lives in the riparian lowland vegetation characteristic of the Amazon and Orinoco basins. Hoatzins nest in communal social units close to water bodies; they are strictly folivores being the only bird with pregastric fermentation in the crop. Because of the complex logistics involved in capturing this bird, there is a knowledge gap on its parasites. This study documents two distant lineages of haemosporidian parasites (Plasmodium spp.) in a juvenile and two adults sampled in the Cojedes state, Venezuela. Although negative by microscopy, the parasite identification was possible by using molecular methods. We estimated the phylogenetic relationships on the parasite cytochrome b (cytb, 480 bp) gene and the mitochondrial DNA. We found one of the parasites lineages in two individuals (nestling and adult), and the corresponding fragment of cytb was identical to a one found in Wood Stork (Mycteria americana) from Brazil. The other lineage, found in an adult, has an identity of 469 out of 478 bp (98%) with Plasmodium sp. GAL-2012 (isolate THAMB08) from Brazil. Although a morphological description of these parasites was not possible, this is the first molecular study focusing on Hoatzin haemosporidian parasites and the first documentation of Plasmodium infections in the Hoatzin from Venezuela. Furthermore, we reported microfilaria in two adults as well as hematological parameters for six individuals. Information on hematological parameters could contribute to establishing the necessary baseline to detect underlying conditions, such as infections, in this bird species
DETERMINACIÓN DE SEXO EN AVES MEDIANTE HERRAMIENTAS MOLECULARES
<p><strong><span style="font-family: verdana; font-size: x-small;">RESUMEN </span></strong></p> <p><span style="font-family: verdana; font-size: x-small;">La ausencia de dimorfismo sexual en los estadios juveniles y durante la edad adulta de gran cantidad de especies de aves, dificulta o imposibilita la determinación del sexo basados en el fenotipo. El empleo de marcadores moleculares para determinar el sexo de las aves es una herramienta útil debido a la exactitud y rapidez de los resultados y a su vez se constituye en un método que minimiza el estrés durante la toma de muestra, comparado con otras técnicas invasivas que pudieran afectar la salud o estabilidad biológica del animal. La determinación temprana del sexo en aves resulta de especial relevancia cuando se consideran programas de conservación <em>ex situ</em>, producción, explotación y estudios de ecología de poblaciones. Esta revisión presenta las metodologías usadas para determinar el sexo, haciendo especial énfasis en herramientas moleculares, presentando sus ventajas y limitaciones. </span></p> <p><span style="font-family: verdana; font-size: x-small;">Palabras clave: dimorfismo sexual, aves, CHD, tipificación molecular cromosoma W, cromosoma Z.</span></p><hr size="1" /><p><span style="font-family: verdana; font-size: x-small;"><strong>ABSTRACT</strong> </span></p> <p><span style="font-family: verdana; font-size: x-small;">The lack of sexual dimorphism in nestling, juvenile or adult birds of large number of avian species, makes it difficult or impossible sex determination based on phenotipic characteristics. To use molecular markers for bird sex determination is a rapid and safe procedure; moreover this methodology minimizes the stress during sampling, compared to other invasive techniques that could affect the health or biological stability of the animal. The early sex determination in birds is of particular importance when considering <em>ex situ </em>conservation programs, production, exploitation or population ecology studies. This review presents the methodologies used to sex determination, making emphasize on molecular tools, showing its advantages and limitations. </span></p> <p><span style="font-family: verdana; font-size: x-small;">Keywords: sexual dimorphism, birds, CHD, molecular typing, W chromosome, Z chromosome </span></p>
Hemoparásitos aviares Avian Haematoza
El parasitismo representa una de las formas de vida más exitosas sobre el planeta, existen más de 31.000 especies de protozoarios reportadas, y se calcula que falta porinvestigar y describir cerca del 80%. Entendiendo biodiversidad como un términoaplicado para describir el número, variedad y variabilidad de organismos, surge lainquietud ¿cuál es la biodiversidad de los organismos parasíticos. Desafortunadamente esta pregunta no se puede contestar con la información actual; ya sea por laenorme diversidad y riqueza del grupo, por la falta de estudios o por una combinaciónde ambas. En la actualidad, el conocimiento de los protozoarios está ligado a suimportancia clínica y económica, ej. existe información detallada en algunas especiesde coccidios, flagelados y amebas de mamíferos, mientras que la investigación en hemosporidios de aves y reptiles es limitada. En Colombia específicamente los estudiosen hemoparásitos en vida silvestre son muy reducidos, a pesar de poseer una grandiversidad organísmica y ecosistémica
Hemoparásitos aviares de los llanos orientales colombianos
Un total de 315 aves, pertenecientes a 75 (23 familias) de Villavicencio y San Miguel (Meta, Colombia) fueron examinadas para hematozoarios, donde 50 aves (15.9%) presentaron uno o mas hemoparasitos. Microfilaria fue el hematozoario más encontrado, seguido numéricamente por: especies de Haemoproteus, Plasmodium y Trypanosoma y finalmente par un ejemplar de Hepatozoon. El estudio incluye 15 nuevos registros hospedero-parasito para el mundo y 18 para Colombia y 8 especies de aves fueron examinadas para hemoparasitos por primera vez. La baja prevalencia registrada por este estudio coincide con los estudios para otras zonas del Neotrópico y Colombia
SHORT COMMUNICATION - Blood Parasites in Some Birds from Eastern Plains of Colombia
A total of 315 birds representing 75 species (23 families) from
Villavicencio and San Miguel (Meta, Colombia) were examined for
haematozoa. Fifty birds (15.9%) harbored blood parasites. Microfilariae
were the most common haematozoans encountered, followed by species of
the genera Haemoproteus , Plasmodium and Trypanosoma
. This survey included 15 new host-parasite records and 8
species of birds that were examined for haematozoa for the first time.
The prevalence registered in this research was similar to others
recorded in the Neotropical region, but in sharp contrast with the
prevalence of blood parasites in other major land masses
REGISTROS NUEVOS O POCO CONOCIDOS DE AVES MIGRATORIAS EN LA LAGUNA DEL OTÚN, PARQUE NACIONAL NATURAL LOS NEVADOS, RISARALDA, COLOMBIA
Colombia es un sitio importante para las aves migratorias. Sin embargo, aún falta mucho conocimiento de dónde estas se encuentran durante su paso o permanencia por el país y cuáles utilizan los páramos. Registramos nuevas especies de aves migratorias para la laguna del Otún, inmersa en un complejo de humedales declarados sitio Ramsar desde el 2008. La laguna está localizada en el Parque Nacional Natural Los Nevados a 3932 msnm, en ecosistema de páramo, en la Cordillera Central de los Andes de Colombia. Durante cinco salidas entre 2010 y 2012 se registraron cuatro nuevas especies de aves migratorias para el parque: Anas acuta, Pandion haliaetus, Riparia riparia y Dendroica petechia. Adicionalmente, se registró una ampliación del rango altitudinal para dos especies migratorias que solo habían sido registradas en la región a menos de 3500 msnm: Tringa flavipes e Hirundo rustica. Estas observaciones sugieren que dichas especies podrían tolerar condiciones de alta montaña y utilizar el páramo. Es necesario estudiar a fondo las dinámicas migratorias y el uso de hábitat de alta montaña por las aves migratorias
Oviposition behavior and microstructure of the eggs of Simulium dinellii (Joan) (Diptera: Simuliidae)
Little is known about the oviposition habits and egg structure of Neotropical members of the Simuliidae family. The oviposition behavior of Simulium dinellii (Joan) was observed near at Otún Quimbaya, Colombia. Small groups of females hovered about 2 cm above the water surface to oviposit. Some of these females had been capture and the eggs were obtained. These eggs were counted, measured and processed by scanning electron microscopy. Subtriangular eggs had a latticework of polygons on the endochorionic surface. Chorionic differences between the eggs of S. dinellii and the few previously studied species suggest potential taxonomic value of egg microstructure