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Gut contents of anuran larva (Elachistocleis bicolor, Chaunus schneideri, Odontophrynus americanus, Scinax fuscovarius, and S. granulatus) that coexist in a semi-permanent waterbody from Iguazú National Park (Misiones, Argentina) was analyzed. Our objective was analyse the gut contents of different tadpole species that coexist in the same water body during seasons of minimum and maximum precipitation, to increase the knowledge of the natural history of these tadpoles. Elachistocleis bicolor (obligate-suspension-feeder) it presents only planktonic algae in its gut (92%). In gut of S. fuscovarius and S. granulatus (nektonic) planktonic algae were abundant, especially in the rainy season (14 and 41%). The guts of C. schneideri and O. americanus (benthic) showed sediments (55% and 17.5%) and vegetable fibers (33 and 61%). The largest particle size (< 100 µm) was found in the guts of C. schneideri and the smallest (< 25 µm) in O. americanus and E. bicolor.

We compare the bill morphology of Chilean (Phoenicopterus chilensis), Andean (Phoenicoparrus andinus) and James' (Phoenicoparrus jamesi) Flamingos and give dietary information as evidence of the size-selectivity of their filters. In Chilean Flamingo, the marginal and the outer submarginal lamellae of the upper jaw, together with the outer submarginal lamellae of the lower jaw, may function as a mesh during the outflow and as excluders during the inflow of water. When the beak is closed, the functional mesh has spaces between marginal lamellae with one dimension less than 80 μm in the proximal portion, while spaces are no wider than 959 μm in the curvature and distal portions. In both Phoenicoparrus species, the marginal lamellae of the upper jaw and the outer submarginal lamellae of both jaws probably act as a filter for large prey in the outflow and as excluders during the inflow of water. The inner submarginal lamellae, which have no fringes, lie in series that may form a second sieve for smaller prey. The distance between inner submarginal lamellae of both jaws are no larger than 106 μm in the Andean Flamingo and 56 μm in James' Flamingo. Dietary information on the three species suggests that their filters select different-sized particles. This study extends Jenkin's observations and presents the first complete lamellae description for genus Phoenicoparrus. Morfología del Pico de los Flamencos Sudamericanos Resumen. Describimos y comparamos la morfología del pico de Phoenicopterus chilensis, Phoenicoparrus andinus y Phoenicoparrus jamesi y aportamos información de su dieta como evidencia de la capacidad de selección de tamaños de sus filtros. En Phoenicopterus chilensis, las lamelas marginales y las submarginales externas de la quijada superior, junto con las lamelas submarginales externas de la quijada inferior, funcionarían como filtros en la salida del agua y como exclusores en la entrada. Cuando el pico está cerrado, el tamiz funcional tiene al menos un espacio menor de 80 μm entre las lamelas marginales de la región proximal del pico y espacios no mayores que 959 μm en las regiones de la curvatura y distal. En ambas especies de Phoenicoparrus, las lamelas marginales de la quijada superior y las lamelas submarginales externas de ambas quijadas probablemente actúan como filtros de presas grandes a la salida del agua y como exclusores a la entrada. Las lamelas submarginales internas no presentan ribetes en sus bordes y se disponen en series, que podrían formar un segundo filtro para las presas más pequeñas. La distancia entre lamelas submarginales internas de ambas quijadas no es mayor de 106 μm en Phoenicoparrus andinus, y de 56 μm en Phoenicoparrus jamesi. La información acerca de la dieta de las tres especies sugiere que sus filtros difieren en el tamaño de presa seleccionado. Este trabajo amplía las observaciones de Jenkin y presenta la primera descripción completa de las lamelas del género Phoenicoparrus.

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ABSTRACT/A method for the identification, mapping and evaluation of integrated environmental units is described.This method is applied to the assessment and zoning of a biosphere reserve, in order to establish guidelines for the distribution of conservation and management actions. The method, based on the definition of units according to observable features, enables the diagnosis of qualities of interest for planning and management, with results that can be reproduced by different operators, if certain initial criteria are accepted. Using these criteria, initial descriptive maps can be transformed into prescriptive maps which provide the basis for management decisions.The nature and distribution of the units present in the area is shown. The allocation of land-use activities obtained using the criteria indicated above provides the basis for economic assessment of development plans. A series of conservation and development actions are proposed for the reserve.

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