Rollandia rolland

Abstract: Lake Junin is famous for the abundance and diversity of breeding, staging and wintering waterbirds The lake supports the entire world population of three species or subspecies: Junin Grebe Podiceps taczanowskii, Junin Rail Laterallus tuerosi and the endemic subspecies of the White-tufted Grebe Rollandia rolland morrisoni Surveys undertaken in the 1930s, 1960s, 1970s and 1980s confirmed the lake’s importance in the Andes, however there has been no recent assessment of its waterbird community We undertook waterbird counts between 6 and 20 February 2014 from the lakeshore and by boat Despite using differing survey methods, we nevertheless conclude that the relative abundance of waterbird species has changed dramatically compared to earlier counts Most notably, the Junin Grebe has experienced a major decline since the 1930s when the species was considered extremely abundant and another native fish-eating species the White-tufted Grebe also appears to have declined In contrast the Northern Silvery Grebe Podiceps juninensis, classified as ‘Near Threatened’, has apparently become more abundant Numbers of Puna Teal Spatula puna and Common Gallinule Gallinula galeata seem to have crashed, presumably reflecting the general loss of submerged vegetation In spite of a major decline in waterbirds overall, the Junin area holds numbers of migratory shorebirds, perhaps as a consequence of local hunting restrictions and awareness campaigns Lake Junin is a candidate for listing on the Montreux Record under the Ramsar Convention as a wetland showing serious change in ecological character Management planning should proceed to balance conflicting interests at the lake Actions to re-establish a clear water column by reducing eutrophication (from settlements in the catchment) as well as sedimentation and heavy metals (from upstream mining) will contribute to improving ecological functions and to secure waterbirds including the endemics

Abstract: Los Padres, La Brava and Nahuel Ruca lakes are typical wetlands of the Pampean region. These three shallow lakes share certain limnological features (size, mean depth, littoral macrophytes, among others) and the land usage in their basins (e.g. agriculture, cattle ranching and/or touristic activities). We surveyed the bird community at these three wetlands over three years (May 2006-May 2009), using transects and point counts to characterise their species richness, abundance, community composition and seasonality. We recorded a total of 135 species belonging to 41 families. The Relative Importance Index showed that the neotropic cormorant Phalacrocorax olivaceus, the cattle egret Bubulcus ibis, the white-tufted grebe Rollandia rolland and the white-faced ibis Plegadis chihi are the most representative species. Species richness, species composition and abundance differed between wetlands. Such differences could be attributed to particular factors such as proximity to urban centres or other wetlands, and to the impact of recreational activities. Considering that the Pampean region is currently under strong anthropogenic impacts, the present study contributes to the improvement of management plans that are currently in place or under development.

Abstract: Necropsy on 15 specimens of white-tufted grebe, Rollandiarolland, caught in the Mar Chiquita and Chascomus lagoons (Buenos Aires province), revealed the presence of Contracaecumovale (Linstow, 1907). This nematode shows a marked specificity for podicipediform birds. The specimens were identified from morphological study on features such as cephalic and esophageal structures and caudal papillae, using both optical and scanning electron microscopy. This is the first record of C. ovale parasitizing R. rolland in Argentina.

Abstract: Petasiger argentinensis sp. nov. is described from material found in the intestine of the Great Grebe, Podiceps major (Boddaert) and the White-tufted Grebe, Rollandia rolland Quoy et Gaimard (Podicipediformes, Podicipedidae), from Argentina. The new species is characterized by the head collar armed with 19 spines and by the testes arranged in tandem. These characters are shared with only two Neotropical species of the genus, P. novemdecim Lutz, 1928 and P. combesi Zamparo, Overstreet et Brooks, 2005. Petasiger novemdecim differs from the new species in having a larger body, longer collar spines, larger eggs, a cirrus-sac of similar size to the ventral sucker and almost entirely anterior to it, and vitelline fields confluent ventrally posterior to the ventral sucker. P. combesi differs from the new species in most metrical characters, the shape of the body (antero-posteriorly elongate) and the location of the genital pore (dextral) and the excretory pore (dorsal). This is the first record of a member of the genus Petasiger parasitizing birds from Argentina.