ABSTRACT. The grasslands of southeastern South America (SESA), comprising one of the most extensive grassland ecosystems in the Neotropics, have been negatively impacted by the development of the livestock industry, arable agriculture, and forestry. SESA grasslands have a rich avifauna that includes 22 globally threatened and near-threatened species, and many other species have suffered local population extinctions and range reductions. In addition to habitat loss and fragmentation, grassland birds in SESA are threatened by improper use of agrochemicals, unfavorable fire management regimes, pollution, and illegal capture and hunting. Studies to date have provided information about the distribution of grassland birds, the threats populations face, and the habitat requirements of some threatened species, but more information is needed concerning dispersal and migration patterns, genetics, and factors that influence habitat use and species survival in both natural and agricultural landscapes. There are few public protected areas in the region (1% of original grasslands), and many populations of threatened grassland birds are found on private lands. Therefore, efforts to preserve grassland habitat must reconcile the interests of land owners and conservationists. Current conservation efforts include establishment of public and private reserves, promotion of agricultural activities that reconcile production with biodiversity conservation, development of multilateral conservation projects across countries, and elaboration of action plans. Measures that result in significant losses to private land owners should include economic compensation, and use of economic incentives to promote agriculture and forestry in native grassland areas should be discouraged, especially in priority areas for grassland birds. Although more studies are needed, some actions, particularly habitat protection and improved management of public and private lands, should be taken immediately to improve the conservation status of grassland birds in SESA.RESUMEN. Ecología y conservación de aves de pastizal en el SE de Sudamérica: una revisión Los pastizales del sureste de Sudamérica (SESA), que conforman uno de los mayores ecosistemas de pastizales en el Neotrópico, han sufrido transformaciones importantes debido al desarrollo de la industria ganadera, la agricultura y la forestación. Los pastizales del SESA tienen una rica avifauna que incluye 22 especies amenazadas o casi amenazadas y muchas otras han sufrido extinciones poblacionales locales y reducciones muy sustanciales de sus rangos de distribución. Además de la pérdida de hábitat y la fragmentación, las aves de pastizal del SESA están amenazadas por el uso inapropiado de agroquímicos, regímenes desfavorables de manejo del fuego, contaminación, captura y caza ilegales. Los estudios al día de hoy han generado información sobre la distribución de aves de pastizal, las amenazas que sus poblaciones enfrentan y de los requerimientos de hábitat de algunas especies amenazadas, pero aun es necesaria más...

Selection acted repeatedly on regions that may regulate the expression of genes underlying coloration differences in seedeaters.

ABSTRACT. Revision and updating of the list of birds of Rio Grande do Sul, Brazil. The list of birds of the state of Rio Grande do Sul (281,749 sq. km), southern Brazil, is revised and updated. Species were included in the list according to two main criteria: (i) occurrence in the state documented with tangible evidence -study skin or complete specimen, photograph, video or vocal recording -published in the literature or available for independent verification in scientific collections or archives of public access, or (ii) at least one state record supported by non-material evidence allowing an unequivocal diagnosis of the taxon, such as a circumstantiated report, published or provided to the authors, containing a detailed description of or reference to the diagnostic features observed. Species mentioned for the state that do not conform to these criteria were not included in the main list and were regarded as probable or hypothetical, according to the evidence available and the distributional coherence of the existing records. The final list comprises 661 species, of which 649 are documented by physical evidence. Another 10 and 16 species are listed as probable and hypothetical, respectively. Compared with the previous list, 44 species were added and seven were excluded or substituted, resulting in a net increase of 37 species. Fregetta grallaria (Vieillot, 1818), Polytmus guainumbi (Pallas, 1764), Nonnula rubecula (Spix, 1824), Stymphalornis acutirostris Bornschein, Reinert & Teixeira, 1995, Fluvicola albiventer (Spix, 1825, and Xenopsaris albinucha (Burmeister, 1869) are mentioned for the state for the first time. The number of species added since the last review corresponds to an average increase of slightly more than four species per year. By examining the recent additions in retrospect, it is clear that the number of bird species known to occur in Rio Grande do Sul should continue to grow at a similar rate over the next decade or so. In view of this, some guidelines for improving future revisions of the state checklist are proposed. In order to better understand new occurrences of birds over time, the use of adequate criteria to distinguish range extensions from range expansions, and instances of vagrancy from pseudo-vagrancy, is recommended.KEYWORDS. Avifauna, distribution records, new occurrences, documentation, collections. RESUMO.Neste artigo, a lista das aves do estado do Rio Grande do Sul (281.749 km 2 ) é revisada e atualizada. A inclusão de espécies na lista seguiu dois critérios principais: (i) ocorrência no estado documentada por evidência tangível -pele ou espécime completo, foto, vídeo ou gravação de áudio -publicada na literatura ou disponível para verificação independente em coleções ou arquivos científicos de acesso público, ou (ii) pelo menos um registro no estado acompanhado de evidência não-material que permita a identificação segura do táxon, tal como um relato circunstanciado, publicado ou fornecido aos autores, contendo descrição detalhada ou referência às características diagnósticas ...

Identifying the ecological factors that shape parasite distributions remains a central goal in disease ecology. These factors include dispersal capability, environmental filters and geographic distance. Using 520 haemosporidian parasite genetic lineages recovered from 7,534 birds sampled across tropical and temperate South America, we tested (a) the latitudinal diversity gradient hypothesis and (b) the distance–decay relationship (decreasing proportion of shared species between communities with increasing geographic distance) for this host–parasite system. We then inferred the biogeographic processes influencing the diversity and distributions of this cosmopolitan group of parasites across South America. We found support for a latitudinal gradient in diversity for avian haemosporidian parasites, potentially mediated through higher avian host diversity towards the equator. Parasite similarity was correlated with climate similarity, geographic distance and host composition. Local diversification in Amazonian lineages followed by dispersal was the most frequent biogeographic events reconstructed for haemosporidian parasites. Combining macroecological patterns and biogeographic processes, our study reveals that haemosporidian parasites are capable of circumventing geographic barriers and dispersing across biomes, although constrained by environmental filtering. The contemporary diversity and distributions of haemosporidian parasites are mainly driven by historical (speciation) and ecological (dispersal) processes, whereas the parasite community assembly is largely governed by host composition and to a lesser extent by environmental conditions.

Geographic variation in environmental conditions as well as host traits that promote parasite transmission may impact infection rates and community assembly of vector‐transmitted parasites. Identifying the ecological, environmental and historical determinants of parasite distributions and diversity is therefore necessary to understand disease outbreaks under changing environments. Here, we identified the predictors and contributions of infection probability and phylogenetic diversity of Leucocytozoon (an avian blood parasite) at site and species levels across the New World. To explore spatial patterns in infection probability and lineage diversity for Leucocytozoon parasites, we surveyed 69 bird communities from Alaska to Patagonia. Using phylogenetic Bayesian hierarchical models and high‐resolution satellite remote‐sensing data, we determined the relative influence of climate, landscape, geography and host phylogeny on regional parasite community assembly. Infection rates and parasite diversity exhibited considerable variation across regions in the Americas. In opposition to the latitudinal gradient hypothesis, both the diversity and prevalence of Leucocytozoon parasites decreased towards the equator. Host relatedness and traits known to promote vector exposure neither predicted infection probability nor parasite diversity. Instead, the probability of a bird being infected with Leucocytozoon increased with increasing vegetation cover (NDVI) and moisture levels (NDWI), whereas the diversity of parasite lineages decreased with increasing NDVI. Infection rates and parasite diversity also tended to be higher in cooler regions and higher latitudes. Whereas temperature partially constrains Leucocytozoon diversity and infection rates, landscape features, such as vegetation cover and water body availability, play a significant role in modulating the probability of a bird being infected. This suggests that, for Leucocytozoon, the barriers to host shifting and parasite host range expansion are jointly determined by environmental filtering and landscape, but not by host phylogeny. Our results show that integrating host traits, host ancestry, bioclimatic data and microhabitat characteristics that are important for vector reproduction are imperative to understand and predict infection prevalence and diversity of vector‐transmitted parasites. Unlike other vector‐transmitted diseases, our results show that Leucocytozoon diversity and prevalence will likely decrease with warming temperatures.

Cities are highly modified environments in which the only areas that resemble natural landscapes are urban parks with low human population density. Attempts are frequently made to maintain high bird diversity in cities for aesthetic or educational reasons. However, it remains unclear whether local site characteristics are important in determining bird assemblage composition or whether simplification of the assemblage is an inevitable consequence of the changes associated with human population density. From May 1998 to December 1999, we undertook bird counts at 521 points in Porto Alegre, Rio Grande do Sul, southern Brazil. Our main goal was to understand the pattern of distribution of the bird species richness and density within the city and determine which variables most affect species assemblages. We recorded 132 species belonging to 43 families that are common in Rio Grande do Sul and obtained quantitative data on 121 species in survey sites. The two most abundant species (House Sparrow, Passer domesticus and Rock dove, Columba livia) were exotics. Analysis based on a reduced subset of 134 points surveyed in spring/early summer suggested that there was a North-south gradient in assemblage structure. Variation in assemblage structure was also affected by the number of trees, urban noise and human population density. However, human population density had a much smaller effect on richness and assemblage structure than variables subject to management, such as tree density and noise levels. These Urban Ecosyst (2011) 14:341-360

Scytalopus and the recently erected Eleoscytalopus are among the Neotropical groups of birds whose taxonomy is most difficult to resolve given their very conservative morphology. We investigated the phylogeny and species limits of Eleoscytalopus and the eastern Scytalopus using two mitochondrial genes and two nuclear introns of multiple individuals from all species of these groups. The eastern Scytalopus are separated in three well defined clades also supported by morphological or vocal characteristics, although the relationships between these clades could not be resolved. We found several allopatric and very divergent lineages in these genera whose characteristics are consistent with species-level divergence, especially in S.speluncae. The great divergence between E. psychopompus and its sister species supports the former as a valid species. Our results corroborate the importance of the Bahia refuge as an avian center of endemism.

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