ABSTRACT. Reduction in taxonomic and functional bird diversity in an urban area in Southern Brazil. Urbanization is a globally process studied and considered one of the most drastic environmental disturb on biodiversity. This study aimed to evaluate how different intensities of urbanization act in the structure of birds in a medium size city inserted in a wetland area. In addition to the traditional metrics richness, abundance and taxonomic composition, it was found as the functional diversity and redundancy of birds are influenced by urban gradient. The urban area studied was the Pelotas city (31°46''S, 52°20'W) situated at the southernmost part of Brazil in a humid region of Pampa biome. A total of 216 fixed observation points along an urbanization gradient were used to sample the avifauna and four independent variables: number of trees, number of buildings with two or more floors, presence of aquatic habitat, and presence of open habitat. Functional traits of species characterized the biomass, diet, forage substrate and nesting substrate. The richness, abundance and functional diversity of avifauna were negatively related to the increase of urban intensity while the redundancy, different from the expected, did not respond to the urban gradient. The traits related to the areas with more intense urbanization (building with two or more floors) were: preference for foraging in the air, omnivory and cavity nesting. Areas with less intense urbanization (more trees and open habitats) were related to the preference for nesting on vegetation and in lower sites, and carnivory. The study showed the importance of the presence of open and aquatic habitats for the avifauna, landscape features typically not cited in urban studies, which highlight the need to adequate the mitigation actions for conservation efforts inside urban habitats according to the regional pool of species.KEYWORDS. Biotic homogenization, Rao's functional diversity, wetlands, Pampa biome. RESUMO.A urbanização é um processo globalmente estudado e considerado um dos distúrbios mais drásticos sobre a biodiversidade. Este estudo teve como objetivo avaliar como diferentes intensidades de urbanização atuam na estruturação da avifauna em uma cidade de tamanho médio e inserida em região de área úmida. Além das métricas tradicionais de riqueza, abundância e composição taxonômica, verificou-se como a diversidade e redundâncias funcionais das aves são influenciadas pelo gradiente urbano. A área urbana estudada foi a cidade de Pelotas (31°46'S, 52°20'W), extremo sul do Brasil, que está inserida em uma área úmida do bioma Pampa. A amostragem das aves e a medida das variáveis urbanas (número de árvores, número de construções de até dois andares ou de mais de dois andares, presença de ambiente aquático e presença de ambiente aberto) foram realizadas em 216 pontos fixos de observação que foram marcados em diferentes intensidades de urbanização. Os atributos funcionais utilizados para caracterizar as espécies foram os relacionados à massa, dieta, substrato de forrageame...

assemblages in the urban area in the city of Pelotas, Rio Grande do Sul, Brazil. Biota Neotrop. 13(2): http://www.biotaneotropica.org.br/v13n2/en/abstract?inven tory+bn01113022013Abstract: Urbanization causes changes in the composition and diversity of biotic communities. The goals of this work are to present a list of bird species that use the urban area in the city of Pelotas (RS), in the southernmost end of Brazil, and to describe the bird assemblages structure underlining the richness, composition, and relative abundance of species and their seasonal variability. Data collection took place between October 2007 and September 2008, at 216 fixed points, distributed in groups of 6 equidistant points at each 200 meters in streets with varied levels of urbanization, sampled once a season. The observer stayed for 8 minutes at each point, resulting in a sampling effort of 28.8 hours each season and 115.2 hours during the year. A total of 9,595 contacts of 84 bird species were found, belonging to 34 families and 14 orders. In regard to relative abundance, 72 species presented less than 200 contacts; 7 presented between 200 and 1,000; and 4 presented over 1,000 contacts. The species with more than 1,000 contacts were Furnarius rufus, Columba livia, Myiopsitta monachus, and Pitangus sulphuratus, accounting for 5,136 contacts. In all 84 species, 67 were present in less than 20% of the sampled points; 7 were registered at between 20-40% and between 40-60% of the points; and 3 were sighted at between 80-100% of the observation points. Species with the highest frequency of occurrence were P. sulphuratus, Passer domesticus, and F. rufus. Total richness ranged from 55 species in the fall to 61 in the winter. Of the 84 species, 21 were present in 1 season, 17 in 2, 9 in 3, and 37 were present in all four seasons. The season with the highest relative abundance was spring, with 2,936 contacts; the one with the least abundance was autumn, with 2,149 contacts. The bird assemblages presented a representative richness relative to the region, though very few species are abundant and well distributed. Such pattern may be a reflection of the low quality and heterogeneity of the urban matrix, which has few parks and green areas, no reserves with native vegetation and lakes, and a low degree of tree coverage. Resumo: A urbanização altera a composição e diversidade das comunidades bióticas. Os objetivos do trabalho são apresentar a lista de espécies de aves que utilizam a área urbana do município de Pelotas (RS), no extremo sul do Brasil, e descrever a estrutura da assembleia com ênfase na riqueza, composição e abundância relativa de espécies e suas variações sazonais. A coleta de dados ocorreu entre outubro de 2007 e setembro de 2008, em 216 pontos fixos de observação distribuídos em grupos de seis pontos em ruas com todos os graus de urbanização, que foram amostrados uma vez por estação. O observador permaneceu oito minutos em cada um dos pontos, o que resultou no esforço amostral de 28,8 horas em cada estação e 115,2 horas no ano. For...

triangulation as anti-predatory mechanism in snakes. Biota Neotrop. 12(3): http://www.biotaneotropica.org.br/v12n3/en/ abstract?short-communication+bn01912032012Abstract: Anti-predator mechanisms in snakes are diverse and complex, including mimetic behavior. Some snakes triangulate their head, probably mimicking other more dangerous snakes. However, there is a lack of studies that demonstrate the effectiveness of this behavior with natural predators. The aim of this study was to verify, using artificial snakes, if snakes with triangular heads are less susceptible to attack by predators, and if predatory attack is targeted to the head of serpents. Artificial snakes were systematically arranged on a road border. The rate of attacked models was 48.71%. Number of attacks on models with rounded head was significantly higher than in models with triangular head. There was a significant difference between the places of attack on the snakes in relation to different head shapes. Therefore, snakes that have head triangulation may be a less frequent target of attacks by predators than those without such behavior. Keywords: artificial models, defensive behavior, mimicry, predation rate, reptiles. Resumo: Mecanismos anti-predação em serpentes são diversos e complexos, incluindo comportamentos miméticos. Algumas serpentes triangulam a cabeça, possivelmente mimetizando outras serpentes mais perigosas. No entanto, são escassos os estudos demonstrando a eficiência deste comportamento frente a predadores naturais. O objetivo deste estudo foi verificar, utilizando serpentes artificiais, se os indivíduos com cabeça triangular são menos suscetíveis ao ataque de predadores e, se o ataque predatório é direcionado à cabeça das serpentes. Serpentes artificiais foram dispostas sistematicamente na margem de uma estrada. A taxa de modelos atacados foi 48,71%. O número de ataques em modelos de cabeça arredondada foi significativamente maior do que nos modelos com cabeça triangular. Houve diferença significativa entre as partes atacadas nas serpentes quando comparados aos diferentes formatos de cabeça. Portanto, as serpentes que possuem triangulação da cabeça podem ser um alvo menos frequente de ataques por predadores do que as que não possuem esse tipo de comportamento. Palavras-chave: modelos artificiais, comportamento defensivo, mimetismo, taxa de predação, répteis. Biota Neotrop., vol. 12, no. 3 spatial homogeneity of the surrounding vegetation. The models were exposed for 17 hours, overnight, and collected the next morning. In field, each model was analyzed for attack presence, number of attacks, part of the model that suffered the attack (head or other parts of the body) and type of attack. Data analysis was performed in the program Past (Hammer et al. 2001) using Chi-square test (α = 0.05) to compare proportion of attacks on triangular and round head snakes models and proportion of attacks in the head and body between the two kinds of snake models. ResultsFrom the 80 snake models, one of each treatment was excluded from analysis bec...

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