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

Summary 1.Although it is widely assumed that protected areas conserve species that would not survive elsewhere, this assumption is seldom tested. The aim of the study was to determine the respective roles of a nature reserve and commercial and subsistence rangeland in preserving terrestrial arthropods and reptiles in xeric succulent thicket in the Eastern Cape, South Africa. 2. Faunal diversity on a nature reserve (the Great Fish River Reserve Complex) was compared with a historically overgrazed commercial farm, an intensively managed, conservatively stocked commercial farm and a communal grazing area. Terrestrial arthropods and reptiles were caught in paired pitfall traps inside and outside the nature reserve, specimens being sorted into recognizable taxonomic units (RTU). The taxa occurring in each land management unit were compared using RTU diversity, a hierarchical richness index (HRI), community similarity and uniqueness. 3. The nature reserve contained more RTU and a greater HRI than adjacent land for most arthropod groups, and also supported more unique taxa than the other study localities. 4. Snakes and lizards, in contrast, were almost twice as abundant in the communal grazing area as elsewhere, although reptile species diversity was similar at all localities. 5. Each individual locality contained fewer than 62% of the total number of arthropod RTU and 55% of the total reptile RTU; the communal grazing area contained only 37% of the total number of arthropod RTU collected in the study area. 6. Nineteen (73%) of the ant, 18 (69%) of the weevil, 60 (70%) of the spider and 12 (60%) of the grasshopper RTU and 10 (66%) of the reptiles were shared by the three land uses. Six new weevil species and probably several new arachnid species were collected, but all the new weevils were confined to the nature reserve. 7. The communal grazing area differed most from the nature reserve in richness and community composition, followed by the conservatively stocked commercial farm. The historically overgrazed commercial farm was most similar to the nature reserve. 8. The communal grazing area was characterized by xeric-adapted reptiles and predatory arthropods whose ranges are centred in the semi-arid parts of South Africa. In contrast, the nature reserve and commercial farms supported more mesic-adapted reptiles and herbivorous arthropods. 9. Synthesis and applications. The data show how protected areas are key to conserving those species that decrease under heavily grazed and disturbed conditions. However, they also illustrate that diverse land-use mosaics promote gamma diversity in the xeric succulent thicket of South Africa. Conservation policies that include protected space in the wider environment and conserve habitat diversity are likely to both promote regional richness and support scarce species.

ABSTRACT. Bird frugivory on Nectandra megapotamica (Lauraceae) in an area of deciduous seasonal forest in Rio Grande do Sul, Brazil. The importance of Lauraceae fruits has been reported on the diet of several birds, mainly from the Ramphastidae, Cotingidae and Trogonidae families. The objectives of this study were to determine which birds consume the fruits of Nectandra megapotamica (Spreng.) Mez (Lauraceae) in a deciduous seasonal forest and, based on the analysis of some of the qualitative and quantitative dispersal components, infer which birds can act as dispersers of the seeds. The study was carried out at the Campo de Instrução de Santa Maria (CISM) (29º43'S, 53º42'W), in the vicinity of Santa Maria, in Rio Grande do Sul State, Brazil. In a total of 70 hours of focal observation, 726 visits of 21 bird species were registered. The birds considered as potential dispersers of N. megapotamica were Turdus albicollis Vieillot, 1818, T. rufiventris Vieillot, 1818, Pitangus sulphuratus (Linnaeus, 1766) and T. amaurochalinus Cabanis, 1850 among the residents, and Tyrannus savanna Vieillot, 1808 and Myiodynastes maculatus (Müller, 1766) among the migratory ones. Generalist birds seemed to enhance the dispersal of N. megapotamica, since they consumed the entire fruits, realized short visits (shorter than 3 minutes) and presented high frequency of visits which, in turn, is related to a higher rate of fruit removal. Nectandra megapotamica shows features that allow it to be included in the generalist dispersal system, except for the high nutritional level of its seeds. KEYWORDS. Nectandra megapotamica,

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The first undoubted record of the species in the State, at 56° 08' W e 28° 46' S, is given, based on visual observation with slide documentation of two flocks, totalling 236 birds, in may 1991.