Habitat split and the global decline of amphibians

The worldwide decline in amphibians has been attributed to several causes, especially habitat loss and disease. We identified a further factor, namely habitat split- defined as human- induced disconnection between habitats used by different life history stages of a species- which forces forest- associated amphibians with aquatic larvae to make risky breeding migrations between suitable aquatic and terrestrial habitats. In the Brazilian Atlantic Forest, we found that habitat split negatively affects the richness of species with aquatic larvae but not the richness of species with terrestrial development ( the latter can complete their life cycle inside forest remnants). This mechanism helps to explain why species with aquatic larvae have the highest incidence of population decline. These findings reinforce the need for the conservation and restoration of riparian vegetation.

Habitat of juvenile Caribbean reef sharks, Carcharhinus perezi, at two oceanic insular marine protected areas in the southwestern Atlantic Ocean: Fernando de Noronha Archipelago and Atol das Rocas, Brazil

Habitat of juvenile Caribbean reef sharks, Carcharhinus perezi (Carcharhinidae), was identified using fishing surveys and capture of immature specimens at two Brazilian insular sites in the southwestern Atlantic Ocean, Fernando de Noronha Archipelago and Atol das Rocas. Standardized sampling at Fernando de Noronha indicated that parturition occurred from February to April and that a wide depth-range (at least 5-30 m) along the insular shelf was used by immature sharks throughout the year. The catch-per-unit effort of C. perezi was significantly higher inside than outside a marine protected area at this location, suggesting that these sharks are more common in pans of the reef least disturbed by human activities. More limited sampling at Atol das Rocas suggested that juvenile C. perezi occurred at similar depths and utilized similar substrate as sharks at Fernando de Noronha. These findings suggest that successful conservation and management of this economically important, protected species will need to include conservation of habitat around insular reef systems. (c) 2006 Elsevier B.V. All rights reserved.

Composition and structure of fish assemblage from Passa Cinco stream, Corumbataí river sub-basin, SP, Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Daily activity and microhabitat use of sympatric lizards from Serra do Cipó, southeastern Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Geographical variation in genetic structure of an Atlantic Coastal Forest frog reveals regional differences in habitat stability

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Habitat Split as a Cause of Local Population Declines of Amphibians with Aquatic Larvae

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Niche occupancy and the relative role of micro-habitat and diet in resource partitioning among pond dwelling tadpoles.

We determined microhabitat and diet niche for tadpoles from two ponds in an agricultural landscape. Additionally, we verified the intraspecific variation in resource use, and if diet and microhabitat use were correlated. Tadpoles found in the two ponds differed in microhabitat use, because in the larger pond they explored deeper places far from the margin. There were three groups with high microhabitat niche overlap. In both ponds, plant cover was the best descriptor to explain interspecific variation in microhabitat use. Tadpoles of all species ingested mainly Bacillariophyceae and Trachellomonas however the diet differed intraspecifically in the species from the two ponds. Ten items in the temporary pond and 15 items in the permanent one were ingested by all species; however, the relative abundance of each item differed. Diet similarity was not correlated to similarity in microhabitat use. In this study, diet was as important as microhabitat use to explain resource partitioning.

The golden lancehead Bothrops insularis (Serpentes: Viperidae) relies on two seasonally plentiful bird species visiting its island habitat

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

The Q-D algorithm for transforming series expansions into a corresponding continued fraction: an extension to cope with zero coefficients

An algorithm for deriving a continued fraction that corresponds to two series expansions simultaneously, when there are zero coefficients in one or both series, is given. It is based on using the Q-D algorithm to derive the corresponding fraction for two related series, and then transforming it into the required continued fraction. Two examples are given. (C) 2003 Elsevier B.V. All rights reserved.

An Extension of Craig's Family of Lattices

Let p be a prime, and let zeta(p) be a primitive p-th root of unity. The lattices in Craig's family are (p - 1)-dimensional and are geometrical representations of the integral Z[zeta(p)]-ideals < 1 - zeta(p)>(i), where i is a positive integer. This lattice construction technique is a powerful one. Indeed, in dimensions p - 1 where 149 <= p <= 3001, Craig's lattices are the densest packings known. Motivated by this, we construct (p - 1)(q - 1)-dimensional lattices from the integral Z[zeta(pq)]-ideals < 1 - zeta(p)>(i) < 1 - zeta(q)>(j), where p and q are distinct primes and i and fare positive integers. In terms of sphere-packing density, the new lattices and those in Craig's family have the same asymptotic behavior. In conclusion, Craig's family is greatly extended while preserving its sphere-packing properties.

Effects of physical habitat degradation on the stream fish assemblage structure in a pasture region

We compared the fish assemblage structure from streams with different intensities of physical habitat degradation and chemical water pollution by domestic sewage in southeastern Brazil. Eight streams (R1-R8) showing less disturbed or more disturbed conditions of chemical water quality and of physical habitat quality were selected. Cumulative abundance and biomass, combined in ABC plots, revealed (i) biomass curves above the abundance curves, represented by the streams R1-R2 (water and habitat less disturbed) and R5-R6 (water more disturbed and habitat less disturbed), and (ii) biomass curves below the abundance curves, represented by the streams R3-R4 (water less disturbed and habitat more disturbed) and R7-R8 (water and habitat more disturbed). The quantitative structure of the ichthyofauna showed significant correspondence with physical habitat condition but not with chemical water quality. The most significant species to cause the dissimilarity between less disturbed and more disturbed physical habitats was the exotic Poecilia reticulata. Such results indicate that in the focused region-with little influence of industrial pollution, noncritical domestic sewage discharge, and soil predominantly used for pasture-streams with high physical habitat integrity possess a differently structured ichthyofauna than streams with relatively low physical habitat integrity, reinforcing the importance of the physical habitat quality and riparian conservation along these water courses, warranting the conservation of these systems. Indeed, our results also reinforce the importance of including biotic descriptors, particularly of the ichthyo-fauna, in water-monitoring programs designed to reveal signs of human interference.

Range extension of the Peale's Free-tailed Bat Nyctinomops aurispinosus (Molossidae) in Brazil

Há uma grande lacuna no conhecimento da biologia e corologia de Nyctinomops aurispinosus. Nesta comunicação, nós apresentamos o registro mais austral deste molossídeo, realizado na cidade de Curitiba (25° 25' S e 49° 15' W, 920 m), estado do Paraná, Brasil, e sumarizamos a distribuição geográfica conhecida para a espécie na América do Sul.

Habitat simplification affects nuclear-follower foraging association among stream fishes

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Habitat selection and potential antiherbivore effects of Peucetia flava (Oxyopidae) on Solanum thomasiifolium (Solanaceae)

Several spider species use plants as shelter and foraging sites, but the relationships among these organisms are still poorly known. Lynx spiders of the genus Peucetia do not build webs, and many species live strictly in plants bearing glandular trichomes. Peucetia flava Keyserling 1877 inhabits Solanum thomasifolium in southeastern Brazil and usually preys on herbivores and other small insects adhered to the glandular trichomes of its host plant. To evaluate the potential anti-herbivore protection. of this spider species for S. thomasifolium, we glued termites used as herbivore models oil trichomes of S. thomasifolium and on neighboring plants lacking glandular trichomes. leaf miner damage and spider density were recorded for S. thomasifolium plants in July 1997. There was a positive relationship between plant size and spider density. The removal or termites in S. thomasifolium by P. flava was higher than ill plants without glandular trichomes. The leaf miner damage was negatively related to spider density. Our results Suggest that P. flava may be all important plant bodyguard in the defense of S. thomasifolium from its natural herbivores.