8 resultados para Threatened flora

em Biblioteca Digital da Produção Intelectual da Universidade de São Paulo


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Populations of grassland birds are declining in Brazil due to profound alterations to grassland habitats. In this paper, we present recent records and range extensions for 12 threatened or little known Brazilian grassland species: Ocellated Crake Micropygia schomburgkii, Sickle-winged Nightjar Eleothreptus anomalus, Campo Miner Geositta poeciloptera, Rufous-sided Pygmytyrant Euscarthmus rufomarginatus, Sharp-tailed Grass-tyrant Culicivora caudacuta, Cocktailed Tyrant Alectrurus tricolor, Cinereous Warbling-finch Poospiza cinerea, Black-masked Finch Coryphaspiza melanotis, Tawny-bellied Seedeater Sporophila hypoxantha, Marsh Seedeater S. palustris, Chestnut Seedeater S. cinnamomea and Black-bellied Seedeater S. melanogaster. We also comment on the biogeography and conservation of these species.

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Brycon nattereri (Ostariophysi: Characiformes: Characidae), a threatened South American freshwater fish, occurs in the Parana, Tocantins and Sao Francisco river basins in central Brazil. It is a middle-sized (up to 50 cm SL), omnivorous species, which occurs in swift, clear-water rivers with well-preserved riparian vegetation. Main threats to the species are water pollution, dam building, and deforestation.

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A rich and well-preserved Glossopteris-dominated plant fossil assemblage is described from the Barakar Formation of the Makardhokra and Umrer open-cast projects, Umrer Coalfield, Nagpur District, Wardha Basin, Maharashtra, India. The assemblage includes equisetalean axes, cordaitalean leaves (Noeggerathiopsis hislopii), Gangamopteris clarkeana and diverse Glossopteris leaves and a fertile organ assigned to Scutum sp. cf. S. leslii. The flora, although similar to that of the Barakar Formation of the Damodar Basin complex (the reference basin system with respect to the qualitative and quantitative distribution of Indian Permian plant taxa), exhibits unique characteristics and is Artinskian to Kungurian in age. Besides supplementing knowledge of the broader Wardha Basin flora, this is the first systematic documentation of the Glossopteris flora from the Barakar Formation of this basin.

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We describe a new species of Bothrops from Vitoria Island, off the coast of Sao Paulo, southeastern Brazil. The new species differs from the mainland coastal populations of B. jararaca mostly in its smaller and stouter body, number and form of scales, and hemipenial morphology. From B. insularis and B. alcatraz, both related species endemic to islands in southeastern Brazil, B. otavioi sp. nov. differs mainly in its body form and number of scales. The new species has the twist common mitochondrial haplotype for mainland populations of B. jararaca, which is also found in B. alcatraz. A mitochondrial genealogy (gene tree) shows the new species nested within the northern clade of B. jararaca. This genealogical pattern can be explained by a recent speciation event for B. otavioi sp. nov. The isolation of insular species of Bothrops from continental ancestor populations are probably related to the same vicariant process, the oscillations of sea level during the Pleistocene. The new species feeds on small hylid frogs, and attains sexual maturity at 388 mm snout-vent length (SVL; males) and 692 mm SVL (females). Bothrops facial sp. nov. is endemic to Vitoria Island, and should be listed as critically endangered because it is known from only a single area (an island), its geographic range covers less than 100 km(2), and there is a projected continuing decline in the quality of its habitat because of increasing human settlement.

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The pressures for land use change have led to an increasing isolation of habitat remnants throughout the world. The goal of this study was to estimate the population size and density of some endemic and threatened species in a nature reserve in the Cerrado biome. One hundred and thirty four point transects were undertaken at the Estacao Ecologica de Itirapina (EEI), one of the last natural grassland savannah remnants in Sao Paulo state, in the south-east of Brazil between September and December 2006 and densities estimated for seven species (four endemic to the Cerrado, one near-endemic and two grassland specialists). Neither species reached the minimum viable population size of 500-5000 individuals. Four species, White-banded Tanager, White-rumped Tanager, Black-throated Saltator and Sharp-tailed Tyrant have populations ranging from 112 to 248 individuals, while the other species have a low population (< 60 individuals). The mean densities of Sharp-tailed Tyrant and Cock-tailed Tyrant in the EEI grassland showed similar values to those observed in larger areas of the Cerrado, which may indicate that the EEL grassland area is well conserved. In spite of the restricted size of the EEI, small areas can maintain some endemic and threatened bird populations, thus contributing to local biodiversity and the ecological processes in the region. The capacity of fragments of Cerrado (similar to 2,000 ha) to maintain populations of endemic and threatened bird species is unlikely to be effective in the long term.

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Activity and behavior patterns are important components of a given species ecological strategy, as they have profound implications for its survival and reproduction. Here, we studied the activities, movements and secretive behavior of the thin-spined porcupine Chaetomys subspinosus (Rodentia: Erethizontidae), a threatened arboreal folivore in the Brazilian Atlantic rainforest. We aimed to ascertain the behavioral strategies used by this species as well as its responses to seasonal and daily climatic changes. Four radio-collared individuals were followed continuously for 72-h in the summer and winter, as well as during 146 half-night sessions conducted from April 2005 to September 2006 in forest remnants in southern Bahia. The thin-spined porcupines were nocturnally active (17:30-05:40 h), with peaks in activity and movement from 19:00 to 20:00 h and 03:00 to 04:00 h. Animals followed a circadian rhythm of activity during both the summer and winter. During the diel cycle, porcupines spent 74% of their time resting, 14% feeding, 11% traveling and 2% performing other activities. Distance traveled during the diel cycle averaged 277.5 +/- 117.9 m sd. The mean movement rate during the night was 21.6 +/- 30.1 m/h sd. No significant changes in activity budget or daily distance traveled were observed between seasons, most likely in response to the low fluctuations in climatic conditions and food availability throughout the year in the study region. However, rainfall reduced the time that the animals spent on feeding activities and explained day-to-day differences in activity budgets. We also provide details about intraspecific interactions and defecation behavior. Our observations confirmed that thin-spined porcupines, similar to other folivorous species, present low activity levels and short daily movements, and have adopted various cryptic habits, such as nocturnality, a solitary lifestyle, the tendency to leave offspring alone most of the time and defecation in concealed latrines.

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Joseph Barbosa de Sáa (? – 1775), mais conhecido por seus escritos sobre a história do estado do Mato Grosso, Brasil, completou em 1769 um volumoso (408 fólios) e erudito manuscrito, intitulado “Dialogos geograficos, coronologicos, polliticos e naturais”, que nunca foi publicado na íntegra. Esse manuscrito está depositado na Biblioteca Pública do Porto (manuscrito no. 235), em Portugal. Dez capítulos desse manuscrito tratam dos produtos naturais do Brasil (acima de mil, quase a metade sendo animais), observados por Sáa ao longo da costa do Rio de Janeiro, em São Paulo, sul de Goiás e especialmente no Mato Grosso, sendo a primeira monografia sobre a história natural deste último estado. Esses capítulos são aqui transcritos e comentados.

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Myrtaceae é uma das famílias mais representativas da flora brasileira, fato que não tem sido acompanhado por um número expressivo de trabalhos taxonômicos. O presente estudo teve como objetivo realizar o tratamento taxonômico para a família na Serra do Ouro Branco, o ponto mais ao sul da Serra do Espinhaço. Foram registrados 10 gêneros e 24 espécies para a região: Accara (1 sp.), Blepharocalyx (1 sp.), Calyptranthes (2 spp.), Campomanesia (2 spp.), Eugenia (2 spp.), Marlierea (2 spp.), Myrceugenia (2 spp.), Myrcia (10 spp.), Psidium (1 sp.), Siphoneugena (1 sp.). São apresentados chaves de identificação, descrições e comentários sobre gêneros e espécies.