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Trindade M.E.J.,Institute Desenvolvimento Sustentavel Mamiraua IDSM | Peressin A.,Federal University of Sao Carlos | Cetra M.,Federal University of Sao Carlos | Juca-Chagas R.,State University of Southwest Bahia
Acta Limnologica Brasiliensia | Year: 2013

Aim: in this study we present data from the diet of Astyanax vermilion which were used as a tool to compare two sites of streams with different vegetation cover in Ribeirão Limoeiro, Cachoeira River Basin, BA. Methods: Four samples were taken (March, June, September and December) using electrofishing as the collection method in two contiguous sites of the headwaters: stretch without riparian vegetation and with riparian vegetation. Results: The qualitative composition of the diet was analyzed by the method of frequency of occurrence. The allochthonous resources of vegetal origin made up the bulk of the diet in the stretch without riparian vegetation with a frequency of occurrence of 64%. In the section with riparian vegetation allochthonous resources of animal origin made up the bulk of the diet with a frequency of 62%, which emphasizes the importance of food items from the surrounding environment. The mean Shannon diversity index, calculated from the frequency of occurrence of food items was significantly different (p = 0.04) when comparing reach deforested (H'= 1.44) with reach forested (H'= 1.80). The average weight of stomachs in the deforested reach (WSD = 0.18g) was significantly higher than that of the forested reach (WSF = 0.14g). Conclusions: in the stretch with riparian vegetation, the food diversity was greater and the fish that are in the riparian stretch do not need as much food to satisfy their physiological needs. These results underscore the importance of the type of riparian vegetation as a food source for fish. Source

Alves M.D.D.O.,Federal University of Pernambuco | Schwamborn R.,Federal University of Pernambuco | Borges J.C.G.,Fundacao Mamiferos Aquaticos FMA | Borges J.C.G.,Federal Rural University of Pernambuco | And 4 more authors.
Biological Conservation | Year: 2013

The objective of the present study was to analyze the distribution of manatees, dolphins and sea turtles off northeastern Brazil through aerial surveys, relating them to specific habitats and human activities, with emphasis on marine protected areas (MPAs). Surveys were conducted between January and April 2010 at 150m altitude and 140kmh-1, using two independent observers. Strip transects were flown in a zigzag pattern. Transects covered 4026km in more than 27 flight hours. A total of 36 sightings of manatees (Trichechus manatus manatus, 41 individuals), 28 of dolphins (Delphinidae, 78 individuals, including 10 Sotalia guianensis) and 256 of sea turtles (Cheloniidae, 286 individuals) were recorded. Manatees and sea turtles displayed solitary habits, while dolphins were commonly seen in groups. Manatees were positively correlated with sea turtles, probably due to their preference for sheltered shallow habitats with favorable conditions for foraging and resting. Furthermore, manatees showed a positive relationship with mangrove estuaries, and medium-sized coastal cities probably due to the intense urban development in many estuarine areas. Manatees and sea turtles were also positively correlated with boats, showing a severe threat for these species. Density of manatees was significantly higher within MPAs with preserved mangrove estuaries than in non-protected areas, while dolphins and sea turtles were observed in high densities MPAs with coral reefs. The elevated density of these organisms shows the vital importance of protecting and adequately managing unique ecosystems to ensure a sustainable future for the populations of severely threatened species. © 2013 Elsevier Ltd. Source

Bernardon B.,Federal University of Mato Grosso | Bernardon B.,Institute Desenvolvimento Sustentavel Mamiraua IDSM | De Nobrega P.F.A.,Federal University of Mato Grosso | De Pinho J.B.,Federal University of Mato Grosso
Revista Brasileira de Ornitologia | Year: 2014

Economic activities, such as extensive cattle ranching, may seriously threaten the types of forest most important to the Mato Grosso Antbird Cercomacra melanaria, and information on reproductive biology is essential for defining sound conservation and management strategies for the species. Here, we report on the reproductive biology of this species in the Brazilian Pantanal, focusing on attributes such as incubation and nestling periods, as well as characteristics of parental care. The hypothesis that nest occurrence is associated with canopy opening was also tested. Average nest height was 0.98 m; mean nest construction and egg incubation periods were 12.2 and 14 days, respectively; average nestling period was 9.4 days. Both males and females participated in nest construction, egg incubation, and feeding of nestlings. The canopy was consistently more open away from the nests (18.74%) than at nest sites (10.10%; p < 0.0001), indicating that C. melanaria selects nest sites with dense vegetation. © 2015 Sociedade Brasileira de Ornitologia. All rights reserved. Source

Villamarin F.,National Institute of Amazonian Research | Marioni B.,Instituto Piagacu IPI | Thorbjarnarson J.B.,Wildlife Conservation Society | Nelson B.W.,National Institute of Amazonian Research | And 2 more authors.
Biological Conservation | Year: 2011

Management of crocodilians is often based on source-sink dynamics, protecting breeding habitat and concentrating hunting in other areas. Nest distributions shed light on habitat use by breeding populations, which might be used as a basis for monitoring and management. The heterogeneous spatial distribution of Melanosuchus niger and Caiman crocodilus in Amazonia has been suggested to reflect past hunting pressure, often underestimating the natural ecological peculiarities of these species. Ground nest surveys combined with satellite imagery allowed us to evaluate whether nest-site use by M. niger and C. crocodilus reflects environmental constraints or is a result of hunting pressure. Our results indicate that there is little evidence that hunting pressure shapes nest-site use of these species in our study areas. M. niger nests mainly on the shores of stable, temporally impounded floodplain lakes isolated from the early stages of the annual rising water of main rivers. This behavior facilitates the identification of suitable nesting sites using moderate-resolution remote-sensing tools and should guide monitoring efforts and the protection of these areas. In contrast, C. crocodilus is a generalist species, able to nest hundreds of meters inside the forest far from permanent water. This makes the occurrence and distribution of nesting-sites unpredictable using Landsat images. Although nests of this species can be found around lakes where nests of M. niger also occur, the protection of these sites might help to preserve only a small portion of C. crocodilus nesting females. Thus, conservation strategies for C. crocodilus should probably be based on different approaches. © 2010 Elsevier Ltd. Source

Freitas M.A.B.,Museu Paraense Emilio Goeldi | Vieira I.C.G.,Museu Paraense Emilio Goeldi | Albernaz A.L.K.M.,Museu Paraense Emilio Goeldi | Magalhaes J.L.L.,Institute Desenvolvimento Sustentavel Mamiraua IDSM | Lees A.C.,Museu Paraense Emilio Goeldi
Forest Ecology and Management | Year: 2015

Enrichment planting of açaí palms (Euterpe oleracea Mart.) has intensified in Amazonian floodplain forests following increases in both domestic and international demand for the açaí palm fruit, now marketed as a 'superfood'. The consequences of this expansion for regional biodiversity are poorly understood and herein we aim to evaluate how variation in açaí management intensity in várzea forests influences forest floristic composition and structure. We established 24 (10 × 100. m) sampling plots in eastern Amazonian forests managed for açaí production and 12 sample plots in unmanaged floodplain forests. We explored variation in community structure (richness, diversity and dominance) mediated by açaí density and habitat characteristics. We measured and identified 3168 trees belonging to 43 families, 119 genera, and 169 species. The current exploitation model practiced by Amazonian riverine communities, maintaining a mean density of 200. stem/ha, led to a loss of over 50% of tree species diversity and a 63% reduction in the number of pioneer species. This translated into a homogenization of the floristic community favoring species of economic interest. We underscore the need for multi-taxon studies to support management plans for economic-ecological zoning in Amazonian várzea forests managed for açaí to prevent broad-scale cryptic biodiversity loss. © 2015 Elsevier B.V. Source

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