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| Peres,Pedro Henrique F.; Polverini,Maxihilian S.; Oliveira,Márcio L.; Duarte,José Maurício B.. |
| ABSTRACT Demographic information is the basis for evaluating and planning conservation strategies for an endangered species. However, in numerous situations there are methodological or financial limitations to obtain such information for some species. The marsh deer, an endangered Neotropical cervid, is a challenging species to obtain biological information. To help achieve such aims, the study evaluated the applicability of camera traps to obtain demographic information on the marsh deer compared to the traditional aerial census method. Fourteen camera traps were installed for three months on the Capão da Cruz floodplain, in state of São Paulo, and ten helicopter flyovers were made along a 13-kilometer trajectory to detect resident marsh deer. In addition... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Aerial survey; Capture-recapture; Distance sampling; Population estimate; Sex ratio. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0073-47212017000100241 |
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| Bauer, Robert; Bonhommeau, Sylvain; Brisset, Blandine; Fromentin, Jean-marc. |
| Conservation and management measures for exploited fish species rely on our ability to monitor variations in population abundance. In the case of the eastern stock of Atlantic bluefin tuna (ABFT), recent changes in management policies have strongly affected the reliability of fishery-dependent indicators due to drastic changes in fishing season/area, fisheries selectivity and strategy. However, fishery-independent indices of abundance are rare for large pelagic fish, and obtaining them is often costly and labor intensive. Here, we show that scientific aerial surveys are an appropriate tool for monitoring juvenile bluefin tuna abundance in the Mediterranean. We present an abundance index based on 62 aerial surveys conducted since 2000, using 2 statistical... |
| Tipo: Text |
Palavras-chave: Thunnus thynnus; Index of abundance; Fishery-independent; Gulf of Lions; Mediterranean Sea; Strip transect; Distance sampling. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00281/39192/45096.pdf |
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| Bouchet, Pj; Miller, Dl; Roberts, Jj; Mannocci, Laura; Harris, Cm; Thomas, L. |
| Forecasting the responses of biodiversity to global change has never been more important. However, many ecologists faced with limited sample sizes and shoestring budgets often resort to extrapolating predictive models beyond the range of their data to support management actions in data‐deficient contexts. This can lead to error‐prone inference that has the potential to misdirect conservation interventions and undermine decision‐making. Despite the perils associated with extrapolation, little guidance exists on the best way to identify it when it occurs, leaving users questioning how much credence they should place in model outputs. To address this, we present dsmextra, a new R package for measuring, summarising, and visualising extrapolation in... |
| Tipo: Text |
Palavras-chave: Cetaceans; Distance sampling; Ecological predictions; Extrapolation; Model transferability; R package; Spatial modelling; Wildlife surveys. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00643/75485/76332.pdf |
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| Andriolo,Artur; Piovezan,Ubiratan; Costa,Mateus J.R. Paranhos da; Torres,Hermógenes A.; Vogliotti,Alexandre; Zerbini,Alexandre N.; Duarte,José M. B.. |
| Balancing power production and environmental conservation can be problematic. The objective of this study was to investigate the abundance of marsh deer in the Paraná River Basin, above the Sergio Motta (Porto Primavera) Dam, before and after the impact of the dam closure. A fixed-wing, flat window aircraft was used to survey study transects. Observations were recorded based on the distance sampling line transect method, assuming that the detection probability decreases with increased distance. The abundance of marsh deer in the survey region prior to flooding was estimated to be 974 individuals (CV = 0.23). The overall abundance dropped from 974 to 444 (CV = 0.26) individuals after flooding, an overall reduction of 54%. This reduction can be attributed to... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Abundance; Anthropogenic impact; Cervids; Distance sampling; Distribution. |
| Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-46702013000600007 |
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| Ferreguetti,Átilla C.; Pereira,Bruno C.; Bergallo,Helena G.. |
| ABSTRACT The spotted paca, Cuniculus paca (Linnaeus, 1766), is a Neotropical, opportunistic, frugivorous caviomorph rodent, that inhabits primarily broadleaf forests. We aimed to provide the first estimates of density of C. paca for the Ilha Grande, an island located in the Atlantic Rain Forest biome of Brazil. Density and population size were estimated using the total number of individuals observed along each trail through the program DISTANCE 7. Our estimates of density and population size reinforces the importance of the Ilha Grande as an important reservoir of the species. Therefore, the results presented herein can be a starting point to support future action plans for the species, making predictions regarding the ecosystem and management and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Abundance; Distance sampling; Ilha Grande State Park; Line-transect. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-46702018000100344 |
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| Ferreguetti,Atilla C.; Oliveira,Amanda B.M. de; Pereira,Bruno C.; Santori,Ricardo T.; Geise,Lena; Bergallo,Helena G.. |
| ABSTRACT Alouatta guariba clamitans Cabrera, 1940 is an endemic species of the Atlantic Forest that occurs from south Bahia, Brazil, extending south to the province of Misiones, Argentina. In Rio de Janeiro state, the species was classified as threatened, indicating that attention is needed for the conservation of this taxon. Additionally, an outbreak of yellow fever spread throughout the southeastern states of Brazil from January 2017 until March 2018 seriously threatening Rio de Janeiro populations of the species. Herein, we aimed to provide the first estimates of A. g. clamitans encounter rate, density, and population size in the Ilha Grande State Park (PEIG), which is part of the Atlantic Forest biome of Brazil. Data were collected in two different... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Distance sampling; Linear transect; Primates; Scan-sampling; Southern brown howler monkey. |
| Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-46702020000100305 |
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| Cremer,Marta J.; Simões-Lopes,Paulo C.. |
| Pontoporia blainvillei (Gervais & d'Orbigny, 1844) is threatened throughout its distribution. The species can be found year-round in the Babitonga bay estuary (26º 02'-26º 28'S and 48º28'-48º50'W), in the north coast of the state of Santa Catarina, Brazil. Boat surveys were conducted in order to evaluate its abundance and density between 2000 and 2003. Sampling was random and stratified, with 46 transects in five sub-areas, comprising a total area of 160 km². Data collection was conducted following the linear transect method with distance sampling. A total of 1174.7 km was scanned and 38 groups were observed. Franciscanas were not uniformly distributed in Babitonga bay. Group size ranged from one to 13 animals (mean ± SD = 5.02 ± 3.62). Model 1... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Concentration area; Distance sampling; Group size. |
| Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-81752008000300003 |
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