GARDNER, S.L.; RAUSCH, R.L.; CAMACHO, O.C.J. 1988. Echinococcus vogelu Rausch and Bernstein, 1972, from the paca, Cuniculus paca L. (Rodentia: Dasyproctidae), in the Departamento de Santa Cruz, Bolivia. Journal of Parasitology 74 (3):399-402.
Abstract. Among approximately 2,000 mammals examined for helminths in various regions of Bolivia during 1983-1987, cysts of Echinococcus vogeli Rausch and Bernstein, 1972, were found in a single paca, Cuniculus paca L., collected at La Laguna, Departamento de Santa Cruz (lat. 16'36''W; long. 62'42''S). This record, the first from Bolivia, represents a considerable extension of the known geographic range of this species in South America. Upon analysis of the morphologic characteristics of the protoscoleces derived from the cysts, the sizes of rostellar hooks from the material from the paca were found to be well within the ranges reported in previous studies. Statistical analysis of frequency distributions of hook characteristics revealed some deviations from normality. These results indicate that parametric statistics should be applied with caution in analyses of interand intraspecific variation of morphologic characteristics of hooks of metacestodes of the genus Echinococcus.
Mostrando postagens com marcador Neoartic region. Mostrar todas as postagens
Mostrando postagens com marcador Neoartic region. Mostrar todas as postagens
sábado, 17 de janeiro de 2015
sábado, 18 de outubro de 2014
Camera-trap study of ocelot and other secretive mammals in the northern Pantanal
TROLLE, M.; KÉRY, M. 2005. Camera-trap study of ocelot and other secretive mammals in the northern Pantanal. Mammalia 69:3-4.
Abstract. Reliable information on abundance of the ocelot (Leopardus pardalis) is scarce. We conducted the first camera-trap study in the northern part of the Pantanal wetlands of Brazil, one of the wildlife hotspots of South America. Using capture-recapture analysis, we estimated a density of 0.112 independent individuals per km² (SE 0.069). We list other mammals recorded with camera traps and show that camera-trap placement on roads or on trails has striking effects on camera-trapping rates.
Abstract. Reliable information on abundance of the ocelot (Leopardus pardalis) is scarce. We conducted the first camera-trap study in the northern part of the Pantanal wetlands of Brazil, one of the wildlife hotspots of South America. Using capture-recapture analysis, we estimated a density of 0.112 independent individuals per km² (SE 0.069). We list other mammals recorded with camera traps and show that camera-trap placement on roads or on trails has striking effects on camera-trapping rates.
sábado, 1 de fevereiro de 2014
Efficiency of box-traps and leg-hold traps with several bait types for capturing small carnivores (Mammalia) in a disturbed area of Southeastern Brazil
MICHALSKI, F.; CRAWSHAW JR., P.G.; OLIVEIRA, T.G.; FABIÁN, M.E. 2007. Efficiency of box-traps and leg-hold traps with several bait types for capturing small carnivores (Mammalia) in a disturbed area of Southeastern Brazil. Revista de Biología Tropical 55(1):315-320.
Abstract. Capturing small carnivores is often necessary for obtaining key ecological data. We compared the efficiency of box and leg-hold traps, using live and dead bait, to capture six carnivore species (Herpailurus yagouaroundi (É. Geoffroyi, 1803), Leopardus tigrinus (Schreber, 1775), Nasua nasua (Linnaeus, 1766), Cerdocyon thous (Linnaeus, 1766), Eira barbara (Linnaeus, 1758), and Galictis cuja (Molina, 1782)). The use of leg-hold traps significantly increased the capture rate of carnivores (5.77%) and non-target species (non-carnivores, 11.54%). Dead bait significantly attracted more non-carnivores than carnivores and live bait was more efficient for capturing carnivores (2.56%) than non-carnivores (0.77%). Both box and leg-hold traps caused some minor injuries (swelling and claw loss). We provide recommendations for the ethical use of these trap and bait types.
Abstract. Capturing small carnivores is often necessary for obtaining key ecological data. We compared the efficiency of box and leg-hold traps, using live and dead bait, to capture six carnivore species (Herpailurus yagouaroundi (É. Geoffroyi, 1803), Leopardus tigrinus (Schreber, 1775), Nasua nasua (Linnaeus, 1766), Cerdocyon thous (Linnaeus, 1766), Eira barbara (Linnaeus, 1758), and Galictis cuja (Molina, 1782)). The use of leg-hold traps significantly increased the capture rate of carnivores (5.77%) and non-target species (non-carnivores, 11.54%). Dead bait significantly attracted more non-carnivores than carnivores and live bait was more efficient for capturing carnivores (2.56%) than non-carnivores (0.77%). Both box and leg-hold traps caused some minor injuries (swelling and claw loss). We provide recommendations for the ethical use of these trap and bait types.
sábado, 7 de dezembro de 2013
Use of vertical space by small mammals in gallery forest and woodland savannah in south-western Brazil
HANNIBAL W.; CÁCERES NC. 2010. Use of vertical space by small mammals in gallery forest and woodland savannah in south-western Brazil. Mammalia 74: 247-255. doi: 10.1515/MAMM.2010.007
Abstract. We examined the community composition and abundance of small mammals in the vertical strata of gallery forests and woodland savannahs in south-western Brazil. Captures were carried out during the winter and summer months of 2006/2007. Traps were set in three transect lines per habitat, with 10 capture stations on each line. Each station had three traps: on the ground, in the understorey (2–3 m in height), and in the canopy (8–10 m) in each physiognomy. With an effort of 3600 trap-nights, 11 species of small mammals were captured, which were distributed differently regarding the forest physiognomies and utilisation of vertical strata. The species showed a high degree of habitat segregation in the two physiognomies, with only the climbing-rat Rhipidomys macrurus found in both habitats. The correspondence analysis revealed that Caluromys philander occurred mostly in the canopy; Cryptonanus agricolai, Marmosa murina, and Oecomys bicolor in the understorey; and Gracilinanus agilis and Nectomys rattus on the ground. The utilisation of traps in different strata increased species richness in the Cerrado biome, showing that the small-mammal community is distributed along the vertical complexity of the forest and even in different physiognomies, enabling more species to coexist.
Abstract. We examined the community composition and abundance of small mammals in the vertical strata of gallery forests and woodland savannahs in south-western Brazil. Captures were carried out during the winter and summer months of 2006/2007. Traps were set in three transect lines per habitat, with 10 capture stations on each line. Each station had three traps: on the ground, in the understorey (2–3 m in height), and in the canopy (8–10 m) in each physiognomy. With an effort of 3600 trap-nights, 11 species of small mammals were captured, which were distributed differently regarding the forest physiognomies and utilisation of vertical strata. The species showed a high degree of habitat segregation in the two physiognomies, with only the climbing-rat Rhipidomys macrurus found in both habitats. The correspondence analysis revealed that Caluromys philander occurred mostly in the canopy; Cryptonanus agricolai, Marmosa murina, and Oecomys bicolor in the understorey; and Gracilinanus agilis and Nectomys rattus on the ground. The utilisation of traps in different strata increased species richness in the Cerrado biome, showing that the small-mammal community is distributed along the vertical complexity of the forest and even in different physiognomies, enabling more species to coexist.
sábado, 21 de setembro de 2013
Trend of the Yellowstone grizzly bear population
EBERHARDT, L.L.; BREIWICK, J.M. 2010. Trend of the Yellowstone grizzly bear population. International Journal of Ecology, v. 2010, Article ID 924197, 5 pages. doi: 10.1155/2010/924197.
Abstract. Yellowstone’s grizzlies (Ursus arctos) have been studied for more than 40 years. Radiotelemetry has been used to obtain estimates of the rate of increase of the population, with results reported by Schwartz et al. (2006). Counts of females with cubs-of-the-year “unduplicated” also provide an index of abundance and are the primary subject of this report. An exponential model was fitted to n = 24 such counts, using nonlinear leastsquares. Estimates of the rate of increase, r, were about 0.053. 95% confidence intervals, were obtained by several different methods, and all had lower limits substantially above zero, indicating that the population has been increasing steadily, in contrast to the results of Schwartz et al. (2006), which could not exclude a decreasing population. The grizzly data have been repeatedly mis-used in current literature for reasons explained here.
Abstract. Yellowstone’s grizzlies (Ursus arctos) have been studied for more than 40 years. Radiotelemetry has been used to obtain estimates of the rate of increase of the population, with results reported by Schwartz et al. (2006). Counts of females with cubs-of-the-year “unduplicated” also provide an index of abundance and are the primary subject of this report. An exponential model was fitted to n = 24 such counts, using nonlinear leastsquares. Estimates of the rate of increase, r, were about 0.053. 95% confidence intervals, were obtained by several different methods, and all had lower limits substantially above zero, indicating that the population has been increasing steadily, in contrast to the results of Schwartz et al. (2006), which could not exclude a decreasing population. The grizzly data have been repeatedly mis-used in current literature for reasons explained here.
sábado, 31 de agosto de 2013
Interactions between short-beaked common dolphin (Delphinus delphis) and the winter pelagic pair-trawl fishery off Southwest England (UK)
BOER, M.N.; SAULINO, J.T.; LEOPOLD, M.F.; RIJNDERS, P.J.H.; SIMMONDS, M.P. 2012. Interactions between short-beaked common dolphin (Delphinus delphis) and the winter pelagic pair-trawl fishery off Southwest England (UK). International Journal of Biodiversity and Conservation 4(13):481-499. doi: 10.5897/IJBC12.016
Abstract. During offshore and onshore studies (2004 to 2009), the interactions between pair-trawls and shortbeaked common dolphins (Delphinus delphis) were studied to better understand the impact of bycatch. A ‘hotspot’ area where pair-trawls overlapped with high dolphin abundance was identified. We made comparisons between boat-based data collected in absence and presence of pair-trawlers. The relative abundance and group-size of dolphins was significantly higher in the presence of pair-trawlers. Dolphins were observed associating with towing and hauling procedures. Significantly, more carcasses occurred in areas with hauling-activity than those without. Body-temperatures obtained from carcasses found near operating pair-trawlers indicated that bycatch mostly occurred at night. During necropsy studies, difficulties were encountered in identifying the fishing-gears responsible. Strandings data highlighted that the number of dead stranded dolphins was probably much higher than previously reported and there was a significant difference in the age and gender-composition of carcasses. Mature/sub-adult males appeared at greater risk from entanglement in pair-trawls offshore, whilst females with young appeared more vulnerable to inshore gillnets. Our findings show that the overlap between pelagic fisheries and the common dolphin hotspot is causing direct mortality through bycatch and, together with recent range-shifts, may have contributed to a localised decline of this species in this winter hotspot since 2007.
Abstract. During offshore and onshore studies (2004 to 2009), the interactions between pair-trawls and shortbeaked common dolphins (Delphinus delphis) were studied to better understand the impact of bycatch. A ‘hotspot’ area where pair-trawls overlapped with high dolphin abundance was identified. We made comparisons between boat-based data collected in absence and presence of pair-trawlers. The relative abundance and group-size of dolphins was significantly higher in the presence of pair-trawlers. Dolphins were observed associating with towing and hauling procedures. Significantly, more carcasses occurred in areas with hauling-activity than those without. Body-temperatures obtained from carcasses found near operating pair-trawlers indicated that bycatch mostly occurred at night. During necropsy studies, difficulties were encountered in identifying the fishing-gears responsible. Strandings data highlighted that the number of dead stranded dolphins was probably much higher than previously reported and there was a significant difference in the age and gender-composition of carcasses. Mature/sub-adult males appeared at greater risk from entanglement in pair-trawls offshore, whilst females with young appeared more vulnerable to inshore gillnets. Our findings show that the overlap between pelagic fisheries and the common dolphin hotspot is causing direct mortality through bycatch and, together with recent range-shifts, may have contributed to a localised decline of this species in this winter hotspot since 2007.
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