The Experts below are selected from a list of 101733 Experts worldwide ranked by ideXlab platform
Jacob Willie - One of the best experts on this subject based on the ideXlab platform.
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the influence of Transect use by local people and reuse of Transects for repeated surveys on nesting in western lowland gorillas gorilla gorilla gorilla and central chimpanzees pan troglodytes troglodytes in southeast cameroon
International Journal of Primatology, 2013Co-Authors: Nikki Tagg, Jacob WillieAbstract:Monitoring populations of endangered species over time is necessary to guide and evaluate conservation efforts. This is particularly important for nonprotected areas that ensure connectivity between protected populations but are prone to uncontrolled hunting pressure. We investigated whether use of Transects by local people and Transect reuse for repeated surveys influence great ape nesting and bias results. We conducted simultaneous marked nest count surveys over 12 mo on established and newly opened Transects in a nonprotected area subject to traditional heavy use by local people and recorded forest composition and signs of human activity. Chimpanzee and gorilla density estimates and encounter rates per kilometer were lower on established Transects than on new ones. A generalized linear model indicated that hunting activity, distance to a regularly used forest trail, and Transect type (old or new) predicted chimpanzee nest abundance, and distance to the trail and Transect type predicted gorilla nest abundance, with no effect of habitat type (percentage suitable habitat) for either species. We, therefore, suggest that the difference in great ape nesting is a result of high levels of hunting by local people on established Transects and forest trails. Our results support the use of repeated line Transect surveys for monitoring great ape populations in many circumstances, although we advocate taking precautions in nonprotected areas, to avoid the bias imposed by use of established Transects for hunting.
Eva Božikova - One of the best experts on this subject based on the ideXlab platform.
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mitochondrial dna in the hybrid zone between mus musculus musculus and mus musculus domesticus a comparison of two Transects
Biological Journal of The Linnean Society, 2005Co-Authors: Miloš Macholán, Katherine C. Teeter, Priscilla K. Tucker, Pavel Munclinger, Eva Božikova, Jaroslav PiálekAbstract:We studied mtDNA introgression across the contact zone between Mus musculus musculus and M. m. domesticus in two independent Transects in the Czech Republic and Bavaria, Germany. A total of 1270 mice from 98 localities in the Czech Transect and 456 mice from 41 localities in the Bavarian Transect were examined for presence or absence of a BamHI restriction site in the mt-Ndl gene. Using this simple mtDNA marker, variants that belonged to the M. m. domesticus lineage (presence of restriction site) could be unequivocally distinguished from those belonging to the M. m. musculus lineage (absence of restriction site). The extent of introgression of mtDNA, three autosomal allozymes and the X chromosome was compared. The introgression of X markers was more limited than was that of the allozymes and mtDNA. In the Czech Transect, the centre for the mtDNA dine was shifted about 3.6 km to the west relative to the X chromosome dine, with asymmetric introgression from M. m. musculus to M. m. domesticus. Interestingly, in the Bavarian Transect, the centre of the mtDNA dine was shifted about 10.9 km to the east relative to the X chromosome dine, with asymmetric introgression from M. m. domesticus to M. m. musculus, opposite in direction to that observed in the Czech Transect.
Collins Scott - One of the best experts on this subject based on the ideXlab platform.
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Grassland Vegetation Line-Intercept Transects at the Sevilleta National Wildlife Refuge, New Mexico (1989 - present)
UNM Digital Repository, 2015Co-Authors: Collins ScottAbstract:In 1989, line-intercept Transects were installed to evaluate temporal and spatial dynamics across vegetation transition zones. Currently, a 400m Transect is sampled at a grassland site (Deep Well) which is dominated by Bouteloua eriopoda (black grama) and, near the southern end of the Transect, B. gracilis (blue grama). A second grassland site (Five Points), dominated by B. eriopoda and, to the south, Larrea tridentata (creosote), is also sampled. Both sites are sampled twice a year, in May/June and September/October, and measurements are taken at a one-centimeter resolution. The biannual sampling protocol detects potential responses in both cool and warm season plants as well as pre- and post-monsoon dynamics. Several Transects have been discontinued and data archived within SEV200
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Grassland Vegetation Line-Intercept Transects at the Sevilleta National Wildlife Refuge, New Mexico (1989 - present)
2015Co-Authors: Collins ScottAbstract:This dataset was originally published on the Long Term Ecological Research (LTER) Network Data Portal, https://portal.lternet.edu, and potentially via other repositories or portals as described. The Digital Object Identifier (DOI) of the source data package is doi:10.6073/pasta/df79b8cd91fb5d3442ee3990506ce89f, and may be accessed at http://dx.doi.org/10.6073/pasta/df79b8cd91fb5d3442ee3990506ce89f. Metadata and files included in this record mirror as closely as possible the source data and documentation, with the provenance metadata and quality report generated by the LTER portal reproduced here as '*-provenance.xml' and *-report.html' files, respectively.In 1989, line-intercept Transects were installed to evaluate temporal and spatial dynamics across vegetation transition zones. Currently, a 400m Transect is sampled at a grassland site (Deep Well) which is dominated by Bouteloua eriopoda (black grama) and, near the southern end of the Transect, B. gracilis (blue grama). A second grassland site (Five Points), dominated by B. eriopoda and, to the south, Larrea tridentata (creosote), is also sampled. Both sites are sampled twice a year, in May/June and September/October, and measurements are taken at a one-centimeter resolution. The biannual sampling protocol detects potential responses in both cool and warm season plants as well as pre- and post-monsoon dynamics. Several Transects have been discontinued and data archived within SEV200
Nikki Tagg - One of the best experts on this subject based on the ideXlab platform.
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the influence of Transect use by local people and reuse of Transects for repeated surveys on nesting in western lowland gorillas gorilla gorilla gorilla and central chimpanzees pan troglodytes troglodytes in southeast cameroon
International Journal of Primatology, 2013Co-Authors: Nikki Tagg, Jacob WillieAbstract:Monitoring populations of endangered species over time is necessary to guide and evaluate conservation efforts. This is particularly important for nonprotected areas that ensure connectivity between protected populations but are prone to uncontrolled hunting pressure. We investigated whether use of Transects by local people and Transect reuse for repeated surveys influence great ape nesting and bias results. We conducted simultaneous marked nest count surveys over 12 mo on established and newly opened Transects in a nonprotected area subject to traditional heavy use by local people and recorded forest composition and signs of human activity. Chimpanzee and gorilla density estimates and encounter rates per kilometer were lower on established Transects than on new ones. A generalized linear model indicated that hunting activity, distance to a regularly used forest trail, and Transect type (old or new) predicted chimpanzee nest abundance, and distance to the trail and Transect type predicted gorilla nest abundance, with no effect of habitat type (percentage suitable habitat) for either species. We, therefore, suggest that the difference in great ape nesting is a result of high levels of hunting by local people on established Transects and forest trails. Our results support the use of repeated line Transect surveys for monitoring great ape populations in many circumstances, although we advocate taking precautions in nonprotected areas, to avoid the bias imposed by use of established Transects for hunting.
Jaroslav Piálek - One of the best experts on this subject based on the ideXlab platform.
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mitochondrial dna in the hybrid zone between mus musculus musculus and mus musculus domesticus a comparison of two Transects
Biological Journal of The Linnean Society, 2005Co-Authors: Miloš Macholán, Katherine C. Teeter, Priscilla K. Tucker, Pavel Munclinger, Eva Božikova, Jaroslav PiálekAbstract:We studied mtDNA introgression across the contact zone between Mus musculus musculus and M. m. domesticus in two independent Transects in the Czech Republic and Bavaria, Germany. A total of 1270 mice from 98 localities in the Czech Transect and 456 mice from 41 localities in the Bavarian Transect were examined for presence or absence of a BamHI restriction site in the mt-Ndl gene. Using this simple mtDNA marker, variants that belonged to the M. m. domesticus lineage (presence of restriction site) could be unequivocally distinguished from those belonging to the M. m. musculus lineage (absence of restriction site). The extent of introgression of mtDNA, three autosomal allozymes and the X chromosome was compared. The introgression of X markers was more limited than was that of the allozymes and mtDNA. In the Czech Transect, the centre for the mtDNA dine was shifted about 3.6 km to the west relative to the X chromosome dine, with asymmetric introgression from M. m. musculus to M. m. domesticus. Interestingly, in the Bavarian Transect, the centre of the mtDNA dine was shifted about 10.9 km to the east relative to the X chromosome dine, with asymmetric introgression from M. m. domesticus to M. m. musculus, opposite in direction to that observed in the Czech Transect.
