Movement of small mammals across divided highways with vegetated medians

2011 ◽  
Vol 89 (12) ◽  
pp. 1214-1222 ◽  
Author(s):  
Ashley A.D. McLaren ◽  
Lenore Fahrig ◽  
Nigel Waltho
Keyword(s):  
Small Mammals ◽  
Small Mammal ◽  
Vegetation Cover ◽  
Forest Cover ◽  
Vegetation Type ◽  
Barrier Effect ◽  
Cover Type ◽  
Study Sites ◽  
Median Width ◽  
Initial Capture

Previous studies suggest the gap in forest cover generated by roads contributes to the barrier effect of roads on movement of forest-dwelling small mammals. However, it is not known if vegetated medians of divided highways affect movement of small mammals by reducing the effective highway width. The purpose of our study was to determine whether the type of vegetation cover in the median (treed or grassy) or median width affects small-mammal crossings of divided highways. At 11 study sites varying in median cover type and width, we live-trapped small mammals next to one side of the highway and translocated them to the opposite side of the highway using a standardized translocation distance. In total, 24% of translocated individuals were recaptured on the side of the highway of initial capture, i.e., they had moved across the entire highway. This was significantly lower than what would have been expected in the absence of the highway (58%). The overall probability of recapturing a translocated individual was not significantly related to median cover type or width. Our results suggest that efforts to mitigate the barrier effect of highways on small mammals cannot be accomplished by altering median vegetation type and width.

The long-term effects of logging for woodchips on small mammal populations

2009 ◽  
Vol 36 (8) ◽  
pp. 691 ◽  
Author(s):  
Daniel Lunney ◽  
Alison Matthews ◽  
Peggy Eby ◽  
Angela M. Penn
Keyword(s):  
Small Mammals ◽  
Small Mammal ◽  
Sustainable Forest Management ◽  
Long Term Effects ◽  
Mammal Species ◽  
North West ◽  
South Wales ◽  
Study Sites ◽  
Species Specific

Context. Long-term studies are internationally recognised as an essential component of achieving ecologically sustainable forest management with respect to fauna. Aims. This study aimed to assess longer-term responses of small mammals to logging by returning in 1998 to our 1980–83 study sites in south-eastern New South Wales, Australia. Methods. Three age-classes of forest were surveyed: unlogged; 18–19-year-old regrowth; and 26–34-year-old regrowth. Key results. Rattus fuscipes remained affected by logging, and there were significantly fewer R. fuscipes males in logged, north-west-facing sites than at other sites, although the effect was less pronounced in 1998 than in 1980–83. Antechinus agilis females were significantly less numerous in south-east-facing, unlogged forest. This was not expected from the 1980–83 results. Antechinus swainsonii, which had disappeared following a fire in 1980, had returned to the forest by 1998. A. swainsonii females showed a significant preference for south-east-facing slopes and this relationship was consistent between logged and unlogged forest. No members of Mus musculus or Sminthopsis leucopus, which were present in 1980–83, were caught in 1998. Conclusions. As in the 1980s study, the responses of small mammal species to logging history were varied and species specific. Implications. In our study area, we predict that sustained logging for woodchips will continue to deplete its populations of small mammals. This adds to the case for a more robust and sustained approach to researching and managing our forest fauna.

scholarly journals Metapopulations and Feeding Selectivity of Montane and Long-Tailed Voles (Microtus montanus and M. Longicaudus), and Hantavirus and Plague in the Jackson Hole Small Mammal Communtiy

1995 ◽  
Vol 19 ◽  
pp. 33-36
Author(s):  
Frederick Jannett, Jr.
Keyword(s):  
Small Mammals ◽  
Small Mammal ◽  
Ground Squirrels ◽  
Feeding Selectivity ◽  
Microtus Montanus ◽  
Human Contact ◽  
Jackson Hole ◽  
Demographic Processes ◽  
Study Sites

The purpose of the long-term research which began in 1971 on metapopulations of voles is to enumerate patterns in surviorship, reproduction, and morphology across sections of the metapopulations. The study sites for Microtus montanus were chosen to represent primary and secondary habitat and proximate and isolated habitat patches. The purpose of the work which commenced in 1989 is to ascertain how selectively Microtus montanus and M. longicaudus feed, and to assess vegetation as a factor in demographic processes of the two species . The purpose of the more recently initiated study on hantavirus started in 1994 is to ascertain the extent of hantavirus among as many species of small mammals as possible, to identify the strain(s), to understand the presence of hantavirus across species and among the metapopulations of voles, and to assess the potential for human contact. The purpose of the work on plague since 1995 is to test the long-standing hypothesis that voles are a reservoir in the intervals between plague outbreaks among ground squirrels.

scholarly journals Metapopulations of Montane and Long-Tailed Voles (Microtus montanus and M. longicaudus), and Hantavirus and Plague in the Jackson Hole Small Mammal Community

1996 ◽  
Vol 20 ◽  
pp. 52-56
Author(s):  
Frederick Jannett, Jr.
Keyword(s):  
Small Mammals ◽  
Small Mammal ◽  
Ground Squirrels ◽  
Habitat Patches ◽  
Microtus Montanus ◽  
Human Contact ◽  
Jackson Hole ◽  
Small Mammal Community ◽  
Study Sites

The purpose of the long-term research begun in 1971 on metapopulations of voles is to enumerate patterns in survivorship, reproduction, and morphology across the sections of the metapopulations. The study sites for Microtus montanus were chosen to represent primary and secondary habitat, and proximate and isolated habitat patches. The purpose of the research on hantavirus begun in 1994 is to ascertain the extent of hantavirus among as many species of small mammals as possible, to identify the strain(s), to understand the presence of hantavirus across species and among the metapopulations of voles, and to assess the potential for human contact. The purpose of the research on plague begun in 1995 is to test the long-standing hypothesis that voles are a reservoir in the intervals between plague outbreaks among ground squirrels.

scholarly journals Metapopulations of Montane and Long-Tailed Voles (Microtus montanus and M. longicaudus), and Hantavirus and Plague in the Jackson Hole Small Mammal Community

1997 ◽  
Vol 21 ◽  
pp. 29-32
Author(s):  
Frederick Jannett, Jr.
Keyword(s):  
Small Mammals ◽  
Small Mammal ◽  
Ground Squirrels ◽  
Habitat Patches ◽  
Microtus Montanus ◽  
Human Contact ◽  
Jackson Hole ◽  
Small Mammal Community ◽  
Study Sites

The purpose of the long-term research begun in 1971 on metapopulations of voles is to enumerate patterns in survivorship, reproduction, and morphology across the sections of the metapopulations. The study sites for Microtus montanus were chosen to represent primary and secondary habitat, and proximate and isolated habitat patches. The purpose of the research on hantavirus begun in 1994 is to ascertain the extent of hantavirus among as many species of small mammals as possible, to identify the strain(s), to understand the presence of hantavirus across species and among the metapopulations of voles, and to assess the potential for human contact. The purpose of the research on plague begun in 1995 is to test the long-standing hypothesis that voles are a reservoir in the intervals between plague outbreaks among ground squirrels.

scholarly journals Metapopulations and Feeding Selectivity of Montane and Long-Tailed Voles Microtus montanus and M. Longicaudus, and Hantavirus in the Jackson Hole Small Mammal Community

1994 ◽  
Vol 18 ◽  
pp. 52-55
Author(s):  
Frederick Jannett, Jr.
Keyword(s):  
Small Mammals ◽  
Small Mammal ◽  
Feeding Selectivity ◽  
Microtus Montanus ◽  
Human Contact ◽  
Jackson Hole ◽  
Small Mammal Community ◽  
Demographic Processes ◽  
Study Sites

The purposes of the long-term research on metapopulations of voles begun in 1971 are to enumerate patterns in survivorship and reproduction across the sections of the metapopulations, and concomitant variation in morphology. The study sites for Microtus montanus were chosen to represent primary and secondary habitat, and proximate and isolated habitat patches. The purpose of the research begun in 1989 is to ascertain how selectively Microtus montanus and M. longicaudus feed, and to assess vegetation as a factor in demographic processes of the two species. The purpose of the research on hantavirus begun in 1994 is to ascertain the extent of hantavirus among as many species of small mammals as possible, to identify the strain(s), to understand the presence of hantavirus across species and among the metapopulations of voles, and to assess the potential for human contact.

scholarly journals Environmental Assessment at the Bakhuis Bauxite Concession: Small- Sized Mammal Diversity and Abundance in the Lowland Humid Forests of Suriname

2009 ◽  
Vol 2 (1) ◽  
pp. 42-53 ◽  
Author(s):  
Burton K. Lim
Keyword(s):  
Small Mammals ◽  
Relative Abundance ◽  
Small Mammal ◽  
Social Impact ◽  
Climatic Conditions ◽  
Wet Season ◽  
Natural Habitats ◽  
Small Areas ◽  
Study Sites ◽  
Molossus Molossus

A small mammal survey was conducted in the Bakhuis Mountains of western Suriname in South America as part of a larger environmental and social impact assessment for a proposed bauxite mining concession. The objectives were to establish a baseline study of species diversity and relative abundance for comparison of seasonality, areas, and habitats to facilitate the identification and monitoring of potential impacts of mining to the environment. There were 83 species of small mammals documented comprising 68 species of bats, 8 species of rats and mice, and 7 species of opossums. The most abundant bat was the Seba’s short-tailed bat, Carollia perspicillata Linnaeus, which was recorded at all six study sites. The most abundant non-volant small mammal was the Guianan spiny rat, Proechimys guyannensis E. Geoffroy. Noteworthy discoveries during the survey include the documentation of four species of bats new to the fauna of Suriname (Cyttarops alecto Thomas, smoky sheath-tailed bat; Saccopteryx gymnura Thomas; least two-lined sac-winged bat; Diaemus youngi Jentink; bird-feeding vampire bat; and Lasiurus egregius Peters, greater red bat). There were no obvious differences between the dry and wet season samplings that were attributable directly to climatic conditions. In terms of spatial variation, the relative abundance of bats among the five study sites within the concession area was similar to each other, but significantly different from a sixth study site at a nearby ecotourism operation, which had large numbers of three species (C. perspicillata; Molossus molossus, common free-tailed bat; and Sturnira lilium, little yellowshouldered bat) that are better adapted to human modified surroundings. This suggests that the recent mining explorations in Bakhuis have had a relatively minor impact on bats and that the otherwise pristine forests within the concession can tolerate low levels of disturbance in proportionally small areas over a short duration. For specific habitats, the xeric forest on plateaus had a reduced subset of species of small mammals that were found in the mesic forest of the surrounding lowland regions, which was acting as a species reservoir for upland areas. Small mammals, in particular bats as primary seed dispersers and flower pollinators, are important components of the ecosystem for the successful reforestation of natural habitats, and factors related to community structure are good indicators of the health of the environment.

Effects of altitude and vegetation on small-mammal distribution in the Urucum Mountains, western Brazil

2011 ◽  
Vol 27 (03) ◽  
pp. 279-287 ◽  
Author(s):  
Nilton Carlos Caceres ◽  
Maurício Neves Godoi ◽  
Wellington Hannibal ◽  
Vanda Lúcia Ferreira
Keyword(s):  
Small Mammals ◽  
Small Mammal ◽  
Vegetation Type ◽  
Randomization Tests ◽  
Biogeographic Region ◽  
Live Trap ◽  
Small Mammal Community ◽  
Community Variation ◽  
Abundance And Diversity ◽  
Mammal Distribution

Abstract:We conducted a study on small-mammal composition, abundance and diversity across altitudinal and vegetational gradients in the Urucum Mountains (from 150 to 1000 m asl) in western Brazil, a complex biogeographic region. Small mammals were collected in 31 sampling units distributed along altitudinal and vegetational gradients (forest and grassland), totalling 18 112 trap-nights for pitfall and 3500 trap-nights for live-trap. Community variation among sampling units was assessed by randomization tests, setting altitude, vegetation, locality and time as factors, and using presence/absence data. Correlation and logistic regression analyses were run for species and diversity along gradients of altitude and vegetation, according to abundance and presence/absence data. Nineteen species (seven marsupial and 12 rodent) and 355 individuals were recorded. The species composition of small mammals differed according to altitude, vegetation type, locality and time. Species diversity varied significantly according to altitude. Species were influenced solely by altitude or vegetation, or by both vegetation and altitude concomitantly. The small-mammal community was divided in two groups according to biogeographic affinities. The grassland group is capable of invading forest habitats. The results are discussed in light of current hypotheses that attempt to explain community variation along altitudinal gradients around the world.

scholarly journals Response of small mammals and birds to partial cutting and clearcutting in northwest British Columbia

1998 ◽  
Vol 74 (5) ◽  
pp. 703-713 ◽  
Author(s):  
J. D. Steventon ◽  
K. L. MacKenzie ◽  
T. E. Mahon
Keyword(s):  
British Columbia ◽  
Small Mammals ◽  
Small Mammal ◽  
Forest Cover ◽  
Bird Species ◽  
Timber Harvest ◽  
Wildlife Habitat ◽  
Meadow Vole ◽  
Partial Cutting ◽  
Significant Difference

A challenge facing forest managers is providing habitats for wildlife associated with mature or old-growth forests. One approach is to use partial cutting which maintains forest cover while still allowing timber harvest. We compared small mammal (voles, mice and shrews) and bird abundance after two intensities of partial cutting (30% and 60% volume removal) to clearcuts and uncut natural stands in coast-interior transitional forests of British Columbia. The 30% removal resulted in no significant difference in the bird community compared to the uncut stands, while southern red-backed voles (Clethrionomys gapperi) increased in abundance. Bird and small mammal communities in the 60% removal treatment were closer to the uncut forest than to clearcuts, but also included species typical of clearcuts. At least one bird species, Yellow-rumped Warbler (Dendroica coronata), was most abundant in the 60% removal treatment. Several species such as the meadow vole (Microtus pennsylvanicus) and Dark-eyed Junco (Junco hyemalis) were most abundant in clearcuts, and Lincoln's Sparrow (Melospiza lincolnii) and Chipping Sparrow (Spizella passerina) were almost exclusively found in clearcuts. Scattered aspen and birch trees left in two of the clearcuts were used as cavity nest trees by Red-breasted Sapsuckers (Sphyrapicus ruber), Hairy Woodpeckers (Picoides villosus), and Tree Swallows (Tachycineta bicolor). We concluded that both of the partial cutting treatments provided habitat for small mammals and birds typical of mature forest, although the heavy removal began to show a shift towards species typical of clearcuts. Because no single treatment was optimal for all species, we recommend that partial cutting be part of a landscape strategy to provide a range of habitat conditions similar to those occurring under natural disturbance regimes. Key words: Partial cutting, clearcutting, silvicultural systems, wildlife habitat, biodiversity, ecosystem management, birds, small mammals

scholarly journals Towards quantifying changes in forest cover in the Araucaria forest-grassland mosaic in southern Brazil

2021 ◽  
Author(s):  
Daniela Piraquive Bermúdez ◽  
Martin Theuerkauf ◽  
Thomas Giesecke
Keyword(s):  
Protected Areas ◽  
Vegetation Cover ◽  
Forest Cover ◽  
Vegetation Type ◽  
Model Development ◽  
Pollen Dispersal ◽  
Individual Species ◽  
Araucaria Angustifolia ◽  
Southern Brazil ◽  
Pollen Productivity

AbstractQuantitative estimates of past vegetation cover are needed both regionally so human-landscape interactions can be better understood, and globally to evaluate the effects of changing vegetation cover on the climate system. Models reducing the bias in the pollen representation of vegetation cover have been developed in the temperate regions of the northern hemisphere, while experience applying them in other parts of the world is limited. The Araucaria forest-grassland mosaic of southern Brazil is an area where open and forested plant communities exist naturally and have changed their cover over time due to changing climate and human activities. Therefore, this area is of particular interest for such studies. Modern pollen and vegetation comparisons were carried out in two protected areas: Vila Velha State Park in Paraná state and Aparados da Serra National Park in Rio Grande do Sul. Vegetation mapping and analysis focused on Araucaria angustifolia as the characteristic tree of this vegetation type. In the Araucaria forest-grassland mosaic open vegetation and woodland change at a scale of hundreds of metres. These changes are difficult to capture based on pollen proportions in surface samples. While the abundance of Poaceae pollen is not a good indicator of locally open conditions, several pollen taxa can be used as indicators of the local vegetation cover. Pollen vegetation ratios (R-values) compare well between the two study regions, indicating that pollen production of individual species within the large plant families of Poaceae and Asteraceae are similar within the overall region. Araucaria angustifolia pollen is underrepresented with regards to its vegetation cover, while Poaceae are among the highest pollen producers in the region. Diverse woodland species other than A. angustifolia were grouped as one forest taxon and as the species composition of woodlands differed between the two study areas, so did the estimated pollen productivity of this group. It would be rewarding in future investigations to estimate pollen productivity for groups of trees with the same pollen dispersal syndrome. The application of pollen dispersal models designed for closed canopy in the protected areas was challenging. Further model development is required to deal with pollen released at different levels in semi-open vegetation types.

Understory use by terrestrial small mammals in an unflooded forest patch in the Pantanal floodplain

Mammalia ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Nayara Yoshie Sano ◽  
Heitor Miraglia Herrera ◽  
Grasiela Edith de Oliveira Porfirio ◽  
Filipe Martins Santos
Keyword(s):  
Small Mammals ◽  
Small Mammal ◽  
Understory Vegetation ◽  
Monodelphis Domestica ◽  
Forest Patch ◽  
Habitat Features ◽  
Species Characteristics ◽  
Local Habitat

AbstractTo date, there have been no studies that have evaluated small mammal utilization of the understory of forests. In this study, we described the use of vertical strata by small mammals in patches of unflooded forests, known as “cordilheiras”, in the Nhecolândia sub-region of the Pantanal, Brazil. We collected all species using the ground and understory, including the terrestrial didelphid Monodelphis domestica. We suppose that local habitat features (e.g., Acuri palms), rather than intrinsic species characteristics, may be more conducive to the use of understory vegetation by small mammals in the Nhecolândia region.

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