Skip to main content
USGS - science for a changing world
Advanced Search

Filters: Tags: sub-regional (X) > Types: OGC WFS Layer (X)

37 results (32ms)   

Filters
Date Range
Extensions
Types
Contacts
Categories
Tag Types
Tag Schemes
View Results as: JSON ATOM CSV
thumbnail
Synopsis: This study evaluates whether previous observations of a higher percentage of parasitism and parasitoid diversity in a complex agricultural landscape, relative to a simple landscape, represent a general phenomenon. Rates of parasitism and parasitoid diversity of the armyworm (Pseudaletia unipuncta) were assessed in three replicate (Onondaga, Ingham, and Benton) regions in southern Michigan. Within each region, a simple landscape (primarily cropland) and a complex landscape (cropland intermixed with mid and late successional noncrop habitats) were identified through analysis of aerial photographs. In each landscape, three maize fields were selected, and second to fourth instar P. unipuncta were released...
thumbnail
Synopsis: The purpose of this model is to indicate potential habitat for olive-backed pocket mice (Perohnathus fasciatus) within the Milk River Basin. As this is a landscape level model with course variaqbles, it may not be directly applicable to other areas for site-specific analysis. Conclusions: Olive-backed pocket mice require high proportions of grassland habitat and low proportions of shrub cover. Sites with low densities of shrubs are preferred because they provide cover from large and aerial predators, such as owls. A threshold of below 40% shrub coverage represents ideal shrub cover proportions.
thumbnail
Synopsis: Using multi-scale seasonal models, this study explored how broad scale landscape context and local resource heterogeneity influenced local resource selection among threatened forest-dwelling woodland caribou in southern Quebec. Caribou consistently avoided roads, however researchers identified thresholds in road proximity effects. The threshold distance at which caribou avoid roads is 1.25 km for active roads and 0.75 km from derelict roads. Open lichen woodlands were an important cover type for caribou during winter and spring, whereas deciduous forests, wetlands, and even young disturbed stands became important during calving and summer. Landscape cover type and amount explained more variation in habitat...
thumbnail
Synopsis: In an attempt to better characterize the influence of human settlement patterns on wolf distribution, this paper examined how radio-collared gray wolves responded to different road types and human presence at the boundaries of Kenai National Wildlife Refuge in south-central Alaska. Wolves tended to avoid oilfield access roads that were open to the public, but were attracted to gated pipeline access roads and secondary gravel roads with limited human use. The low use access and secondary roads likely provided an easy travel corridor for wolves. Prior to intensive trapping and hunting from 1978-1979, wolves demonstrated little territorial adjustment in response to a heavily used highway. However, only after...
thumbnail
Conclusions: Grizzly bears can use roaded habitats, but spatial avoidance will increase and survival will decrease as traffic levels, road densities and human settlement increases. Road density standards and road closure programmes should be developed and that these programmes incorporate seasonal habitat requirements of grizzly bears. Thresholds/Learnings: More than 80% of bear sitings occurred in blocks of undisturbed habitat >900 ha Synopsis: The study examined the relationships between grizzly bears, habitat and roads in the Swan Mountains, Montana. The study showed complex spatial and temporal relationships between grizzly bears and habitat resources. Resource selection was expressed relative to strength...
thumbnail
Synopsis: Remotely sensed data and GIS were used to compare the effects of clear-cutting and road-building on the landscape pattern of the Bighorn National Forest, Wyoming. Landscape patterns were quantified for each of 12 watersheds on a series of four maps that differed only in the degree of clear-cutting and road density. Researchers analyzed several landscape pattern metrics for the landscape as a whole and for the lodgepole pine and spruce/fir cover classes across the four maps to determine the relative effects of clear-cutting and road building on the pattern of each watershed. At both the landscape and cover class scales, clear-cutting and road building resulted in increased fragmentation as represented...
thumbnail
Synopsis: This report evaluates habitat requirements of the American badger according to parameters of soil texture, graminoid cover, slope, and proximity to roads. Badgers tend to prefer sandy loam and silty loam, medium and moderately coarse textured soils. In terms of graminoid coverage, badgers generally prefer open grassland habitat, but can also be found in agriculturally dominated landscapes containing isolated pockets of Richardson 's ground squirrel colonies. Graminoid coverage of 23% was chosen as the minimum requirement for suitable badger habitat. As slope increases, habitat suitability decreases to a point at which the likelihood of badgers existing there (i.e. cliffs and badlands) is extremely low...
thumbnail
Synopsis: This study investigates the relationships of landscape disturbance, altered prey resources, and rattlesnake populations in the Upper Snake River Plain of southeastern. Researchers used radio telemetry to track rattlesnakes while concurrently conducting habitat sampling and small mammal trapping in areas used by snakes and in random locations. Disturbed areas (by grazing and/or burning) were characterized by lower biological crust cover, shrub cover, shrub height, and shrub dispersion, as well as higher grass and bare soil cover. Disturbed areas were also characterized by lower proportions of small animal biomass, abundance, and large prey species (such as chipmunks), while the proportions Conclusions:...
thumbnail
Conclusions: The study recorded flushing responses (whether or not an animal fled in response to disturbance) and flush distances of 6 species of diurnal raptors exposed to walking and vehicle disturbances in order to calculate minimum distances for species-specific buffer zones. In general, walking disturbances resulted in more flushing than vehicle disturbances for all species except the prairie falcon. For walking disturbances, a linear relationship existed between flight distance and body mass, with lighter species flushing at shorter distances; however, this trend did not hold for vehicle disturbance. Birds flushed at much shorter distances in response to approaching vehicles. Thresholds/Learnings: Buffer...
thumbnail
Conclusions: Grizzly bears avoid high volume roads (25,000 vehicles/day). High quality habitat determines movement decisions relative to roads. Grizzly bears will cross high volume roads to access high-quality habitat. Grizzly bears use areas close to roads more than expected, in particular low-volume roads (10,000 vehicles/day). Prevent loss of habitat connectivity with the following mitigation: maintain high-quality habitat adjacent to roads, install continuous highway fencing and create wildlife passages. Thresholds/Learnings: Synopsis: The study examined the relationships among grizzly bears, their habitats and roads in Banff National Park, a protected area characterized by a major transportation corridor. This...
thumbnail
Conclusions: Few species were in fact influenced by grassland amount or fragmentation. In contrast, distance to edge and local vegetation characteristics had significant effects on densities and nest success of many species. Thresholds/Learnings: Great Plains toads thrive when >75% of the landscape is composed of native prairie components (i.e. shrubs, graminoids, riparian areas, lakes, wetlands, and trees) . Synopsis: In Alberta, Great Plains toads are found in the dry mixed grass of the southeastern corner of the province. Typical breeding habitat tends to be in shallow ponds with relatively fresh, clear water in sandy soil. In this report habitat suitability was evaluated for the Great Plains toad according...
thumbnail
Synopsis: This study examined the spatial patterns and factors influencing small terrestrial vertebrate road-kill aggregations in the Bow River Valley of Alberta, Canada. Mammal and bird road-kill indices were consistently higher on low volume parkway roads than on the high-speed, high volume Trans-Canada highway (TCH). Birds were more vulnerable to collisions than mammals on the TCH. Low volume parkway road-kills were less likely to occur on raised sections of road, and tended to occur close to vegetative cover far from wildlife passages and culverts. Highway sections with forested medians were less significant barriers to forest birds than open grassy medians. Since forest dwelling birds are reluctant to cross...
thumbnail
Conclusions: Successional changes resulting from a legacy of fire suppression and other agricultural and access disturbances combine to create the current hetergeneous landscape mosaic. Thresholds/Learnings: Synopsis: Disturbance is considered to be a major factor influencing landscape pattern and vegetation composition. However, the presettlement vegetation composition of three Ohio (U.S.A) counties was controlled largely by soil texture, soil drainage, and topography. In most cases, both disturbance regime and local site conditions can explain presettlement landscape pattern. This study examines the roles of edaphic conditions landscape features such as topography, and fire in contributing to (1) the abundance,...
thumbnail
Synopsis: The short-horned lizard is Alberta's only lizard. It is indigenous to semi-arid, short grass portions of the northern Great Plains and usually found in rather rough terrain. This report evaluated habitat suitability requirements for the short-horned lizard according to the following parameters: Topographical Features: Most of the daily movement patterns during the summer rarely exceeded 30m, and generally occurred along the slopes of the valleys or valley bottoms. Consequently, all valleys and all prairie habitat within 100m of valleys are considered the best potential habitat. Native Prairie Class: Native Prairie Class (NPC) is derived from the Native Prairie Vegetation Baseline Inventory developed...
thumbnail
Conclusions: Richardson's ground squirrels prefer short grass native prairie / pasture but can also occupy small isolated islands within cropland. These squirrels prefer open prairies and tend to select against heavily forested areas. *Note that this study generated landscape level models with coarse variables, and the thresholds and values used may not be directly applicable to other areas or for site-specific analysis. Thresholds/Learnings: A threshold amount of 20% graminoid coverage is the minimum suitable proportion for habitat suitability for Richarson's ground squirrel. Areas with less than 20% forest/shrub cover were considered sutiable habitat, while those greater than 40% were considered unsuitable*. ...
thumbnail
Conclusions: Valleys are the only areas capable of sustaining sufficient habitat for the butterfly species, Weidemeyer's Admiral. Consequently, all other areas (i.e. plains, uplands, benches, escarpments, plateaus) were deemed unsuitable. Additionally, areas devoid of shrub cover did not meet the habitat requirements of this specialized species. Thresholds/Learnings: Synopsis: Two variables were selected to model potential habitat for the butterfly species, Weidemeyer's Admiral. Topographical features derived from the Agricultural Region of Alberta Soils Inventory Database (AGRASID) and percent shrub cover derived from the Native Prairie Vegetation Baseline Inventory developed by Alberta Environment were used to...
thumbnail
Conclusions: Caribou mortalities attributed to wolf predation were generally closer to a corridor, indicating that linear corridors may enhance wolf predation efficiency. Therefore, caribou existing closer to linear corridors are at a higher risk of depredation than those farther from corridors. Thresholds/Learnings: Synopsis: This study tested the hypothesis that linear corridors affect caribou and wolf activities by examining the distribution of telemetry locations of caribou and wolves, as well as locations of caribou mortality and caribou predation by wolves relative to linear corridors caused by roads, seismic lines, power lines, and pipeline rights-of-way. Caribou mortalities attributed to wolf predation...
thumbnail
Conclusions: The proportion of sage-grouse nests located within 3 vs 5 km suggested that a 5 km buffer around a lek encompassed the majority of nests. The results indicate that land managers should strive to maintain a 5 km buffer around known sage-grouse lek locations in order to ensure sage-grouse breeding success. Thresholds/Learnings: A 5000m buffer around sage-grouse leks encompassed the majority (64%) of sage-grouse nests. Synopsis: This study used radio-telemetry to determine nesting patterns of Greater Sage-Grouse relative to leks in a relatively contiguous sagebrush habitat in Wyoming. The proportion of nests located within 3 vs 5 km suggested that a 5 km buffer around a lek encompassed the majority of...
thumbnail
Conclusions: Elk consistently selected for big basin sagebrush, greasewood, and tree cover; and consistently selected against Wyoming sagebrush, mixed shrub, and bare ground/sand. Selection patterns were similar during the winter, except big basin sagebrush and mixed shrubs were selected in proportion to their availability. Elk tend to prefer areas characterized by edge habitat where quality forage and cover habitats are in close proximity to one another. Thresholds/Learnings: Elk use was highest in summer in areas characterized by diverse habitats and >2800m away from major roads. High use areas during winter were similar, although elk tended to use areas slightly closer to roads (>2100m away), which is largely...


map background search result map search result map Great Plains Toad (Bufo cognatus) Weidemeyer's Admiral Distribution of caribou and wolves in relation to linear corridors Seasonal distribution and habitat use patterns of elk in the Jack Morrow Hills Planning Area Assessing the influence of resource co-variates at multiple spatial scales: an application to forest-dwelling caribou faced with intensive human activity. Gray wolf response to refuge boundaries and roads in Alaska. Linking landscape disturbance to the population ecology of Great Basin rattlesnakes (Crotalus oreganus lutosus) in the Upper Snake River Plain Spatial distribution of greater sage-grouse nests in relatively contiguous sagebrush habitats. Relationships among grizzly bears, highways, and habitat in Banff-Bow Valley, Alberta, Canada. Relationships among grizzly bears, roads, and habitat in the Swan Mountains, Montana. Richardson's Ground Squirrel. Effects of site, landscape features, and fire regime on vegetation patterns in presettlement southern Wisconsin Watershed analysis of forest fragmentation by clearcuts and roads in a Wyoming forest Short-horned Lizard Does agricultural landscape structure affect parasistism and parasitoid diversity? Olive-backed Pocket Mouse. Prairie Falcon. Response of wintering grassland raptors to human disturbance. Spatial patterns and factors influencing small vertebrate fauna road-kill aggregations. American Badger. Effects of site, landscape features, and fire regime on vegetation patterns in presettlement southern Wisconsin Relationships among grizzly bears, highways, and habitat in Banff-Bow Valley, Alberta, Canada. Seasonal distribution and habitat use patterns of elk in the Jack Morrow Hills Planning Area Weidemeyer's Admiral Short-horned Lizard American Badger. Assessing the influence of resource co-variates at multiple spatial scales: an application to forest-dwelling caribou faced with intensive human activity. Relationships among grizzly bears, roads, and habitat in the Swan Mountains, Montana. Response of wintering grassland raptors to human disturbance. Prairie Falcon. Olive-backed Pocket Mouse. Does agricultural landscape structure affect parasistism and parasitoid diversity? Distribution of caribou and wolves in relation to linear corridors Gray wolf response to refuge boundaries and roads in Alaska. Spatial patterns and factors influencing small vertebrate fauna road-kill aggregations. Spatial distribution of greater sage-grouse nests in relatively contiguous sagebrush habitats. Watershed analysis of forest fragmentation by clearcuts and roads in a Wyoming forest Linking landscape disturbance to the population ecology of Great Basin rattlesnakes (Crotalus oreganus lutosus) in the Upper Snake River Plain Great Plains Toad (Bufo cognatus) Richardson's Ground Squirrel.