Geology topics

Petra Wood

Publications and source records attributed to Petra Wood.

8 recordsLinked to original sources

USGS2016

Louisiana waterthrush and benthic macroinvertebrate response to shale gas development

Because shale gas development is occurring over large landscapes and consequently is affecting many headwater streams, an understanding of its effects on headwater-stream faunal communities is needed. We examined effects of shale gas development (well pads and associated infrastructure) on Louisiana waterthrush Parkesia motacilla and benthic macroinvertebrate communities in 12 West Virginia headwater streams in 2011. Streams were classed as impacted ( n = 6) or unimpacted ( n = 6) by shale gas development. We quantified waterthrush demography (nest success, clutch size, number of fledglings, territory density), a waterthrush Habitat Suitability Index, a Rapid Bioassessment Protocol habitat index, and benthic macroinvertebrate metrics including a genus-level stream-quality index for each stream. We compared each benthic metric between impacted and unimpacted streams with a Student's t -test that incorporated adjustments for normalizing data. Impacted streams had lower genus-level stream-quality index scores; lower overall and Ephemeroptera, Plecoptera, and Trichoptera richness; fewer intolerant taxa, more tolerant taxa, and greater density of 0–3-mm individuals ( P ≤ 0.10). We then used Pearson correlation to relate waterthrush metrics to benthic metrics across the 12 streams. Territory density (no. of territories/km of stream) was greater on streams with higher genus-level stream-quality index scores; greater density of all taxa and Ephemeroptera, Plecoptera, and Trichoptera taxa; and greater biomass. Clutch size was greater on streams with higher genus-level stream-quality index scores. Nest survival analyses ( n = 43 nests) completed with Program MARK suggested minimal influence of benthic metrics compared with nest stage and Habitat Suitability Index score. Although our study spanned only one season, our results suggest that shale gas development affected waterthrush and benthic communities in the headwater streams we studied. Thus, these ecological effects of shale gas development warrant closer examination.

West Virginia↗

USGS2016

Shale gas development effects on the songbird community in a central Appalachian forest

In the last decade, unconventional drilling for natural gas from the Marcellus-Utica shale has increased exponentially in the central Appalachians. This heavily forested region contains important breeding habitat for many neotropical migratory songbirds, including several species of conservation concern. Our goal was to examine effects of unconventional gas development on forest habitat and breeding songbirds at a predominantly forested site from 2008 to 2015. Construction of gas well pads and infrastructure (e.g., roads, pipelines) contributed to an overall 4.5% loss in forest cover at the site, a 12.4% loss in core forest, and a 51.7% increase in forest edge density. We evaluated the relationship between land-cover metrics and species richness within three avian guilds: forest-interior, early-successional, and synanthropic, in addition to abundances of 21 focal species. Land-cover impacts were evaluated at two spatial extents: a point-level within 100-m and 500-m buffers of each avian survey station, and a landscape-level across the study area (4326 ha). Although we observed variability in species-specific responses, we found distinct trends in long-term response among the three avian guilds. Forest-interior guild richness declined at all points across the site and at points impacted within 100 m by shale gas but did not change at unimpacted points. Early-successional and synanthropic guild richness increased at all points and at impacted points. Our results suggest that shale gas development has the potential to fragment regional forests and alter avian communities, and that efforts to minimize new development in core forests will reduce negative impacts to forest dependent species.

Biological Conservation↗

USGS2016

Reproductive success and habitat characteristics of Golden-winged Warblers in high-elevation pasturelands

The Golden-winged Warbler ( Vermivora chrysoptera ) is one of the most rapidly declining vertebrate species in the Appalachian Mountains. It is the subject of extensive range-wide research and conservation action. However, little is known about this species' breeding ecology in high-elevation pasturelands, a breeding habitat with conservation potential considering the U.S. Natural Resource Conservation Service's Working Lands for Wildlife program targeting private lands in the Appalachian Mountains. We located 100 nests of Golden-winged Warblers in pastures in and around the Monongahela National Forest in West Virginia during 2008–2012. Daily nest survival rate (mean ± SE = 0.962 ± 0.006), clutch size (4.5 ± 0.1), and number of young fledged per nest attempt (2.0 ± 0.2) and successful nest (4.0 ± 0.1) fell within the range of values reported in other parts of the species' range and were not significantly affected by year or the presence/absence of cattle grazing. Classification tree analysis revealed that nests were in denser vegetation (≥52%) and closer to forest edges (<36.0 m) and shrubs (<7.0 cm) than random locations within the male's territory. Successful nests had significantly more woody cover (≥9%) within 1 m than failed nests. Our results suggest that cattle grazing at 1.2–2.4 ha of forage/animal unit with periodic mowing can create and maintain these characteristics without interfering with the nesting of Golden-winged Warblers. High-elevation pasturelands may provide a refuge for remaining populations of Golden-winged Warblers in this region.

Wilson Journal of Ornithology↗

USGS2016

Golden-winged Warbler nest-site habitat selection: Chapter 7

Avian habitat selection occurs at multiple spatial scales to incorporate life history requirements. Breeding habitat of Golden-winged Warblers ( Vermivora chrysoptera ) is characterized by largely forested landscapes containing natural or anthropogenic disturbance elements that maintain forest patches in early stages of succession. Breeding habitat occurs in a variety of settings, including shrub and forest swamps, regenerating forests following timber harvest, grazed pastures, and reclaimed mined lands. We identified structural components of nest sites for Golden-winged Warblers by measuring habitat characteristics across five states (North Carolina, New York, Pennsylvania, Tennessee, and West Virginia) in the Appalachian breeding-distribution segment and two states (Minnesota and Wisconsin) in the Great Lakes breeding-distribution segment. We measured habitat characteristics at the nest-site scale with a series of nested plots characterizing herbaceous vegetation (grasses and forbs), woody shrubs and saplings, and overstory trees. We measured similar variables at paired random plots located 25–50 m from the nest within the same territory to evaluate selection. We used conditional logistical regression to identify which parameters were important in habitat selection and Simple Saddlepoint Approximation (SSA) to aid in management interpretation of identified parameters for each study site. Study site was an important determinant for which parameters were significant in nest-site selection, although selection for some parameters was consistent across sites. The amount of woody cover at the nest-site scale was consistently present in the top nest-site selection models across sites, although the direction of the relationship was not the same across all sites. We also identified grass, forb, woody cover, and vegetation density as important components of Golden-winged Warbler nest-site selection. Based on SSA, we identified vegetation thresholds to aid in designing habitat management prescriptions to promote creation or restoration of Golden-winged Warbler nesting habitat across the eastern portion of their breeding distribution.

Studies in Avian Biology↗

USGS2016

Space and habitat use by breeding Golden-winged Warblers in the central Appalachian Mountains

Spot-mapping, or recording locations of observed use by territorial songbirds, is often used to delineate core breeding territories. However, a recent radiotelemetry study in Minnesota found that male Golden-winged Warblers ( Vermivora chrysoptera ) occurring in high-density populations used resources outside their spot-mapped territories. We compared differences in space use and quantified vegetation characteristics in territories and home ranges of individual male Golden-winged Warblers that we monitored using both spot-mapping and radiotelemetry. Our study sites in Pennsylvania and West Virginia had lower population density than in Minnesota. We recorded 524 telemetry locations among 12 male Golden-winged Warblers in Pennsylvania and 488 telemetry locations among seven males in West Virginia. Telemetry-delineated home ranges (100% and 50% minimum convex polygons [MCPs]) were two to four times larger than spot-mapped territories. Spot-mapped territories had minimal overlap among individual males, but home ranges had extensive space-use overlap in both the number and amount of MCP overlap among several males. Forty percent of telemetry locations were outside of spot-mapped territories. Sapling abundance was greater in home ranges (mean 22.5 saplings ± 2.1 SE) than spot-mapped territories in Pennsylvania (11.8 ± 1.9). In managed pastures of West Virginia, tree abundance was greater in home ranges (7.3 trees ± 0.8) than spot-mapped territories (1.9 ± 0.6). More telemetry locations than spot-mapped locations occurred in forest in both states, and telemetry locations were closer to intact forested edges of shrublands than spot-mapped locations in West Virginia. On several occasions, we observed radiomarked individuals >200 m (maximum of 1.5 km) from their MCP spot-mapped territory boundaries. Why Golden-winged Warblers leave their spot-mapped territories is unknown, but our observations suggest foraging, forays for extra-pair mating, and reconnaissance for postbreeding movements as possible motives. Our results from areas with low Golden-winged Warbler territory densities are similar to patterns reported for a high-density population in Minnesota. Ultimately, spot-mapping alone does not accurately reflect space use of Golden-winged Warblers during the breeding season, nor does it characterize all cover types used even in areas with relatively low territory densities. Current conservation plans for Golden-winged Warblers that are based on habitat characteristics measured within spot-mapped territories or at the landscape scale may not adequately incorporate space use at intermediate spatial scales of clusters of territories or home ranges.

Studies in Avian Biology↗

USGS2015

Grasshopper sparrow reproductive success and habitat use on reclaimed surface mines varies by age of reclamation

We studied 3 mountaintop mining–valley fill (MTMVF) complexes in southern West Virginia, USA to examine grasshopper sparrow ( Ammodramus savannarum pratensis ) demographic response to different age classes of mine land reclamation. For 71 nests monitored during the 2001–2002 breeding seasons, overall nest success (36%) was within the range of nest success rates previously reported for this species, but it was highest on more recently reclaimed sites (56%). Nest density and clutch size did not differ ( P  > 0.30) among reclamation age classes, whereas number of fledglings was greater ( P  = 0.01) on more recently reclaimed sites. We measured vegetation variables at 70 nest subplots and at 96 systematic subplots to compare nest vegetation with vegetation available on the plots. We found that nests occurred in areas with more bare ground near the nest, greater vegetation height–density surrounding the nest site, lower grass height, and fewer woody stems, similar to previous studies. As postreclamation age increased, vegetation height–density and maximum grass height increased, and sericea ( Lespedeza cuneata ) became more dominant. Nest success declined with increasing vegetation height–density at the nest. The grasslands available on these reclaimed mine complexes are of sufficient quality to support breeding populations of grasshopper sparrows, but nest success decreased on the older reclaimed areas. Without active management, grasslands on reclaimed MTMVF mines become less suitable for nesting grasshopper sparrows about 10 years after reclamation.

West Virginia↗

USGS2013

Management guidelines for enhancing Cerulean Warbler breeding habitat in Appalachian hardwood forests

The Cerulean Warbler (Setophaga cerulea) is a migratory songbird that breeds in mature deciduous forests of eastern North America. Cerulean Warblers (hereafter, ceruleans) require heavily forested landscapes for nesting and, within Appalachian forests, primarily occur on ridge tops and steep, upper slopes. They are generally associated with oakdominated (Quercus spp.) stands that contain gaps in the forest canopy, that have large diameter trees (>16 inches diameter breast height (dbh)), and that have well-developed understory-and upper-canopy layers. Ceruleans primarily use the midand upper-canopy where they glean insects from the surface of leaves and conceal their open cup nests. Because they are severely declining across much of their range (Fig. 1), habitat management is a high priority. Management for this species can also improve conditions for a number of other wildlife species that depend on the same structure.

Appalachian Mountains↗

USGS2010

Influence of cover and food resource variation on postbreeding bird use of timber harvests with residual canopy trees

We investigated avian use of clearcuts and two-age harvests during the post-breeding period in 2006 in the central Appalachians, West Virginia, USA with an information-theoretic approach to model selection. Cover variables appeared to be most important; e.g., vegetative vertical complexity had a strong positive relation with capture rates of mature forest birds and molting adults, as well as physical condition which supports a predator-avoidance hypothesis for habitat use. Basal area was a poor predictor of captures; residual trees near nets tended to depress capture rates. Food variables best explained capture rates for some species groups (e.g., early-successional insectivores and granivores, mature forest nesting adults, molting birds), but post-breeding habitat quality was based primarily on vegetative cover. Habitat use may depend on the bird's physical condition and molt status, and we found evidence for age-specific differences which may impact survival. Our study suggests important links between post-breeding habitat quality, molt status, physical condition, and bird age, and indicates a variety of response variables (relative abundance, survival, body condition) should be measured to assess avian habitat quality during the post-breeding period.

West Virginia↗