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At least 91 records · Page 5Linked to original sources
USGS2004

Habitat selection by female northern pintails wintering in the Grassland Ecological Area, California

To determine relative importance of habitats available in the Grassland Ecological Area (GEA) to wintering female northern pintails, Anas acuta, we studied habitat use relative to availability (i.e., habitat selection) in the GEA during September through March, 1991-94 for 196 Hatch-Year (HY) and 221 After-Hatch-Year (AHY) female pintails that were radio tagged during August-early October in the GEA (n = 239), other San Joaquin Valley areas (n = 132), or other Central Valley areas (n = 46). Habitat availability and use varied among seasons and years, but pintails always selected shallow and, except on hunting days, open habitats. Swamp timothy, Heleochloa schoenoides, marsh was the most available, used, and selected habitat. Watergrass, Echinochloa crusgalli, marsh in the GEA was used less than available at night in contrast to previous studies in other SJV areas. Preferred late-winter habitats were apparently lacking in the GEA, at least relative to in the Sacramento Valley and Delta where most pintails moved to in December each year. Impacts on pintails of the increasing practice of managing marshes for increased emergent vegetation to attract other species should be monitored. Shallow, open habitats that produce seeds and invertebrates available to pintails in late winter would help maintain pintail abundance in the GEA.

California Fish and Game↗
USGS2010

Distribution and habitat use of king rails in the Illinois and Upper Mississippi River valleys

The migratory population of the king rail ( Rallus elegans ) has declined dramatically during the past 40 years, emphasizing the need to identify habitat requirements of this species to help guide conservation efforts. To assess distribution and habitat use of king rails along the Illinois and Upper Mississippi valleys, USA, we conducted repeated call-broadcast surveys at 83 locations in 2006 and 114 locations in 2007 distributed among 21 study sites. We detected king rails at 12 survey locations in 2006 and 14 locations in 2007, illustrating the limited distribution of king rails in this region. We found king rails concentrated at Clarence Cannon National Wildlife Refuge, an adjacent private Wetlands Reserve program site, and B. K. Leach Conservation Area, which were located in the Mississippi River floodplain in northeast Missouri. Using Program PRESENCE, we estimated detection probabilities and built models to identify habitat covariates that were important in king rail site occupancy. Habitat covariates included percentage of cover by tall (> 1 m) and short (<= 1 m) emergent vegetation, percentage of cover of woody vegetation, and interspersion of water and vegetation ( 2007 only) within 50 m of the survey location. Detection probability was 0.43 (SE = 0.12) in 2006 and 0.35 (SE = 0.03) in 2007 and was influenced by observer identity and percentage of cover by tall herbaceous vegetation. Site occupancy was 0.11 (SE = 0.04) in 2006 and 0.14 (SE = 0.04) in 2007 and was negatively influenced most by percentage of cover by woody vegetation. In addition, we found that interspersion of vegetation and water was positively related to occupancy in 2007. Thus, nesting king rails used wetlands that were characterized by high water-vegetation interspersion and little or no cover by woody vegetation. Our results suggest that biologists can improve king rail habitat by implementing management techniques that reduce woody cover and increase vegetation-water interspersion in wetlands.

Journal of Wildlife Management↗
USGS2023

Changes in habitat suitability for wintering dabbling ducks during dry conditions in the Central Valley of California

In arid and Mediterranean regions, landscape-scale wetland conservation requires understanding how wildlife responds to dynamic freshwater availability and conservation actions to enhance wetland habitat. Taking advantage of Landsat satellite data and structured and community science bird survey data, we built species distribution models to describe how three duck species, the Northern Pintail ( Anas acuta ), Green-winged Teal ( Anas crecca ), and Northern Shoveler ( Anas clypeata ), respond to freshwater supply and food resources on different flooded land cover types in the Central Valley of California. Specifically, our models compared duck habitat suitability between the wettest and driest conditions in each month from September through April. Using abundance-weighted boosted regression trees, we created three sets of species occurrence models based on different covariates: (1) near real-time (hereafter “real-time”) covariates in which duck observations were matched to the water availability within the 16-day window of a Landsat observation, (2) a combination of real-time covariates and waterfowl food resource covariates describing annual corn and rice biomass and managed wetland moist soil seed yield estimates derived from Landsat data, and (3) long-term average covariates—the most common approach to species distribution modeling—in which long-term average surface water availability was used. We modeled the monthly occurrence of three duck species as a function of surface water availability, land cover type, road density, temperature, and bird data source. We found that dry conditions result in reduced habitat suitability, with the biggest reductions in November through January and in agricultural fields; in contrast, suitability of flooded wetland habitat was relatively robust to surface water availability. When models of habitat suitability based on long-term average climate conditions were compared to models based on real-time conditions, the highest long-term suitability values occurred in areas where suitability was high regardless of whether it was a wet or a dry year. While all models performed well, the inclusion of crop and wetland plant yield covariates resulted in slightly higher model performance. Overall, species distribution models created using data on the environmental conditions present at the time of bird observations can aid conservation efforts under extreme conditions over large spatial scales.

California↗
USGS2011

Habitat use of nesting and brood-rearing King Rails in the Illinois and Upper Mississippi River Valleys

Most studies of King Rail ( Rallus elegans ) have investigated habitat use during the nesting season, while few comparisons have been made between the nesting and brood-rearing seasons. King Rails were located during the nesting season in Missouri using repeated surveys with call playback, and systematic searches for broods were conducted during the brood-rearing season. King Rail adults were located at twelve points in 2006 and 14 points in 2007, and five King Rail broods were located in each year. Water depth was measured and dominant cover type determined for randomly sampled 5-m plots within used and unused habitats. Logistic regression models were fitted to the data and top models were selected from the candidate set using AIC c . Nesting adults occurred more often in areas dominated by short (&le;1 m) emergent vegetation ( = 0.77 &plusmn; 0.27) and deeper water ( = 0.05 &plusmn; 0.02). Broods occurred more often in areas dominated by short emergent vegetation ( = 1.19 &plusmn; 0.37) and shallow water ( = -0.17 &plusmn; 0.06), and avoided areas dominated by tall (>1 m) emergent vegetation ( =-1.15 &plusmn; 0.45). A modified catch-curve analysis was used to estimate chick daily survival rates during selected 7-day periods for each year. Daily survival rate ranged from 0.92 &plusmn; 0.008 in late June 2007 to 0.96 &plusmn; 0.005 in late July 2006. Management plans for King Rails should include the different habitat types needed during the nesting and brood-rearing stages.

Waterbirds↗
USGS2010

Habitat use by female mallards in the lower Mississippi alluvial valley

Mallard ( Anas platyrhynchos ) populations in the lower Mississippi Alluvial Valley (LMAV), USA, historically averaged 1.6 million and represented the largest concentrations of wintering mallards in North America. Effective management of this wintering population requires current information on use of habitats. Accordingly, we employed radiotelemetry techniques to assess proportional use of habitats by female mallards during winters 2004-2005 and 2005-2006. We divided winters into 4 time periods defined by hunting seasons (FIRST, SPLIT, SECOND, and POST) and recorded diurnal and nocturnal locations. We examined variations in proportional use of habitats and use of areas closed to hunting due to effects of age (immature or ad), winter (2004-2005 or 2005-2006), time period (SECOND or POST), individual female, and all potential interactions of these effects, using locations recorded during the latter 2 time periods. We found that diurnal and nocturnal proportional use of habitats varied inconsistently among time periods and winters. Mean proportional use of forested wetlands ranged from 0.475 to 0.816 and from 0.428 to 0.764 during diurnal and nocturnal sampling periods, respectively. Diurnal proportional use of areas closed to hunting varied inconsistently among time periods and winters. Mean proportional use of areas closed to hunting ranged from 0.183 to 0.423 during diurnal sampling periods. Nocturnal use of areas closed to hunting varied inconsistently among female ages and time periods and among female ages and winters. Mean proportional use of areas closed to hunting ranged from 0.211 to 0.445 during nocturnal sampling periods. Our research suggests that forested wetlands in the LMAV provide important wintering habitats for female mallards; continued restoration and establishment of these habitats should benefit female mallards.

Journal of Wildlife Management↗
USGS2001

Estimates of evapotranspiration from the Ruby Lake National Wildlife Refuge area, Ruby Valley, northeastern Nevada, May 1999–October 2000

The Ruby Lake National Wildlife Refuge in Ruby Valley, Nevada, contains the largest area of perennial wetlands in northeastern Nevada and provides habitat to a large number of migratory and nesting waterfowl. The long-term preservation of the refuge depends on the availability of sufficient water to maintain optimal habitat conditions. In the Ruby Valley water budget, evapotranspiration (ET) from the refuge is one of the largest components of natural outflow. To help determine the amount of inflow needed to maintain wetland habitat, estimates of ET for May 1999 through October 2000 were made at major habitats throughout the refuge. The Bowen-ratio method was used to estimate daily ET at four sites: over open water, in a moderate-to-dense cover of bulrush marsh, in a moderate cover of mixed phreatophytic shrubs, and in a desert-shrub upland. The eddy-correlation method was used to estimate daily ET for periods of 2 to 12 weeks at a meadow site and at four sites in a sparse-to-moderate cover of phreatophytic shrubs. Daily ET rates ranged from less than 0.010 inch per day at all of the sites to a maximum of 0.464 inch per day at the open-water site. Average daily ET rates estimated for open water and a bulrush marsh were about four to five times greater than in areas of mixed phreatophytic shrubs, where the depth to ground water is less than 5 feet. Based on the seasonal distribution of major habitats in the refuge and on winter and summer ET rates, an estimated total of about 89,000 acre-feet of water was consumed by ET during October 1999-September 2000 (2000 water year). Of this total, about 49,800 acre-feet was consumed by ET in areas of open water and bulrush marsh.

Nevada↗
USGS2020

Inter-population differences in salinity tolerance of adult wild Sacramento splittail: osmoregulatory and metabolic responses to salinity

The Sacramento splittail ( Pogonichthys macrolepidotus ) is composed of two genetically distinct populations endemic to the San Francisco Estuary (SFE). The allopatric upstream spawning habitat of the Central Valley (CV) population connects with the sympatric rearing grounds via relatively low salinity waters, whereas the San Pablo (SP) population must pass through the relatively high-salinity Upper SFE to reach its allopatric downstream spawning habitat. We hypothesize that if migration through SFE salinities to SP spawning grounds is more challenging for adult CV than SP splittail, then salinity tolerance, osmoregulatory capacity, and metabolic responses to salinity will differ between populations. Osmoregulatory disturbances, assessed by measuring plasma osmolality and ions, muscle moisture and Na + -K + -ATPase activity after 168 to 336 h at 11‰ salinity, showed evidence for a more robust osmoregulatory capacity in adult SP relative to CV splittail. While both resting and maximum metabolic rates were elevated in SP splittail in response to increased salinity, CV splittail metabolic rates were unaffected by salinity. Further, the calculated difference between resting and maximum metabolic values, aerobic scope, did not differ significantly between populations. Therefore, improved osmoregulation came at a metabolic cost for SP splittail but was not associated with negative impacts on scope for aerobic metabolism. These results suggest that SP splittail may be physiologically adjusted to allow for migration through higher-salinity waters. The trends in interpopulation variation in osmoregulatory and metabolic responses to salinity exposures support our hypothesis of greater salinity-related challenges to adult CV than SP splittail migration and are consistent with our previous findings for juvenile splittail populations, further supporting our recommendation of population-specific management.

California↗
USGS2024

A comparison of water-quality and stormwater inflow and outflow during habitat restoration at the McEwen storm drainage pond, South Valley, Albuquerque, New Mexico, 2020–22

In 2020, the U.S. Geological Survey began targeted monitoring, in partnership with Bernalillo County, at three locations within the McEwen storm drainage pond to evaluate and compare the water quality of stormwater as it enters and exits the study area, which is channelized and routes urban stormwater runoff through a wetland area. Stage in McEwen pond and precipitation at a nearby precipitation gage were evaluated to observe relations between rainfall and stage, as well as how long the stage remained elevated at the site. Peak stage ranged from 0.73 to 2.4 feet, with the time to reach peak stage at McEwen pond ranging from 45 minutes to 10 hours and 45 minutes. The stage remained elevated for a median of 3 days. Monitored water-quality parameters included physical parameters, bacteria, sediment, and nutrients. Bacteria was the only parameter that frequently exceeded the New Mexico Water Quality standard. Significant differences (p less than 0.05) among sites were few, consisting of those for total nitrogen and dissolved ammonia concentrations, which decreased toward the middle of the pond and were lower in the outflow from the pond compared to concentrations at the east and west sites. The middle of McEwen pond showed an increase in the percentage of fine-grained sediment, which suggests that larger particles settled into the pond and were further filtered as water traveled through the swales. Concentrations of suspended sediment and dissolved nutrients were significantly lower in 2022 compared to previous years. Although the site is still undergoing restoration and plants are becoming established, observations over the last several years indicate that site restoration has resulted in changes to the study area through processes such as nutrient uptake and the filtering of larger sediment particles.

New Mexico↗
USGS2009

Baseline Channel Geometry and Aquatic Habitat Data for Selected Streams in the Matanuska-Susitna Valley, Alaska

Small streams in the rapidly developing Matanuska-Susitna Valley in south-central Alaska are known to support anadromous and resident fish but little is known about their hydrologic and riparian conditions, or their sensitivity to the rapid development of the area or climate variability. To help address this need, channel geometry and aquatic habitat data were collected in 2005 as a baseline of stream conditions for selected streams. Three streams were selected as representative of various stream types, and one drainage network, the Big Lake drainage basin, was selected for a systematic assessment. Streams in the Big Lake basin were drawn in a Geographic Information System (GIS), and 55 reaches along 16 miles of Meadow Creek and its primary tributary Little Meadow Creek were identified from orthoimagery and field observations on the basis of distinctive physical and habitat parameters, most commonly gradient, substrate, and vegetation. Data-collection methods for sites at the three representative reaches and the 55 systematically studied reaches consisted of a field survey of channel and flood-plain geometry and collection of 14 habitat attributes using published protocols or slight modifications. Width/depth and entrenchment ratios along the Meadow-Little Meadow Creek corridor were large and highly variable upstream of Parks Highway and lower and more consistent downstream of Parks Highway. Channel width was strongly correlated with distance, increasing downstream in a log-linear relation. Runs formed the most common habitat type, and instream vegetation dominated the habitat cover types, which collectively covered 53 percent of the channel. Gravel suitable for spawning covered isolated areas along Meadow Creek and about 29 percent of Little Meadow Creek. Broad wetlands were common along both streams. For a comprehensive assessment of small streams in the Mat-Su Valley, critical additional data needs include hydrologic, geologic and geomorphic, and biologic data, in particular the contribution of ground water and lakes to streamflow, water quality, flood plain connectivity, and surficial geology.

Scientific Investigations Report↗
USGS2011

Invasion by nonnative brook trout in Panther Creek, Idaho: Roles of local habitat quality, biotic resistance, and connectivity to source habitats

Theoretical models and empirical evidence suggest that the invasion of nonnative species in freshwaters is facilitated through the interaction of three factors: habitat quality, biotic resistance, and connectivity. We measured variables that represented each factor to determine which were associated with the occurrence of nonnative brook trout Salvelinus fontinalis in Panther Creek, a tributary to the Salmon River, Idaho. Habitat variables included measures of summer and winter temperature, instream cover, and channel size. The abundance of native rainbow trout Oncorhynchus mykiss within sampled sites was used as a measure of biotic resistance. We also considered the connectivity of sample sites to unconfined valley bottoms, which were considered habitats that may serve as sources for the spread of established populations of brook trout. We analyzed the occurrence of small (<150‐mm [fork length]) and large (≥150‐mm) brook trout separately, assuming that the former represents an established invasion while accounting for the higher potential mobility of the latter. The occurrence of small brook trout was strongly associated with the proximity of sites to large, unconstrained valley bottoms, providing evidence that such habitats may serve as sources for the spread of brook trout invasion. Within sites, winter degree‐days and maximum summer temperature were positively associated with the occurrence of small brook trout. The occurrence of large brook trout was not related to any of the variables considered, perhaps due to the difficulty of linking site‐specific habitat factors to larger and more mobile individuals. The abundance of rainbow trout was not conclusively associated with the occurrence of either small or large brook trout, providing little support for the role of biotic resistance. Overall, our results suggest that source connectivity and local habitat characteristics, but not biotic resistance, influence the establishment and spread of nonnative brook trout populations. Further work is needed to confirm that the patterns observed here are relevant to other localities where brook trout have invaded and to understand the mechanisms contributing to the invasion process.

Transactions of the American Fisheries Society↗
USGS1984

Elk and deer diets in old-growth forests in western Washington

Dietary quality and overlap of sympatric Roosevelt elk ( Cervus elaphus roosevelti ) and Columbian black-tailed deer ( Odocoileus hemionus columbianus ) were investigated in old-growth forests of the Hoh Valley, Olympic National Park, Washington. Diets of both cervids were comprised mainly of common old-growth flora, particularly in winter. High dietary overlap suggested competitive interactions for food, especially in winter when forage resources were least available. Predominant forages in fall and winter diets seemed to afford little opportunity for cervids to select different plant parts. Crude protein (CP), in vitro dry matter digestibility (IVDMD), and phosphorus (P) in important forages varied with phenology, but seasonal trends were more pronounced for shrubs and grasses than forbs and trees. CP, IVDMD, and P in cervid diets also varied seasonally and usually in the following ascending order: winter, fall, summer, spring. CP and P appeared to be adequate in diets, but low IVDMD suggested that digestible energy was limited. Few significant differences in seasonal dietary qualities were demonstrated between elk and deer. The collective cervid population (and its habitat) in the Hoh Valley is unmanaged and probably at equilibrium with its food resource, or at ecological carrying capacity. Results are discussed in light of herbivore--habitat interactions at equilibrium densities.

Washington↗
USGS1998

A comparison of small-mammal communities in a desert riparian floodplain

We compared small-mammal communities between inactive floodplain and actively flooded terraces of riparian habitat in the Verde Valley of central Arizona. We used species diversity, abundance, weight of adult males, number of juveniles, number of reproductively active individuals, longevity, residency status, and patterns of microhabitat use to compare the two communities. Although abundances of small mammals tended to be higher in the active floodplain, species diversity was greater in the inactive floodplain. Results were inconsistent with our initial prediction that actively flooded riparian habitat acts as a species source, whereas inactive floodplain acts as a sink or dispersal site for small mammals. Within each habitat type, we found evidence of significant microhabitat separation among the three most abundant small-mammal species (Peromyscus boylii, P. eremicus, and Neotoma albigula). Percent cover by annual and perennial grasses and shrubs, substrate, and frequency of shrubs, trees, and debris were significant determinants of small-mammal distribution within a habitat type. We found that the three most abundant species selected a nonrandom subset of available habitat. Nonrandom use of habitat and microhabitat separation were the two most important mechanisms structuring small-mammal communities in riparian habitat of central Arizona.

Journal of Mammalogy↗
USGS2011

Distribution and habitat associations of breeding secretive marsh birds in Louisiana's Mississippi Alluvial Valley

Populations of many North American secretive marsh birds (SMBs) have declined in recent decades, partially as a function of wetland loss. Protecting and restoring appropriate habitat for these species is contingent upon understanding the habitat features they utilize. We investigated breeding distributions of SMBs in northeast Louisiana at 118 wetlands in 2007 and 2008 and modeled species occupancy (psi) as a function of habitat variables measured at local (<= 100 m) and landscape (<= 1 km) scales. Common Moorhens (Gallinula chloropus), Least Bitterns (Ixobrychus exilis), and Purple Gallinules (Porphyrula martinica) were the most commonly detected species, whereas breeding King Rails (Rallus elegans) and American Coots (Fulica americana) were rare. Local habitat features consistently played a greater role in predicting psi than landscape features for the three most common species. The proportion of local wetland area dominated by robust emergent vegetation (i.e., Typha spp. and Zizaniopsis miliacea) positively influenced psi for all species, while other wetland vegetation types tended to have a minimal or negative effect. Our results suggest the habitat characteristics preferred by breeding SMBs differ from those used by migrating shorebirds and wintering waterfowl and management and restoration objectives for those species may be inadequate for enhancing SMB habitat.

Louisana↗
USGS2009

Impacts of forest fragmentation on species richness: A hierarchical approach to community modelling

1. Species richness is often used as a tool for prioritizing conservation action. One method for predicting richness and other summaries of community structure is to develop species-specific models of occurrence probability based on habitat or landscape characteristics. However, this approach can be challenging for rare or elusive species for which survey data are often sparse. 2. Recent developments have allowed for improved inference about community structure based on species-specific models of occurrence probability, integrated within a hierarchical modelling framework. This framework offers advantages to inference about species richness over typical approaches by accounting for both species-level effects and the aggregated effects of landscape composition on a community as a whole, thus leading to increased precision in estimates of species richness by improving occupancy estimates for all species, including those that were observed infrequently. 3. We developed a hierarchical model to assess the community response of breeding birds in the Hudson River Valley, New York, to habitat fragmentation and analysed the model using a Bayesian approach. 4. The model was designed to estimate species-specific occurrence and the effects of fragment area and edge (as measured through the perimeter and the perimeter/area ratio, P/A), while accounting for imperfect detection of species. 5. We used the fitted model to make predictions of species richness within forest fragments of variable morphology. The model revealed that species richness of the observed bird community was maximized in small forest fragments with a high P/A. However, the number of forest interior species, a subset of the community with high conservation value, was maximized in large fragments with low P/A. 6. Synthesis and applications. Our results demonstrate the importance of understanding the responses of both individual, and groups of species, to environmental heterogeneity while illustrating the utility of hierarchical models for inference about species richness for conservation. This framework can be used to investigate the impacts of land-use change and fragmentation on species or assemblage richness, and to further understand trade-offs in species-specific occupancy probabilities associated with landscape variability.

New York↗
USGS2005

Determining forage availability and use patterns for bison in the Hayden Valley of Yellowstone National Park

In our original Proposal, we identified 4 objectives: 1. Delineate seasonal forage use patterns by bison in the Hayden Valley; 2. Determine long and short term effects of ungulate foraging on vegetation in the Hayden Valley; 3. Determine efficacy of vegetation monitoring approaches; 4. Estimate annual production and standing crop available during non-growing seasons for herbaceous and shrub layers in major habitat types in the Hayden Valley. Our efforts to describe forage use by bison focused on assessing finer scale habitat use is a core summer range for bison in YNP. We also collected information on bison food habits and forage quality to begin to explain the &ldquo;whys&rdquo; of bison distribution. Short-term impacts of bison forage utilization were addressed by comparing standing biomass in plots protected from grazing with plots exposed to grazing. Historical data were not available to directly address long-term effects of ungulate foraging in the Hayden Valley, but we were able to indirectly assess some aspects of this question by determining the frequency of repeat grazing over a 3-year period and the rate at which trees along the margins of the Hayden Valley were being killed by bison rubbing The third objective, determining the relative efficacy of different vegetation monitoring approaches, was accomplished by comparing estimates of standing biomass and biomas: utilization obtained via conventional exclosure techniques with estimates based on remote sensing techniques (ground-based and satellite-borne multi-spectral radiometry|[MSR]). We addressed efficacy in terms of precision and accuracy of estimates, reliability, and logistical costs at different coverage scales. The fourth objective, estimation of forage available for ungulates in the Hayden Valley, was achieved using conventional exclosure methodology and remote sensing. We were able to estimate herbaceous biomass production during 3 different years. Exclosures allowed us to estimated changes instanding crop of herbaceous vegetation at the plant community (conventional cover types, moisture plant growth form groups, and communities defined by dominant graminoids) and catena (a repeating sequence of communities tied to landscape physiognomy) scales. We developed empirical approaches that allowed us to estimate standing biomass of herbaceous plants from reflectance data obtained from ground-based and satellite-borne multi-spectral radiometry (MSR) units. We demonstrated the potential to estimate biomass of shrubs using the same approaches. We did not have time and resources to complete vegetation maps that would optimize estimates from remote sources, but we have outlined procedures that can be followed in the future to obtain biomass estimates at the landscape scale.

Wyoming↗
USGS1998

Shorebird use of managed wetlands in the Mississippi Alluvial Valley

We assessed shorebird densities on managed wetland habitats during fall and winter within the primarily agricultural landscape of the Mississippi Alluvial Valley. From November through March, shorebird densities were greater on soybean fields than on rice or moist-soil fields. Killdeer (Charadrius vociferus) and Common Snipe (Gallinago gallinago) were common throughout winter, whereas Yellowlegs (Tringa spp.) and ?peep? sandpipers (Calidris spp.) were present but less abundant. During fall, Dowitchers (Limnodromus spp.), Pectoral Sandpipers (Calidris melanotos), Killdeer, and peep sandpipers were the most abundant species on managed shorebird habitat units. Although shorebird densities were consistently greater on habitats managed by drawing down existing water, we were unable to detect a significant difference in densities from areas managed by flooding previously dry habitat.

American Midland Naturalist↗
USGS2012

Summary of bird-survey and banding results at W.L. Finley National Wildlife Refuge, 1998-2008

With some of the best remaining examples of oak habitats in the Willamette Valley, the Willamette Valley National Wildlife Refuge Complex (WVNWRC) has been implementing restoration efforts to reverse the successional trend towards Douglas-fir and maple that is threatening existing oak woodlands. The restoration work has been considered a model for other public and private efforts within the Willamette Valley, and has been showcased through the Oregon Oak Communities Working Group (http://www.oregonoaks.org). Although many oak restoration projects have been initiated over the last several years, and grant recipients typically identify wildlife species that are likely to benefit from their project, measures of success have not included the actual response of wildlife, such as a change in the probability of species occurrence or abundance. Monitoring in the WVNWRC has so far been limited to vegetative and structural changes within the plant community. Hagar and Stern (2001) identified bird species occurring in Willamette Valley oak woodlands that might be expected to benefit from such restoration efforts, including an endemic subspecies of the White-breasted Nuthatch (see Appendix 1 for scientific names of bird and plant species listed in this document), and the Acorn Woodpecker, both of which are species of concern in Oregon. However, empirical data documenting responses of bird assemblages to restoration actions are needed. The goal of this study was to document the effects of a restoration project in an Oregon White Oak woodland on Pigeon Butte in the W.L. Finley National Wildlife Refuge. Restoration treatments on Pigeon Butte include the removal of shade-tolerant tree species (primarily big-leaf maple and Douglas-fir) to reduce competition with oak trees and to return the stand to a more open structure. The objectives of this ongoing study are to compare abundance, survival, and productivity of diurnal songbird species before and after application of these restoration treatments. Monitoring these vital rates will provide crucial information about the effects of management on survival and productivity (DeSante and Rosenberg, 1998). Therefore, a constant-effort mist-netting project was continued in 2007 and 2008 that had previously collected songbird demographic data at Pigeon Butte from 1998 to 2002. Point-count surveys were conducted in the woodland to build on historical data available for the site (Anderson, 1970; Hagar and Stern, 2001). The data reported here represent 5 years of point count surveys and 6 years of banding before restoration treatment, but only one post-treatment sampling season. Continued monitoring of the bird population is recommended to determine both short-term effects and long-term trends following the habitat alterations that result from restoration treatment.

Oregon↗