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Results for “Wilson Bulletin”

Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

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At least 217 records · Page 12Linked to original sources
USGS1994

Dynamics of ovarian follicles in breeding ducks

I quantified ovarian rapid follicle growth (RFG) and regression of postovulatory follicles of Northern Pintails ( Anas acuta ), American Wigeon ( A. americana ), and Lesser Scaup ( Aythya affinis ) by a method that accounted for within-day variation in follicle size. Objective methods for identifying onset of RFG also are presented; this is crucial for accurate classification of breeding status. Duration of RFG was estimated as 4.2, 5.1, and 5.0 days for pintails, wigeon, and scaup, respectively; these are shorter than previously reported. Diameters of follicles at the beginning of RFG were estimated to be 8.2, 6.9, and 7.9 mm for pintails, wigeon, and scaup, respectively. For all species, RFG was linear, using follicle diameters, and exponential, using dry masses. Models of RFG and postovulatory follicle regression have practical value for calculating nest initiation dates, number of developing follicles, clutch size, renesting intervals, and daily energy and nutrient commitment to reproduction of collected breeding females.

Alaska↗
USGS1999

Juvenile Marbled Murrelet nurseries and the productivity index

Late summer counts of juveniles at sea are used as an index of Marbled Murrelet ( Brachyramphus marmoratus ) reproductive success, but little is known about juvenile dispersal or habitat use. Further, it is not known whether these counts accurately reflect absolute breeding success. To address these questions we conducted five boat surveys for Marbled Murrelets and Pigeon Guillemots ( Cepphus columba ) in Kachemak Bay, Alaska between 7-24 August 1996. Juvenile murrelet distribution in the bay was patchy, and we identified a juvenile Marbled Murrelet 'nursery' area in the outer bay. Fifty-three of 61 juvenile murrelets were in this area, whereas after-hatch-year (AHY) murrelets were dispersed throughout the bay, as were juvenile and AHY Pigeon Guillemots. The murrelet nursery was characterized by water inside of or at the edge of a 20 m deep contour, semi-protected seas, productive waters, and a large bed of Nereocystis kelp. Juveniles comprised 16.1% of all murrelets and 24.8% of all guillemots observed at sea. These data suggest a maximum reproductive success of 0.32 chicks/pair if all AHY murrelets were breeding and 0.46 chicks/pair if only 70% of AHY murrelets were breeding. For guillemots, maximum productivity estimated from at-sea counts was 0.50 chicks/pair if all AHY were breeding and 0.71 chicks/pair if only 70% were breeding. The guillemot estimate was similar to that obtained by concurrent studies at nine guillemot colonies in the bay (0.56 chicks/pair). These results suggest that at sea surveys in late summer provide a reasonable index of local productivity for nearshore alcids. Further, if murrelet nursery areas can be found, at sea counts may provide a valid measure of absolute productivity.

Alaska↗
USGS1989

Nest habitat use of Rio Grande wild turkeys

Nest habitat use of Rio Grande Wild Turkeys ( Meleagris gallopavo intermedia ) was studied along the South Platte River in northeast Colorado in 1986-87. Thirty-three of 35 nests were in riparian habitats. Nests were either in western snowberry ( Symphoricarpos occidentalis ) (67%) or mixed forbs and grasses (33%). Early season nests were more likely to be in snowberry than late season nests. Nest sites were characterized by greater overstory canopy cover, more shrubs, fewer grasses, and greater understory cover and height than surrounding areas. These areas had more shrubs, fewer large trees, and greater understory cover and height than riparian habitats throughout the study area. Phenology of understory vegetation and the effect of such vegetation on nest predation may influence temporal patterns of nest habitat use.

The Wilson Bulletin↗
USGS1996

Food availability and feeding preferences of breeding fulvous whistling-ducks in Louisiana ricefields

Expansion of the breeding distribution of the Fulvous whistling-duck ( Dendrocygna bicolor ) into the southeastern United States after the mid-1800s coincided with the establishment of rice ( Oryza sativa) cultures in Texas, Louisiana, and Florida. In southern Louisiana, where approximately 80% of rice is aerially seeded in water, Fulvous whistling-ducks are suspected of feeding extensively on planted rice and are considered a nuisance. To determine the extent of rice utilization by ducks nesting in southwestern Louisiana, we estimated food availability in ricefields and assessed feeding preferences. We also examined effects of sex and stage of reproduction on food selection. Feeding sites in Louisiana ricefields that were tilled and flooded in preparation for spring planting, contained abundant foods (mean ± SE = 109.0 ± 18.0 g/m2, especially seeds of moist soil plants such as signalgrass ( Brachiaria extensa ), beakrush ( Rhynchospora sp.), and flatsedge ( Cyperus iria ). Diets of males and females were similar (P = 0.080), but varied through the reproductive cycle (P = 0.008). Consumption of plant material was slightly reduced during the period of rapid ovarian follicle growth in females; however, ingestion of animal foods never exceeded 4%. Fulvous whistling-ducks exhibited feeding preferences (P < 0.001) with aquatic earthworms (Oligochaeta) and wild millet seeds ( Echinochloa sp.) being preferred over other food taxa. Rice made up <4% of the diet and was selected in proportion to its availability before and during period of rapid follicle development. Almost 25% of the diet of incubating females consisted of rice; however, we concluded that crop depredation by Fulvous whistling-ducks (≤0.1%) was of minor importance relative to other potential sources of crop loss. Indeed, use of ricefields by whistling-ducks may actually benefit farmers if ingestion of seeds of undesirable plants reduces the need for costly herbicide treatments.

Louisiana↗
USGS1990

Diurnal time-activity budgets of wintering canvasbacks in Louisiana

We determined diurnal time-activity budgets of Canvasbacks ( Aythya valisineria ) at Catahoula Lake and at the Mississippi River Delta, Louisiana, from December 1987 to March 1988. Canvasback feeding, resting, locomotory, and comfort activities varied by month and location with a month-location interaction. Moreover, the percentage of time spent feeding varied by sex with a month-sex interaction. Study site differences in the time- activity budgets of wintering Canvasbacks may be related to characteristics of their foods, foraging mode, disturbance level, and physical features of habitats at the two study sites. Canvasbacks wintering in Louisiana generally spent less time feeding and more time resting during the day than they did in Mississippi or coastal South Carolina. Levels of agonistic behavior were lower than those observed in South Carolina. We found no evidence of male dominance of female Canvasbacks in Louisiana.

Louisiana↗
USGS1975

Fertility of eggs produced on territories of vasectomized red-winged blackbirds

Six male Red-winged Blackbirds scattered throughout 2 marshes were vasectomized in 1971, and their females began laying infertile clutches in 5 days. However, of 39 clutches on their territories, 27 (69%) were fertile. In 1972, 30, 50, and 100% of the males in 3 small isolated marshes were vasectomized, and 44, 33, and 12% of the clutches on their territories were fertile, respectively. All clutches were fertile in a fourth marsh where /// all males were sham-operated. All clutches checked were fertile on territories of fertile males adjacent to sterilized males. During the 2 years there were only 4 partially fertile clutches, 2 each on vasectomized and fertile males' territories. Examination of reproductive tracts of female Red-wings from other marshes showed that sperm retained from copulation were abundant during nest-building or egg-laying but had dropped to a few by hatching. In vasectomy studies, vasectomized males whose territories were the farthest from fertile males had the lowest percentage of fertile clutches. This and other evidence indicated that fertile clutches on territories of vasectomized males may have been due to females being promiscuous with fertile males. The occurrence of fertile clutches on territories of vasectomized males indicates that sterilizing some of the males in a population (as in a chemosterilant program) would not result in a proportional decrease in fertile clutches. However, the decreases achieved (up to 88%), and the probability of better results in an actual program, indicate that male chemosterilization would be a feasible means of reducing Red-wing populations.

Colorado↗
USGS1970

Hydrogeologic data for the lower Housatonic River basin, Connecticut

This report contains hydrologic and geologic data collected for an investigation of the lower Housatonic River basin by the U.S. Geological Survey in financial cooperation with the Connecticut Water Resources Commission. The report also summarizes data that are available in other publications. The towns within the 557 square mile area of the basin in western Connecticut include all of Beacon Falls, Middlebury, Naugatuck, Oxford, Seymour, Thomaston, Waterbury, Watertown, and Woodbury; and parts of Ansonia, Bethany, Bethlehem, Bristol, Burlington, Cheshire, Derby, Easton, Goshen, Narwinton, Litchfield, Milford, Monroe, Morris, New Hartford, Newtown, Norfolk, Orange, Plymouth, Prospect, Roxbury, Shelton, Southbury, Stratford, Torrington, Trumbull, Washington, Winchester, Wolcott, and Woodbridge. The factual information on the following pages was the basis for a companion interpretive report, Connecticut Water Resources Bulletin No. 19 (Wilson, W. E., and others, in preparation, 1970). The basic-data report can be used alone for detailed information needed in planning water resources development at specific sites or it can be used to supplement the interpretive report. Data were collected for this investigation from 1965 to 1967. Water levels measured in wells as part of this investigation were published in Connecticut Water Resources Bulletin No. 7 (Meikle and Baker, 1965) and No. 13 (Meikle, 1967) with water-level data from other wells throughout the State. Publications containing relevant ground-water information are listed on page those concerned with streamflow are on page 5 and those on quality of water, are on page 6. The locations of sites at which data were collected are shown on plate A in the back pocket of this report. Data presented here were collected by the U.S. Geological Survey unless otherwise noted.

Connecticut↗
USGS2018

River otter distribution in Nebraska

The river otter ( Lontra canadensis ) was extirpated from Nebraska, USA, in the early 1900s and reintroduced starting in 1986. Information is needed regarding the distribution of river otters in Nebraska before decisions can be made regarding its conservation status. Understanding distribution of a species is critically important for effective management. We investigated river otter distribution in Nebraska with occupancy modeling and maximum entropy (Maxent) modeling using 190 otter sign observations on Nebraska's navigable rivers and 380 historical otter records from November 1977 to April 2014. Both methods identified the Platte River, Elkhorn River, central and eastern Niobrara River, and southern Loup River system as core areas within the distribution of otters in Nebraska. The Maxent model provided more liberal estimates of site occupancy and identified some smaller rivers as being within the distribution of otters in Nebraska, which were not identified using occupancy modeling. We recommend that multiple data sets and analysis methods be used to estimate species distribution because this allows for the broadest geographical coverage and decreases the likelihood of overlooking areas with fewer animal records. If further reintroduction efforts or translocation efforts are to take place in the future, we recommend focusing on areas with high modeled occupancy but few historical and survey records

Nebraska↗
USGS1995

Factors influencing the height of Hawaiian lava fountains: implications for the use of fountain height as an indicator of magma gas content

The heights of lava fountains formed in Hawaiian-style eruptions are controlled by magma gas content, volume flux and the amounts of lava re-entrainment and gas bubble coalescence. Theoretical models of lava fountaining are used to analyse data on lava fountain height variations collected during the 1983–1986 Pu'u 'O'o vent of Kilauea volcano, Hawaii. The results show that the variable fountain heights can be largely explained by the impact of variations in volume flux and amount of lava re-entrainment on erupting magmas with a constant gas content of ∼0.32 wt.% H 2 O. However, the gas content of the magma apparently declined by ∼0.05 wt.% during the last 10 episodes of the eruption series and this decline is attributed to more extensive pre-eruption degassing due to a shallowing of the sub-vent feeder dike. It is concluded that variations in lava fountain height cannot be simply interpreted as variations in gas content, as has previously been suggested, but that fountain height can still be a useful guide to minimum gas contents. Where sufficient data are available on eruptive volume fluxes and extent of lava entrainment, greatly improved estimates can be made of magma gas content from lava fountain height.

Bulletin of Volcanology↗
USGS2021

From anecdotes to quantification: Advances in characterizing volcanic eruption impacts on the built environment

Over the past 20 years, our understanding of volcanic eruption impacts on the built environment has transformed from being primarily observational with small datasets to one grounded in field investigations, laboratory experiments, and quantitative modeling, with an emphasis on stakeholder collaboration and co-creation. Here, we summarize key advances and knowledge gaps of impacts across volcanic hazards and built environment types from the past 20 + years. Studies have concentrated on impacts from tephra fall (ash) and to buildings, with less examination of other hazards’ impacts to critical infrastructure. As we look to the next decade, we speculate on likely research directions, including the increasing role of new technologies, higher resolution modeling, transdisciplinary collaborations, and evidence-based mitigative solutions.

Bulletin of Volcanology↗
USGS2011

Cytochrome P4501A biomarker indication of the timeline of chronic exposure of Barrow’s goldeneyes to residual Exxon Valdez oil

We examined hepatic EROD activity, as an indicator of CYP1A induction, in Barrow’s goldeneyes captured in areas oiled during the 1989 Exxon Valdez spill and those from nearby unoiled areas. We found that average EROD activity differed between areas during 2005, although the magnitude of the difference was reduced relative to a previous study from 1996/1997, and we found that areas did not differ by 2009. Similarly, we found that the proportion of individuals captured from oiled areas with elevated EROD activity (⩾2 times unoiled average) declined from 41% in winter 1996/1997 to 10% in 2005 and 15% in 2009. This work adds to a body of literature describing the timelines over which vertebrates were exposed to residual Exxon Valdez oil and indicates that, for Barrow’s goldeneyes in Prince William Sound, exposure persisted for many years with evidence of substantially reduced exposure by 2 decades after the spill.

Alaska↗
USGS2005

Attitudes of Vermont dairy farmers regarding adoption of management practices for grassland songbirds

In the northeastern United States, most populations of grassland songbirds occur on private lands. However, little information exists about the attitudes of farmers toward habitat management for this guild. To address this information gap, we surveyed 131 dairy farmers in Vermont's Champlain Valley to assess current hayfield management practices and farmers' willingness to adopt more “bird-friendly” practices. Our results showed a clear trend toward earlier and more frequent hayfield cuts. Farmers indicated they have little flexibility to alter the timing of their cuts on most of their land. However, many farmers (49%) indicated a willingness to adopt alternative management practices on at least a small portion of their land. Combined with the fact that many farmers characterized parts of their land as “wasteland,” or economically unproductive land, this result suggests that some leeway exists for increasing songbird habitat quality on at least portions of dairy farms. Although significant differences existed in the amount of land for which farmers were willing to adopt alternative management based on herd size, acreage, and experience, the directionality of these relationships could not be established except tentatively for herd size, in which case it appeared that farmers with smaller herds were more likely to dedicate a greater percentage of their land to alternative management. The results of this study likely have relevance to dairy farms throughout the northern-tier dairy states. Given the increasing trend for agricultural land to be converted into housing, we recommend that extension and education efforts target farmers with large hayfield acreages, encouraging the maintenance of high-quality habitat for grassland songbirds.

Vermont↗
USGS2006

The role of the Wetland Reserve Program in conservation efforts in the Mississippi River Alluvial Valley

The Mississippi River Alluvial Valley includes the floodplain of the Mississippi River from Cairo, Illinois, USA, to the Gulf of Mexico. Originally this region supported about 10 million ha of bottomland hardwood forests, but only about 2.8 million ha remain today. Furthermore, most of the remaining bottomland forest is highly fragmented with altered hydrologic processes. During the 1990s landscape-scale conservation planning efforts were initiated for migratory birds and the threatened Louisiana black bear ( Ursus americanus luteolus ). These plans call for large-scale reforestation and restoration efforts in the region, particularly on private lands. In 1990 the Food, Agriculture, Conservation and Trade Act authorized the Wetlands Reserve Program (WRP). The WRP is a voluntary program administered by the United States Department of Agriculture that provides eligible landowners with financial incentives to restore wetlands and retire marginal farmlands from agricultural production. As of 30 September 2005, over 275,700 ha have been enrolled in the program in the Mississippi River Alluvial Valley, with the greatest concentration in Louisiana, Arkansas, and Mississippi, USA. Hydrologic restoration is common on most sites, with open-water wetlands, such as moist-soil units and sloughs, constituting up to 30% of a given tract. Over 33,200 ha of open-water wetlands have been created, potentially providing over 115,000,000 duck-use days. Twenty-three of 87 forest-bird conservation areas have met or exceed core habitat goals for migratory songbirds and another 24 have met minimum area requirements. The WRP played an integral role in the fulfillment of these goals. Although some landscape goals have been attained, the young age of the program and forest stands, and the lack of monitoring, has limited evaluations of the program's impact on wildlife populations.

Mississippi River Alluvial Valley↗