495 research outputs found
Secretive Marsh Bird Species Co-Occurrences and Habitat Associations Across the Midwest, USA
Because secretive marsh birds are difficult to detect, population status and habitat use for these birds are not well known. We conducted repeated surveys for secretive marsh birds across 264 sites in the Upper Mississippi River and Great Lakes Joint Venture region to estimate abundance, occupancy, and detection probabilities during the 2008 and 2009 breeding seasons. We identified species groups based on observed species co-occurrences. Two species, least bittern Ixobrychus exilis and American bittern Botaurus lentiginosus, co-occurred with other species less often than expected by chance, and two species groups, rails (Virginia rail Rallus limicola and sora Porzana carolina) and openwater birds (pied-billed grebe Podilymbus podiceps, common moorhen Gallinula chloropus, and American coot Fulica americana; coots were only surveyed in 2009), co-occurred more often than expected by chance. These groupings were consistent between years. We then estimated the relation of these species and groups to landscape and local site characteristics by using zero-inflated abundance models that accounted for incomplete detection. At the landscape level (5-km radius), the amount of emergent herbaceous wetland was positively associated with least bittern occupancy, whereas the amount of woody wetland was negatively associated with least bittern, rail, and open-water bird occupancy. At the local level, habitat variables that were associated with abundance were not consistent among groups or between years, with the exception that both least bitterns and open-water birds had a strong positive association between abundance and water–vegetation interspersion. Land managers interested in marsh bird management or conservation may want to consider focusing efforts on landscapes with high amounts of emergent herbaceous wetland and low amounts of woody wetland, and managing for high amounts of water–vegetation interspersion within the wetland
Autumn Migration of Mississippi Flyway Mallards as Determined by Satellite Telemetry
We used satellite telemetry to study autumn migration timing, routes, stopover duration, and final destinations of mallards Anas platyrhynchos captured the previous spring in Arkansas from 2004 to 2007. Of those mallards that still had functioning transmitters on September 15 (n = 55), the average date when autumn migration began was October 23 (SE = 2.62 d; range = September 17–December 7). For those mallards that stopped for .1 d during migration, the average stopover length was 15.4 d (SE = 1.47 d). Ten mallards migrated nonstop to wintering sites. The eastern Dakotas were a heavily utilized stopover area. The total distance migrated per mallard averaged 1,407 km (SE = 89.55 km; range = 142–2,947 km). The average time spent on migration per individual between September 15 and December 15 was 27 d (SE = 2.88 d; range = 2–84 d). The state where most mallards were located on December 15 was Missouri (11) followed by Arkansas (8), while 5 mallards were still in Canada, and only 8 of 43 females and 0 of 10 males were present in Arkansas. The eastern Dakotas are a heavily utilized migration stopover for midcontinent mallards that may require more attention for migration habitat management. The reasons for so few mallards, especially male mallards, returning to Arkansas the following year deserves further research
Bioenergetics Of Breeding House Sparrows
Between April, 1981 and July, 1983, I collected 563 (211 male, 352 female) house sparrows (Passer domesticus) around London, Ontario, weighed their nutrient reserves (protein, fat, calcium) and determined their food habits, to see if nutrient reserves proximately control clutch size in this species. Daily energy demands during egg production were evaluated by analyzing changes in nutrient reserves. Captive house sparrows were studied to determine if stored fat was deposited in eggs.;The proportion of males and females that consumed high-protein foods varied with the seasonal availability of insects. Insect use was low until egg laying but then increased and remained high thereafter. Insect consumption by males and females was similar throughout breeding. The porportion of males and females that ate calciferous material was constant (low) until egg production began. Then most females, but few males, consumed claciferous materials. After laying, female consumption of calciferous materials declined and again equaled males.;Before egg production began, males used protein and fat but not calcium reserves; protein and fat reserves of females were constant but calcium was accumulated. Because the proportion of females that consumed calciferous materials did not change during prereproduction, females must have accumulated calcium through increased retention of calcium from their normal diet. After egg production began, male nutrient reserves remained constant through postreproduction. Female protein and calcium reserves declined linearly during egg production; fat reserves, however, increased while 50% of the fat in a clutch was being allocated, and declined rapidly thereafter. The use of protein and fat reserves was independent of clutch size as all postlaying females had at least enough protein and fat to build an additional egg. Protein and calcium reserves of postlaying females remained constant but fat increased.;Maximum daily energy required for egg production was, at most, 50% of basal metabolic rate. Fat ingested by captive house sparrows was deposited daily in the developing follicles and fat not put into follicles went to fat depots, which were used rapidly. I conclude that, although female house sparrows do use nutrient reserves during egg laying, their clutch size is not controlled thereby
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DEVELOPMENT OF REMOTE HANFORD CONNECTOR GASKET REPLACEMENT TOOLING FOR THE SAVANNAH RIVER SITE'S DEFENSE WASTE PROCESSING FACILITY
The Savannah River Site's (SRS) Defense Waste Processing Facility (DWPF) requested development of tooling for remote replacement of gaskets in mechanical Hanford connectors. The facility has compressed air supply, two master-slave manipulators (MSM's) and a lightweight robotic arm for operation of the remote tools. The Savannah River National Laboratory (SRNL) developed and tested multiple tools to perform the gasket replacement tasks. Separate pneumatic snap-ring removal tools that use the connector skirt as a reaction surface were developed for removal of the snap ring and spent gasket on both vertical and horizontal Hanford connectors. A pneumatic tool that clamps and centers on the jumper pipe ID was developed to simultaneously install the new gasket and snap ring. A pneumatic snap-ring-loading tool was developed that compresses the snap ring and places it in a groove in the installation tool. All of the tools are located on a custom work table with a pneumatic valve station that directs compressed air to the desired tool and vents the tools as needed. The entire system has been successfully tested using MSM's to manipulate the various tools. Deployment of the entire system is expected during FY08. The Hanford connector gasket replacement tooling has been successfully tested using MSM's to manipulate the various tools. Nitric acid is used in many of the decontamination processes performed in the REDC, where the tooling will be deployed. Although most of the tool components were fabricated/purchased with nitric acid and radioactive service in mind, some of the prototype parts must be replaced with parts that are more compatible with nitric acid/radioactive service. Several modifications to the various tools are needed to facilitate maintenance and replacement of failed components. Development of installation tools for replacement of 1-inch, 2-inch and multi-hole gaskets is being considered. Deployment of the existing system in the DWPF REDC is expected during FY08
WOOD THRUSH MOVEMENTS AND HABITAT USE: EFFECTS OF FOREST MANAGEMENT FOR RED-COCKADED WOODPECKERS
We monitored adult and juvenile breeding-season movements and habitat use of radio-tagged Wood Thrushes (Hylocichla mustelina) at the Piedmont National Wildlife Refuge, central Georgia, USA. We investigated the effects that management for Red-cockaded Woodpeckers (Picoides borealis), thinning and burning \u3e30 year old loblolly pine (Pinus taeda) habitat, had on Wood Thrushes, a ground-foraging and midstory-nesting species. Adult Wood Thrush pairs regularly moved long distances between nesting attempts (range 1 to 17,388 m). The only experimental effect we found on adult movements was a decrease in weekly emigration rates (AP) from thinned and burned compartments after silvicultural management. Adult males preferred riparian hardwoods with sparse to moderate cover and those preferences increased following management. Juveniles remained near their nest site (x = 177 m, SE = 113) for an average 24 days (SE = 6.3), and then dispersed a mean 2,189 m (SE = 342). Before dispersal, juveniles preferred upland hardwood-pine mixed habitat (P \u3c 0.05) with moderate overstory cover (P \u3c 0.05). We found no management effects on dispersal distances or predispersal habitat use. However, juveniles from thinned and burned compartments dispersed to hardwood habitats with dense cover, whereas birds from control compartments dispersed to pine-dominated habitats with sparse cover. All juveniles dispersed to areas with habitat similar to what they used before dispersal. Small-scale thinning and burning for Red-cockaded Woodpeckers may have had little effect on Wood Thrush habitat use and movements because typical movements were often larger than the scale (stand or compartment) targeted for management.
Monitoreamos con radio-telemetria los movimientos y el uso de habitat durante la 6poca reproductiva de adultos y juveniles de Hylocichla mustelina en el Refugio Nacional de Vida Silvestre Piedmont, en Georgia central, EEUU. Investigamos los efectos que tiene el manejo del bosque (entresaca y quema de hibitat de Pinus taeda con mas de 30 anios de edad) orientado a la conservaci6n de Picoides borealis sobre H. mustelina, una especie que se alimenta en el suelo y que nidifica a media altura del bosque. Las parejas adultas de H. mustelina por lo general se movieron largas distancias entre los intentos de nidificaci6n (rango 1 a 17,388 m). El uanico efecto experimental que encontramos en los movimientos de adultos fue una disminuci6n en las tasas semanales de emigraci6n (T) desde los sectores entresacados y quemados luego del manejo silvicultural. Los machos adultos prefirieron los bosques riberefios con poca a moderada cobertura, y estas preferencias incrementaron luego del manejo. Los juveniles permanecieron cercanos al sitio de nidificaci6n (x = 177 m, ES = 113) por un promedio de 24 dias (ES = 6.3) y luego se dispersaron una media de 2,189 m (ES = 342). Antes de la dispersi6n los juveniles prefirieron habitat no-ribereiio mixto de bosque y pino (P \u3c 0.05) con moderada cobertura del dosel (P \u3c 0.05). No encontramo
WOOD THRUSH MOVEMENTS AND HABITAT USE: EFFECTS OF FOREST MANAGEMENT FOR RED-COCKADED WOODPECKERS
We monitored adult and juvenile breeding-season movements and habitat use of radio-tagged Wood Thrushes (Hylocichla mustelina) at the Piedmont National Wildlife Refuge, central Georgia, USA. We investigated the effects that management for Red-cockaded Woodpeckers (Picoides borealis), thinning and burning \u3e30 year old loblolly pine (Pinus taeda) habitat, had on Wood Thrushes, a ground-foraging and midstory-nesting species. Adult Wood Thrush pairs regularly moved long distances between nesting attempts (range 1 to 17,388 m). The only experimental effect we found on adult movements was a decrease in weekly emigration rates (AP) from thinned and burned compartments after silvicultural management. Adult males preferred riparian hardwoods with sparse to moderate cover and those preferences increased following management. Juveniles remained near their nest site (x = 177 m, SE = 113) for an average 24 days (SE = 6.3), and then dispersed a mean 2,189 m (SE = 342). Before dispersal, juveniles preferred upland hardwood-pine mixed habitat (P \u3c 0.05) with moderate overstory cover (P \u3c 0.05). We found no management effects on dispersal distances or predispersal habitat use. However, juveniles from thinned and burned compartments dispersed to hardwood habitats with dense cover, whereas birds from control compartments dispersed to pine-dominated habitats with sparse cover. All juveniles dispersed to areas with habitat similar to what they used before dispersal. Small-scale thinning and burning for Red-cockaded Woodpeckers may have had little effect on Wood Thrush habitat use and movements because typical movements were often larger than the scale (stand or compartment) targeted for management.
Monitoreamos con radio-telemetria los movimientos y el uso de habitat durante la 6poca reproductiva de adultos y juveniles de Hylocichla mustelina en el Refugio Nacional de Vida Silvestre Piedmont, en Georgia central, EEUU. Investigamos los efectos que tiene el manejo del bosque (entresaca y quema de hibitat de Pinus taeda con mas de 30 anios de edad) orientado a la conservaci6n de Picoides borealis sobre H. mustelina, una especie que se alimenta en el suelo y que nidifica a media altura del bosque. Las parejas adultas de H. mustelina por lo general se movieron largas distancias entre los intentos de nidificaci6n (rango 1 a 17,388 m). El uanico efecto experimental que encontramos en los movimientos de adultos fue una disminuci6n en las tasas semanales de emigraci6n (T) desde los sectores entresacados y quemados luego del manejo silvicultural. Los machos adultos prefirieron los bosques riberefios con poca a moderada cobertura, y estas preferencias incrementaron luego del manejo. Los juveniles permanecieron cercanos al sitio de nidificaci6n (x = 177 m, ES = 113) por un promedio de 24 dias (ES = 6.3) y luego se dispersaron una media de 2,189 m (ES = 342). Antes de la dispersi6n los juveniles prefirieron habitat no-ribereiio mixto de bosque y pino (P \u3c 0.05) con moderada cobertura del dosel (P \u3c 0.05). No encontramo
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TESTING OF TMR SAND MANTIS FINAL REPORT
Screening tests of Sand Mantis candidate materials selected for erosion resistance have been completed. The results of this testing identified that over a relatively short period of operation (<1 hour), measurable erosion will occur in each of the candidate zoom tube materials given equal operating exposure. Additionally, this testing has shown that erosion of the rubber discharge hose directly downstream of the vehicle could be expected to limit the service life of the discharge hose. On the basis of these test results, SRNL recommends the following; {lg_bullet} redesign of critical system components (e.g., zoom tube, discharge hose) should be conducted to improve system characteristics relative to erosion and capitalize on the results of this testing, {lg_bullet} continued efforts to deploy the Sand Mantis should include testing to better define and optimize operating parameters, and gain an understanding of system dynamics, {lg_bullet} discontinue wear testing with the selected materials pending redesign of critical system components (1st recommendation) and inclusion of other candidate materials. The final selection of additional candidate materials should be made following design changes, but might include a Stellite alloy or zirconia
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242-16H 2H EVAPORATOR POT SAMPLING FINAL REPORT
Due to the materials that are processed through 2H Evaporator, scale is constantly being deposited on the surfaces of the evaporator pot. In order to meet the requirements of the Nuclear Criticality Safety Analysis/Evaluation (NCSA/NCSE) for 2H Evaporator, inspections of the pot are performed to determine the extent of scaling. Once the volume of scale reaches a certain threshold, the pot must be chemically cleaned to remove the scale. Prior to cleaning the pot, samples of the scale are obtained to determine the concentration of uranium and plutonium and also to provide information to assist with pot cleaning. Savannah River National Laboratory (SRNL) was requested by Liquid Waste Organization (LWO) Engineering to obtain these samples from two locations within the evaporator. Past experience has proven the difficulty of successfully obtaining solids samples from the 2H Evaporator pot. To mitigate this risk, a total of four samplers were designed and fabricated to ensure that two samples could be obtained. Samples had previously been obtained from the cone surface directly below the vertical access riser using a custom scraping tool. This tool was fabricated and deployed successfully. A second scraper was designed to obtain sample from the nearby vertical thermowell and a third scraper was designed to obtain sample from the vertical pot wall. The newly developed scrapers both employed a pneumatically actuated elbow. The scrapers were designed to be easily attached/removed from the elbow assembly. These tools were fabricated and deployed successfully. A fourth tool was designed to obtain sample from the opposite side of the pot under the tube bundle. This tool was fabricated and tested, but the additional modifications required to make the tool field-ready could not be complete in time to meet the aggressive deployment schedule. Two samples were obtained near the pot entry location, one from the pot wall and the other from the evaporator feed pipe. Since a third sampler was available and all of the radiological controls were in place, the decision was made to obtain a third sample. The third sampler dropped directly below the riser to obtain a scrape sample from the evaporator cone. Samples were obtained from all of these locations in sufficient quantities to perform the required analysis
Checklist of Bees (Hymenoptera: Apoidea) From Managed Emergent Wetlands in the Lower Mississippi Alluvial Valley of Arkansas
Background
Here we present the results from a two-year bee survey conducted on 18 managed emergent wetlands in the lower Mississippi Alluvial Valley of Arkansas, USA. Sample methods included pan traps, sweep netting and blue-vane traps. We document 83 bee species and morphospecies in 5 families and 31 genera, of which 37 species represent first published state records for Arkansas. The majority of species were opportunistic wetland species; only a small number were wetland-dependent species or species largely restricted to alluvial plains. New information
We present new distributional records for bee species not previously recorded in managed emergent wetlands and report specimens of thirty-seven species for which no published Arkansas records exist, expanding the known ranges of Ceratina cockerelli, Diadasia enavata, Lasioglossum creberrimum, Svastracressonii and Dieunomia triangulifera. We also distinguish opportunistic wetland bee species from wetland-dependent and alluvial plain-restricted species
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