Physical Sciences and Mathematics Commons^™

Non-Euclidean Geometry, Skyler W. Ross

Electronic Theses and Dissertations

In this country, the typical high school graduate has had at least some exposure to Euclidean geometry, but most lay-people are not aware that any other geometries exist. In this paper we provide an overview of the basics of hyperbolic geometry, one of many Non-Euclidean geometries, that should be accessible to anyone whose mathematical background includes geometry, trigonometry, and the calculus. We will begin with a brief history of geometry and the two hundred years of uncertainty about the independence of Euclid's fifth postulate, the resolution of which led to the development of several Non-Euclidean geometries. After an axiomatic development …

Concurrency Issues In Programmable Brick Languages, Gilliad E. Munden

Electronic Theses and Dissertations

Abstract

The programmable brick constitutes a domain for simple, autonomous robotics geared towards novice programmers in a constructionist setting. A large number of languages have been adapted from other domains to serve as a programming platform for this brick. However, there has yet to be an in-depth analysis of how these languages fit this domain. This work provides such an analysis of the existing brick languages in order to identify how they deal with the issue of concurrency as it relates to the brick. First, the brick domain is characterized and the languages involved are described. Second, the different approaches …

Food Habits And Diet Overlap Of Age-1 And Older Walleye And White Bass In Lake Poinsett, South Dakota, Andrew B. Starostka

Electronic Theses and Dissertations

White bass Marone chysops and walleye Stizostedion vitreum coexist in several of the large glacial lakes in eastern South Dakota. I collected age-1 and older white bass and walleye in Lake Poinsett, South Dakota during May, July and September, 1998 to determine food habits and diet overlap using percent by weight to describe diets and Schoener's index (Cxy) to determine diet overlap. Macroinvertebrates were common prey items for white bass in all length groups during all sample dates. The primary macroinvertebrates consumed by white bass were corixids, amphipods and dipterans. Fish, as a group, were second in diet importance over …

An Implementation Of The El Gamal Elliptic Curve Cryptosystem Over A Finite Field Of Characteristic P, Samuel Thomas Arslanian

Electronic Theses and Dissertations

Since the earliest times, individuals and groups of individuals have been interested in communicating sensitive information in a manner which would guarantee that such information could not be arbitrarily received. Further, such information was to be received by select recipients and this required that a means of secure information transmission be found and employed. To these ends, methods of information encryption have ever since been sought and employed. The entire study and practice of this activity, cryptology, the science of message encryption and decryption, provides a framework for this thesis. In particular, the development of cryptology has been influenced by …

The Wind Cave National Park Elk Herd: Home Ranges, Seasonal Movements, And Alternative Control Methods, Peter Bauman

Electronic Theses and Dissertations

Elk (Cervus elaphus ne/soni) herd organization, movements, and home range size in Wind Cave National Park (WICA) were studied from May 1996 to August 1997. Twenty radiocollared elk ( 10 males, 10 females) were relocated by ground and aerial telemetry. Radiocollared elk were relocated two times/week, resulting in 1,595 relocations ( 410 ground, 1, 185 aerial). Coefficients of association (CA) for radiocollared cows averaged 0.005 during spring/summer 1996, 0.033 during spring/summer 1997, and 0.295 during falVwinter 1996. Coefficients of association for radiocollared bulls averaged 0.011 during spring/summer 1996, 0.015 during spring/summer 1997, and 0.075 during faIVwinter 1996. Three cow subherds …

Owls Of The Idaho National Engineering And Environmental Laboratory (Ineel), Natalie A. Fahler

Electronic Theses and Dissertations

The Idaho National Engineering and Environmental Laboratory (INEEL) is a 2,315 km2 energy research and development site located on the Upper Snake River Plain of Southeast Idaho. Owl research was conducted on the site during the spring and summers of 1996-1997. Objectives were to: a) determine productivity, habitat use, and possible nest site selection factors of burrowing owls (Athene cunicularia ), b) verify the presence of small owl species including the boreal owl (Aegolius funereus), the northern saw-whet owl (A. acadicus), the western screech owl (Otus kennicottii), the flammulated owl (0. flammeolus), and the northern pygmy owl (Glaucidium gnoma), c) …

Passerine Use Of Grasslands Managed With Two Grazing Regimes On The Missouri Coteau In North Dakota, Natoma A. Schneider

Electronic Theses and Dissertations

Several rotational grazing systems have been implemented on the Missouri Coteau in central and northcentral North Dakota as part of the Prairie Pothole Joint Venture (PP N). The impacts these systems have on grassland passerines are not fully understood. Objectives for this study include determining relative abundance, species composition and reproductive success of passerines as well as vegetation characteristics for rotational and traditional season-long grazing regimes. Passerine relative abundance and species richness were determined on rotational grazing systems during 1995-1997 and on season-long grazed pastures during 1996-1997 using 122 fixed, 100 m radius, point counts. Relative abundance was assessed by …

Calibration Methodology And Multiple Tip Structure By Scanning Tunneling Microscopy., Michael Stephen Gossman

Electronic Theses and Dissertations

The scanning tunneling microscope has been in commercial use just over a decade. Due to its Quantum Mechanical nature, experiments in this area have been widely publicized to the scientific community. The apparatus is steadily growing easier to use, though fundamental problems are still present. In the first chapter, an address is given on the modem theory of tunneling to rationalize the conclusions Physicists made long ago about this phenomenon. The expanded theory generalizes the mathematical motivation for attempting such unique experiments and serves as a lead-in for the major components of the apparatus. Many texts do not quantize what …

Habitat Area Requirements Of Prairie Wetland Birds In Eastern South Dakota, David E. Naugle

Electronic Theses and Dissertations

The influence of area and vegetation structure on bird use of 830 semipermanent and seasonal wetlands (0.2-217.5 ha) was studied to evaluate vegetative needs and habitat area requirements of 20 breeding wetland bird species in eastern South Dakota in 1995-1996. Vegetative preferences of species varied, but most waterfowl and nongame species occur e4i more frequently in wetlands with intermediate cover-to-water ratios whereas five over-water nesting or secretive nongame species were found in wetlands with greater coverage of emergent vegetation. The occurrence of four nongame species that depend on vegetative structure to support the weight of their over-water nests also was …

Early Life History Of Yellow Perch In Eastern South Dakota Lakes, Shannon Fisher

Electronic Theses and Dissertations

Yellow perch Perea flavescens are a popular South Dakota sportfish; however, inconsistent recruitment creates highly variable and unpredictable perch fishery quality. Before fishery managers can begin to develop and assess strategies to stabilize yellow perch recruitment, a better understanding of their early life history is required. I selected two natural lakes with differing yellow perch population types and monitored brood stock, spawning habits, and larval and juvenile life history patterns during 1995 and 1996. Pelican Lake was selected as a representative yellow perch population exhibiting inconsistent recruitment and Pickerel Lake as a population with relatively consistent recruitment. Yellow perch tended …

Preprocessing Of Microcirculatory Images., Mohamed S. Mansour

Electronic Theses and Dissertations

This thesis project consists of the development of a computerized image processing system to preprocess microvascular images of the mouse Latisimus Dorsi Muscle (LDM). This research has been conducted in association with the Division of Plastic and Reconstructive Surgery at the University of Louisville. The input to the system is a set of 35 or more overlapping microscopic fields or sub_images containing segments of the LDM microcirculation, the output is an adjacent single montage encompassing the entire LDM microvasculature. The developed system presents practical solutions to the problems of image registration, overlap resolution, and image segmentation, in addition, the results …

Bioenergetics Of Walleye In Lake Oahe, South Dakota, Scott D. Bryan

Electronic Theses and Dissertations

The food habits, caloric density, and population dynamics of walleye Stizostedion vitreum were determined in 1993 and 1994 and combined with information on energetics and growth to determine the trophic interactions of walleyes in Lake Oahe, South Dakota. Monofilament gill nets were set at three depths in the water column (bottom, suspended, and surface) from May through September, 1994 to determine the effect of gill net placement on catch rates of walleyes. Catch per unit effort of walleyes was greater in bottom nets during July (5.2/net-h) than any other month or net location. In addition, 25- and 38-mm mesh sizes …

Beaver Recolonization In South-Central Maine, Laurence Lisle Ii

Electronic Theses and Dissertations

Following a long absence due to over-trapping, beaver (Castor canadensis) recolonized most of their continental range during the middle of the 20th century. The spread of beaver across the landscape was revealed by the emergence of beaver-created wetlands, or flowages. Based on the appearance of flowages on aerial photographs from 1939, 1957, 1974, and 1991, I documented the return of beaver to a 105 km^ watershed in south-central Maine. I sought to determine if certain wetland characteristics—area, perimeter to dam length (p/d) ratio, and watershed size—influenced the order in which sites were occupied by beaver. Also, to gauge the effect …

Raptor Use Of The Idaho National Engineering Laboratory, Richard Wayne Hansen

Electronic Theses and Dissertations

Raptors are high trophic-level predators, and thus sensitive to environmental change. I conducted a basic ecological study of raptors using the Idaho National Environmental Laboratory (INEL), in southeastern Idaho, between 1991 and 1993 to assess effects of human activity on the site. Results were compared to previous raptor studies conducted on the INEL from 1974-1976 and in 1982, as well as with studies of rough-legged hawks, long-eared owls, and burrowing owls conducted during the late 1970’s and early 1980’s. Road-side raptor surveys were conducted from January through May in 1992 and 1993. Principle species recorded were rough-legged hawks, red-tailed hawks, …

Winter/Spring Population Characteristics Of White-Tailed Deer In An Agricultural/Wetland Complex In Northeastern South Dakota, Brian J. Kernohan

Electronic Theses and Dissertations

Habitat preference, cover characteristics of corn, movements, and sexual segregation patterns of white-tailed deer (Odocoileus virginianus) were evaluated at Sand Lake National Wildlife Refuge (SLNWR) in winter (January - March) and spring (April - June), 1993 and 1994. An average of 20 radio-collared deer were monitored per season, which resulted in 4, 058 relocations. Habitat preference was assessed using 95 and 50% home range contours that were estimated using an adaptive kernel method. Agricultural crops (i.e., corn [Zea mays], row crops other than corn [e.g., soybeans [Glycine max]], small grains [e. g., wheat [Triticum aestivum]], and alfalfa [Medicago sativa]) were …

Winter Diet And Nutritional Condition Of White-Tailed Deer In The Northern Black Hills, South Dakota, Robert G. Osborn

Electronic Theses and Dissertations

Habitat deterioration in the northern Black Hills (NBH) of South Dakota may be responsible for declining white-tailed deer (Odocoileus virginianus) population levels (Griffin et al. 1992). Because of the relationship between habitat and nutrition, a two-year research project was initiated in January 1992 to evaluate the physical and nutritional condition of white-tailed deer inhabiting five NBH winter subranges. Habitat variables were measured at 100 random locations on each study area. Pellet groups were collected throughout each study area at two-week intervals during January, February, and March 1992 and 1993. Five female white-tailed deer were collected from each study area in …

A Characterization Of Extractable, Hydroxylated Fatty Acid Bearing Components In Legionella Pneumophila, Jonathan R. Lane

Electronic Theses and Dissertations

Extraction of the lipids of Legionella pneumophila yields phases unlike those produced from other Gram-negative bacteria. A viscous interface forms between the aqueous (wash) and organic phases. More than half of the hydroxylated fatty acids were found distributed between the aqueous phase and the interfacial material, fractions in which such constituents have not been reported in other Gram-negative species. It was further observed that after the material from the aqueous/interfacial phase was dissolved in methanol or chloroform/methanol (2:1 (V/V)), the addition of acetone would create a white, flocculent precipitate. Analyses showed that the supernatant contained fatty acids that were nonhydroxylated …

The Development Of A Solar Radiation Extinction Correction For Satellite Data, Widad I. Mohamed

Electronic Theses and Dissertations

The main objectives of this thesis are the following: 1) Remove the haze using water surfaces in Landsat satellite imagery of the visible and near-infrared regions for their properties of high absorption of solar radiation and weak reflection of it. The scattered solar radiation is most obvious in dark weakly reflecting regions such as water. The haze removal technique depends on subtraction of scattered light from picture elements within the satellite imagery. 2) Derive a formula and techniques for a given image to correct for extinction by transforming the observed intensity of the signal transmitted to the Landsat detector to …

Population Status And Characteristics Of Macrhybopsis Gelida, Platygobio Gracilis And Rhinichthys Cataractae In The Missouri River Basin, Selena J. Werdon

Electronic Theses and Dissertations

Few sturgeon chub (Macrhybopsis gelida: Cyprinidae) have been collected in the last decade, therefore their status, habitat selection and morphology were investigated at 172 previous collection sites. Data on two ecologically similar species, Platygobio gracilis and Rhinichthys cataractae, were also collected. Macrhvbopsis gelida were collected at 28 sites on the Powder River (n = 158) in Wyoming and Montana, and at one site on the Yellowstone River (n = 1) in Montana. Age-I, Age-II and Age-III M. gelida were collected. Specimens were 37 to 95 mm in total length. Macrhvbopsis gelida were ripe in mid-June, at water temperatures of 18.3-22. …

Factors Limiting Overwinter Survival Of Young-Of-The-Year Largemouth Bass In South Dakota, Todd D. Kolander

Electronic Theses and Dissertations

Studies were conducted to examine the effects of total length (TL), prey abundance, and water temperature on approximate body composition, condition index, and overwinter survival of young-of-the-year (YOY) largemouth bass Micropterus salmoides in South Dakota. Growth and condition of YOY largemouth bass stocks from South Dakota and Wisconsin were also compared. Study areas included two South Dakota University impoundments (0.8 hectare each), a gravel pit (7. 3 hectare), and laboratory aquaria. Hatchery reared YOY largemouth bass were graded into short (19-45 mm TL) and long (58-135 mm TL) length groups. Overwinter mortality was 78% and 85% in the two impoundments, …

Preliminary Epidemiological Interpretation Of The Intrinsic And Extrinsic Factors Contributing To The Coverage And Participation Rates Of The Vaccination Program In Arssi, Ethiopia, Muchie Kidanu

Electronic Theses and Dissertations

Many immunization programs in developing countries arr now undergoing a period of rapid utilization. Innovative strategies, such as immunization holidays, are being tried. Political commitment and enthusiasm are high. There is a strong desire by health professionals to protect the lives of many children from the untimely death and/or disability resulting from infectious diseases preventable by vaccination.

Evaluation of an immunization program can benefit other elements of the health system, particularly those that are not amenable to objective evaluation as immunization. In this case, immunization can serve as an indicator of the overall performance of the health system. The problems …

Forage Potential Of Seasonal Wetlands, Daniel Edward Hubbard

Electronic Theses and Dissertations

Investigations on aspects of seasonal wetland forage potential were conducted in eastern South Dakota. The quantity and quality of the standing crop of vegetation in 6 seasonal wetland communities were assessed at the end of the growing season in 1983 and in 2 seasonal-wetland-dominated basins and their associated uplands (native mixed-grass prairie) over the growing season in 1985. Crude protein (CP), ash, detergent fiber, and in vitro digestible dry matter (IVDDM) values were measured on the above-ground material of whitetop [Scolochloas festucacea (Willd.) Link], slough sedge (Carex atherodes Spreng.), burred (Spargnaium eurycarpum Engelm.), and smartweed (Polygonum amphibium L. var. emersum …

Conservation Of Least Terns And Piping Plovers Along The Missouri River And Its Major Western Tributaries In South Dakota, Monica Jean Schwalbach

Electronic Theses and Dissertations

Interior least terns (Sterna antillarum) and piping plovers (Charadrius melodus) are listed as endangered or threatened over all of their breeding range, including South Dakota (SD). Investigations were made into the status, distribution, production, habitat characteristics, and factors limiting productivity of least terns and piping plovers in SD. The study area included the Missouri River from the North Dakota state line to Ponca State Park, Nebraska, and the lower 1/3 of the Grand, Moreau, Cheyenne, and White rivers. Least tern numbers increased substantially (253; 367) between 1986 and 1987, but plover numbers increased only slightly (187; 197). Terns and plovers …

Productivity, Movements, And Habitat Use Of Nesting And Brooding Wild Turkey Hens In Gregory County, South Dakota, Keith Stephen Day

Electronic Theses and Dissertations

Radio-equipped wild turkey (Meleagris gallopavo) hens (n=53) were monitored in a prairie river breaks environment in south-central South Dakota during 1986 and 1987. Seventy percent (36 of 47 adults and 1 of 6 juveniles) of the monitored hens nested. Hens that nested prior to 7 May selected nest sites in woodland habitats, while hens nesting later than 7 May selected nest sites in grassland habitats. Hens nested at sites with higher (P<0.05) percent visual obstruction, percent shrub cover, presence of overhanging vegetation, and habitat diversity than found at random control sites. Nest sites also allowed greater field of vision and opportunities for escape than random controls. Discriminant models developed from variables measured at nest and control sites were effective in distinguishing between the 2 categories. Seventeen of 39 (43.6%) clutches hatched, and 11 broods survived to mid-August. Poult survival in 1986 was 42.9%, with all poult mortality occurring during the first 2 weeks post-hatch. Accurate data for poult survival was not obtainable during 1987, but survival appeared to be similar to 1986. Broods moved up to 3.5 km from nest sites before establishing definite ranges. Broods ranges were composed of ≥50% woodland types, while woodlands comprised only 30.8% of the study area. Mean range size increased 3-fold from the 0-4 week age class (Age 1) to the 4+ week age class (Age 2). Broods used habitats in proportion to availability within ranges. However, grasslands were used more than expected (P<0.05) between 0631 hr and 1130 hr over the summer, and less than expected (P<0.05) by Age 2 broods between 1131 hr and 1630 hr. Woodlands were used more than expected between 1131 hr and 1630 hr over the summer, but not significantly so. Seventy-seven percent of all brood sightings made between 0631 hr and 1130 hr, and 67% of all sightings made between 1631 hr and 2030 hr were in grassland habitats. Seventy-two percent of all brood sightings made between 1131 hr and 1630 hr were in woodlands. Grassland brood use sites had greater forb cover, less grass cover, and were closer to habitat edges than random control sites (P<0.05). Discriminant analysis effectively reclassified grassland brood use sites, but not control sites. Age 1 broods sued grassland sites with greater overhead (> 30 cm) shrub cover, and nearer habitat edges than sites used by Age 2 broods (P<0.05). Woodland brood use sites were nearer (P<0.05) habitat edges than random controls. No significant differences could be found between woodland sites used by Age 1 and Age 2 broods. Discriminant analysis was ineffective in distinguishing between classes for woodland brood use sites or between ages for either woodland or grassland brood use sites.

Wetland Characteristics Of Avian Cholera Outbreaks And Surface Water Transfer In The Nebraska Rainwater Basin Area, Brian J. Smith

Electronic Theses and Dissertations

Avian Cholera (Pateurella multocida) has infected and killed thousands of migrating waterfowl each year since 1975 in Nebraska’s rainwater basin area. Disease outbreaks in migrating waterfowl populations just prior to the nesting season are of concern to biologists. Feedlots and itner-wetland basin surface water transfer mechanisms of the avian cholera causative agent, P. multocida, were investigated using remote sensing techniques. Wetland basin characteristics (classification type, adjacent landuse, basin landuse, and basin densities) were also investigated for relationships to 1981 avian cholera outbreaks. No surface drainage relationships were found that would permit the transfer of P. multocida from one wetland basin …

The Effect Of Grass Carp Introduction On Aquatic Vegetation And Existing Fish Populations In Two Small Prairie Lakes, David L. Bauer

Electronic Theses and Dissertations

Within two years after triploid grass carp introduction in 2.3 hectare Prior Lake in South Dakota, aquatic vegetation coverage and height in the water column were significantly lower (P<0.005). During the same two year period, triploid grass carp did not significantly reduce aquatic vegetation coverage or height in the water column in 11.4 hectare East Lake Eureka, also in South Dakota. Stocking densities were 49 fish/hectare and 61 fish/hectare (229 mm mean total length) in Prior Lake and East Lake Eureka, respectively. The biomass of prey fish in East Lake Eureka in 1986 was quite high with 88.3, 85.3 and 17.3 kg/hectare for black bullhead (Ictalurus melas), yellow perch (Perea flavescens), and bluegill (Lepomis macrochirus), respectively. The biomass of northern pike (Esox lucius) was also high at 13.8 kg/hectare. A Proportional Stock Density (PSD) of 11 and Relative Weight (WK) of 117 indicated a relatively healthy bluegill population in East Lake Eureka. However, the PSD value for black bullheads was lower (8) while their condition was relatively good (K=l.58). The yellow perch population appeared to be over-populated in East Lake Eureka with a PSD of only 5 and a relatively low condition factor (K=l.14). The northern pike population in East Lake Eureka had a PSD value of 53, but a slightly low Wr of 94. Available prey/predator ratio indicated that there was an excess of prey fish for most size classes of predators. Because no significant vegetation reduction occurred in East Lake Eureka, no changes in existing fish populations could be attributed to grass carp introduction or aquatic vegetation reduction. Data gathered on existing fish populations in East Lake Eureka will serve as a pre-treatment data set to be compared to future conditions if aquatic vegetation is reduced. Fish sampling in Prior Lake was greatly reduced due to a winterkill which occurred in the late winter of 1986. Bluegill and largemouth bass (Micropterus salmoides) were the most abundant fish species found in Prior Lake in 1987. Bluegill appeared to be overpopulated as their PSD value was 1; a high Wr of 109 may have indicated improved conditions immediately following the winterkill. Results for the largemouth bass in Prior Lake were similar with a low PSD (7) and a high w~ (112). Winterkill (Prior Lake) and lack of aquatic vegetation control by grass carp (East Lake Eureka) prohibited making conclusions about the effect of grass carp introduction on the existing fish populations in the two lakes. Further research needs to be conducted in South Dakota to determine appropriate grass carp stocking rates for South Dakota waters, and to evaluate what effect grass carp introduction and aquatic vegetation reduction has on existing fish populations.

Production Of Triploid Rainbow Trout For Evaluation In South Dakota Waters, Jeff C. Dillon

Electronic Theses and Dissertations

In September 1986, approximately 50,000 rainbow trout (Salmo gairdneri) eggs were fertilized and subjected to heat shocks to prevent expulsion of the second polar body, theoretically resulting in triploid embryos. Heat shocks were at 26 and 28°c, began 10, 20, 30, or 40 min after fertilization, and lasted for 10 or 20 min for a total of 16 treatments. Another 25,000 eggs served as controls and were handled identically but at a normal water temperature of 12°c. Cumulative hatching rates for eggs that were heat-shocked at 26 and 28° were 64 and 50%, respectively, compared to control eggs which had …

Electrophoretic, Morphometric, And Meristic Comparisons Of Walleye Broodstock In South Dakota, Chantel M. Waltner

Electronic Theses and Dissertations

Electrophoretic and morphological variability among walleyes collected from three upper Missouri River tributaries and a glacial lake in South Dakota was investigated, and an upper Mississippi River stock was electrophoretically compared to the South Dakota stocks. Allele frequencies of two (MDH-3, GMP-3) of the twenty-one loci examined differed significantly (P<0. 05) between South Dakota and Mississippi River walleyes. Contingency chi-square tests of allele frequencies showed homogeneity among walleyes from the Missouri River tributaries, and significant (P<0.001) heterogeneity (P<0.001) at the GMP-3 locus between Missouri River and glacial lake stocks. A dendogram derived from Nei unbiased genetic identity values produced separate branchings for the South Dakota and Mississippi River walleyes. All four walleye stocks in South Dakota were morphologically variable, although no one character could be used as a diagnostic tool to separate the stocks visually. Discriminant function analysis of eight of the most powerful discriminatory characters was successful in correctly classifying walleyes by origin with 83-97% accuracy.

Growth, Survival, And Vulnerability To Predation Of Stocked Walleye (Stizostedion Vitreum) Fingerlings, James D. Wolters

Electronic Theses and Dissertations

In laboratory tanks, largemouth bass (Micropterus salmoides) and northern pike (Esox Lucius consumed fathead minnows (Pimephales promelas) 2.6 times more frequently than walleye (Stizostedion vitreum) and 5.7 times more than lepomids. Prey were more vulnerable in circular than rectangular tanks. In field studies, walleye fingerlings averaging 35 mm and 53 mm (mean total length) were stocked in two ponds (3- and 7- hectares) respectively: both contained largemouth bass, northern pike, yellow perch (Perca flavescenes), green sunfish (Lepomis cyanellus), and fathead minnows. Aquatic insects dominated the diet of largemouth bass for 3 days after walleye were stocked, indicating that walleye fingerlings …

Waterfowl Production On Three Types Of Artificial Nesting Structures In South Dakota Wetlands, Marcy Haworth

Electronic Theses and Dissertations

Artificial nesting structures are currently being used by various agencies to offset the decline in waterfowl production due to predation losses and degradation of nesting habitats. However, the various structure types available are not equally attractive to nesting waterfowl. This study looked at 3 types of artificial nesting structures – open topped cone baskets, round hay bales, and concrete culverts – and evaluated their used, success, and production in South Dakota. Structure type and site characteristics were correlated to occupancy rates and nesting success. Sixty-eight baskets and 205 bales were monitored during 1986, and 154 baskets, 200 bales, and 20 …