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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
81

Some of the Relationships Between Livestock Grazing and Duck Nesting in the Saltgrass Vegetation Type in Utah

Murdy, Horatio W. 01 May 1953 (has links)
Little is known of the relationships between livestock grazlng and duck nesting. This dearth of information occurs in spite of the fact that an understanding of these relationshipships is necessary in order to evaluate duck production on range land, and to formulate grazing policies for lands devoted to the production of ducks. Recognizing the need for information on this subject, the Utah Cooperative Wlldllfe Research Unit and the Wildlife Management Institute jointly sponsored a study, during 1948-1949, of livestock grazing-duck nesting relationships in the saltgrass vegetation type in northern Utah. The study was financed by the Institute and supervised by the research unit. The writer was employed to make the study. This thesis presents his findings. The saltgrass type was chosen for study because it is an extensive vegetetlon type on the wet, alkaline lands of the Great Basin. It occurs at the duck-producing river deltas and marshes on land which is too alkaline for agriculture and is therefore used for grazing. Such lands are low enough in monetary value to permit their purchase for waterfowl management areas.
82

Spawning and Early Life History of Largemouth Bass (Micropterus salmoides) in Wahweap Bay, Lake Powell

Miller, Kent D. 01 May 1971 (has links)
Spawning time and habitat of largemouth bass, survival of embryos, and growth and food habits of fingerlings were studied in 1968 and 1969 at Wahweap Bay, Lake Powell. Spawning began in mid- to late-April, when mean daily water temperature at nesting depths was 14.4-15.0 Centigrade (58-59 Fahreheit), and continued until mid-June. Most spawning took place on the northeast shore of the bay. Sandstone rubble was the most commonly used bottom type for nesting, either at the base of ledges or around large sandstone boulders. Mean nest depth increased from 1.63 meter to 4.54 meters (5.36 feet to 14.90 feet) in 1968 and from 1.51 meter to 2.93 meters (4.96 feet to 9.60 feet) in 1969, because bass sought the protection of ledges and boulders covered by continually rising water. Nearly all embryos required 4 days to hatch, and survival to hatching was 80.4 percent and 92.2 percent for 1968 and 1969, respectively. Growth of fingerlings was similar in both years and most rapid prior to August 1 in both years. Fingerlings from the 1969 year-class were longer than those from the 1968 year-class before August 21. Total length of bass on August 21 was 68.0 millimeters in both years but 86.5 millimeters and 80.2 millimeters on October 1 in 1968 and 1969, respectively. Growth may have been influenced by total temperature experience during the early part of the growing season but not during the latter part. Fingerlings ate mostly crustaceans, insects, and fish. Size of organisms eaten increased with increase in fingerling length, and fingerling bass fed selectively on larger Crustacea. Numbers of nests located and numbers of young-of-the-year taken in beach-seine catches indicated that the 1968 year-class was stronger than 1969. Estimated numbers of bass per 92.9 meters2 (1,000 feet2 ) seined varied from 0.82 to 3.39 in 1968 and from 0.23 to 2.65 in 1969. An index to year-class strength may be obtained from seine catches at any time of the summer after brood dispersal, but indices obtained in this study must be validated by determing the contribution of each year-class to the creel.
83

A Discriminant Function Model of Gray-headed Junco Habitat

Grainger, Andrew W. 01 May 1978 (has links)
This paper presents a description of gray-headed junco habitat in the form of a model based on discriminant function analysis. Junco nests were found by searching randomly located grids on a 7.8 km2 study area in central Utah. Vegetation data was gathered on 500 m2 circular plots surrounding nests and contrasted with similar data from searched grids where nests were not found. The model explains 28 percent of the between-groups variance and correctly classifies 68 percent of the plots. Plant cover types are good predictors of areas where gray-headed juncos nest, while plant community type descriptions do not distinguish between utilized and unutilized areas. The use of quantitative models of wildlife habitat with data derived from various kinds of information systems is discussed.
84

Approche numérique et expérimentale pour une meilleure description physique des processus de subméso-échelle : Application à la mer Méditerranée nord-occidentale / Numerical and experimental approach for a better physical description of submesoscale processes : A north-western Mediterranean Sea case

Declerck, Amandine 09 December 2016 (has links)
L'objectif général de cette thèse est de contribuer à l'avancement de la connaissance de l'impact de l'activité àméso-échelle du Courant Nord (CN) au large du Var sur sa circulation en aval et des interactions de ce courantde bord avec la dynamique côtière, particulièrement dans une baie semi-fermée peu profonde : la baie deHyères. Ces travaux se sont appuyés sur deux configurations numériques réalistes à haute résolution basées surle code NEMO et emboîtées avec AGRIF : une première de la façade méditerranéenne française à unerésolution spatiale de 1,2 km et une seconde le long des côtes varoises à 400 m de résolution.La comparaison des simulations obtenues avec des observations (radar HF, ADCP, glider, SST satellite) apermis de confirmer le réalisme des configurations, et de montrer l'apport d'une résolution de l'ordre de 400 msur la dynamique dans une baie mais également sur le CN et son écoulement en aval.Enfin, une étude de paramétrisation de l'advection horizontale et du mélange vertical a permis d'améliorerl'impact d'un downscaling dans la région d'étude, et particulièrement concernant la représentation de lacirculation au sein de la baie semi-fermée. / The main objective of this work is to improve our knowledge on the impact of the Northern Current (NC)mesoscale activity off the Var coast on its downstream flow and on the links between this boundary current andthe coastal dynamics, particularly in a semi-enclosed bay and shallow: the bay of Hyères. To do so, twonumerical realistic configurations at high-resolution were used. Based on the NEMO code and nested withAGRIF, the first one covers the French Mediterranean coasts at 1,2 km and the second one covers the Varcoasts with a spatial resolution of 400 m.Simulations comparisons with ocean observations (HF radar, ADCP, glider, satellite SST) confirm therealism of the configurations, and show the contribution of a 400 m spatial resolution on the simulateddynamics in the bay but also on the NC and its downstream flow.Finally, a parametrization study on the horizontal advection terms and vertical mixing provide an improvementof the impact of a downscaling in the studied area, and particularly for the simulated dynamics in the semienclosedbay.
85

Population biology of Ross's geese at McConnell River, Nunavut

Caswell, Jason Hughes 25 March 2009
Understanding what influences movement patterns in animals is important to the understanding of colonization, range expansion, and sourcesink dynamics. Rosss geese (Chen rossii) have been expanding their nesting range eastward, and, as recently as 1994, have been nesting in large numbers in such newly colonized areas. I sampled nests at the McConnell River Migratory Bird Sanctuary (MCR), the largest known Rosss goose nesting colony outside the Queen Maud Gulf Migratory Bird Sanctuary (QMG) to estimate its nesting population size. To understand whether immigration by Rosss geese to a new colony located outside traditional nesting areas has an adaptive basis, I compared nutritional, nesting, and survival metrics between geese nesting at the MCR and those nesting at Karrak Lake (KAR) in QMG. I hypothesized that because of longer nesting season, Rosss geese at MCR would have more fat and protein reserves, larger clutch sizes, and greater nest success than those at KAR. Additionally, I hypothesized that population change at MCR was due largely to in situ recruitment. To better understand factors motivating dispersal, movement by Rosss geese between nesting attempts at MCR was measured between years. I hypothesized that dispersal distance of nesting females between years t, and t+1 was a function of both a females own reproductive success as well as that of her neighbours.<p> In 1997 over 23,000 Rosss geese were counted at MCR. By 2007, population estimates (± SE) had increased to 81,408 (±12,367). Survival of both juvenile and adult geese marked at MCR was similar to those nesting at KAR; however, recovery rate estimates were greater than those for KAR. On average, Rosss geese arrived and initiated nests at MCR seven days earlier than at KAR. Abdominal fat was lower when nest initiation date was later in both areas, but was generally greater in geese nesting at MCR. Similarly, there was more indexed protein in geese at MCR than those at KAR in 2 of 3 years. Nesting indices such as clutch size and nest success did not show a consistent area effect, which interacted with a year effect.<p> Rosss geese at MCR did not appear to use individual or conspecific reproductive success when deciding if or how far to disperse between years, and temporary emigration rates also did not vary based on reproductive success the previous year. Instead, variables other than prior individual or neighbour nest success influenced Rosss goose nest site selection and colony fidelity. The number of Rosss geese nesting at MCR increased at an average rate of 11.4% per year from 20032007, despite no increase (0%) from 2006 to 2007. Vital rate information gathered during this time suggests that immigration may have contributed to this growth; however, with few assumptions it can be concluded that MCR is a sustainable population. As a result, studies of geese breeding at MCR provide evidence that arctic geese are capable of successfully colonizing nesting areas great distances beyond historic range.
86

Nesting and duckling ecology of white-winged scoters (<i>melanitta fusca deglandi</i>) at Redberry Lake, Saskatchewan

Traylor, Joshua James 01 December 2003
Population surveys indicate a declining trend in abundance for the scoter genus at the continental level. Little is known about changes in life history traits responsible for the recent population decline of white-winged scoters (<i>Melanitta fusca deglandi</i>, hereafter scoters). Therefore, I studied nesting and duckling ecology of scoters at Redberry Lake, Saskatchewan, Canada during summers 2000-2001 when I found 198 nests. To examine nest-site selection, I compared habitat features between successful nests, failed nests, and random sites. Discriminant function analysis differentiated habitat features, measured at hatch, between successful nests, failed nests, and random sites; lateral (r = 0.65) and overhead (r = 0.35) concealment were microhabitat variables most correlated with canonical discriminant functions. I also modeled daily survival rate (DSR) of nests as a function of year, linear and quadratic trends with nest age, nest initiation date, and seven microhabitat variables. Nest survival from a time constant model (i.e., Mayfield nest success estimate) was 0.35 (95% CL: 0.27, 0.43). Estimates of nest success were lower than those measured at Redberry Lake in the 1970s and 1980s. In addition to nest survival increasing throughout the laying period and stabilizing during incubation, nest survival showed positive relationships with nest concealment and distance to water, and a negative relationship with distance to edge. Considering these factors, a model-averaged estimate of nest survival was 0.24 (95% CL: 0.09, 0.42). I conclude that scoters selected nesting habitat adaptively because (1) successful sites were more concealed than failed sites, (2) nest sites (i.e., successful and failed) had higher concealment than random sites, and (3) nest sites were on islands where success is greater than mainland. I then estimated duckling and brood survival with Cormack-Jolly-Seber models, implemented in Program Mark, from observations of 94 and 664 individually marked adult hens and ducklings, respectively. I tested hypotheses about duckling survival and (1) hatch date, (2) initial brood size at hatch, (3) duckling size and body condition at hatch, (4) offspring sex, (5) maternal female size and body condition at hatch, and (6) weather conditions within one week of hatching. Most mortality occurred during the first six days of duckling age. Variation in both duckling and brood survival were best modeled with effects of hatch date and initial brood size, while effects of female condition, female size, duckling size, and duckling condition were inconsistent. Survival probability clearly decreased with advancing hatch date and increased with larger initial brood sizes. Effects of weather and offspring sex in 2001, the only year such information was collected, suggested survival was negatively related to poor weather, but sex of ducklings, beyond size-related differences (i.e., sexual-size dimorphism), was unimportant. Estimates of survival to 28 days of age (30-day period), whether for ducklings (0.016, 0.021) or broods (0.084, 0.138) in 2000 or 2001, respectively, are the lowest of published studies and first for scoter broods in North America. I suspect intense gull predation shortly after hatch had the largest influence on duckling survival. Further research is needed to ascertain if low nesting success and duckling survival as well as other life cycle components are limiting scoter populations locally and throughout the rest of their breeding range.
87

Nesting and duckling ecology of white-winged scoters (<i>melanitta fusca deglandi</i>) at Redberry Lake, Saskatchewan

Traylor, Joshua James 01 December 2003 (has links)
Population surveys indicate a declining trend in abundance for the scoter genus at the continental level. Little is known about changes in life history traits responsible for the recent population decline of white-winged scoters (<i>Melanitta fusca deglandi</i>, hereafter scoters). Therefore, I studied nesting and duckling ecology of scoters at Redberry Lake, Saskatchewan, Canada during summers 2000-2001 when I found 198 nests. To examine nest-site selection, I compared habitat features between successful nests, failed nests, and random sites. Discriminant function analysis differentiated habitat features, measured at hatch, between successful nests, failed nests, and random sites; lateral (r = 0.65) and overhead (r = 0.35) concealment were microhabitat variables most correlated with canonical discriminant functions. I also modeled daily survival rate (DSR) of nests as a function of year, linear and quadratic trends with nest age, nest initiation date, and seven microhabitat variables. Nest survival from a time constant model (i.e., Mayfield nest success estimate) was 0.35 (95% CL: 0.27, 0.43). Estimates of nest success were lower than those measured at Redberry Lake in the 1970s and 1980s. In addition to nest survival increasing throughout the laying period and stabilizing during incubation, nest survival showed positive relationships with nest concealment and distance to water, and a negative relationship with distance to edge. Considering these factors, a model-averaged estimate of nest survival was 0.24 (95% CL: 0.09, 0.42). I conclude that scoters selected nesting habitat adaptively because (1) successful sites were more concealed than failed sites, (2) nest sites (i.e., successful and failed) had higher concealment than random sites, and (3) nest sites were on islands where success is greater than mainland. I then estimated duckling and brood survival with Cormack-Jolly-Seber models, implemented in Program Mark, from observations of 94 and 664 individually marked adult hens and ducklings, respectively. I tested hypotheses about duckling survival and (1) hatch date, (2) initial brood size at hatch, (3) duckling size and body condition at hatch, (4) offspring sex, (5) maternal female size and body condition at hatch, and (6) weather conditions within one week of hatching. Most mortality occurred during the first six days of duckling age. Variation in both duckling and brood survival were best modeled with effects of hatch date and initial brood size, while effects of female condition, female size, duckling size, and duckling condition were inconsistent. Survival probability clearly decreased with advancing hatch date and increased with larger initial brood sizes. Effects of weather and offspring sex in 2001, the only year such information was collected, suggested survival was negatively related to poor weather, but sex of ducklings, beyond size-related differences (i.e., sexual-size dimorphism), was unimportant. Estimates of survival to 28 days of age (30-day period), whether for ducklings (0.016, 0.021) or broods (0.084, 0.138) in 2000 or 2001, respectively, are the lowest of published studies and first for scoter broods in North America. I suspect intense gull predation shortly after hatch had the largest influence on duckling survival. Further research is needed to ascertain if low nesting success and duckling survival as well as other life cycle components are limiting scoter populations locally and throughout the rest of their breeding range.
88

Revenue Management in the Manufacturing Industry : a model for capacity and pricing strategies in a manufacturing multinational

Löndahl, Ted, Wermstedt, Johan January 2013 (has links)
Revenue management is a concept aimed to maximize capacity utilization and through that maximize revenues. It originated in the airline industry in the 70’s and due to its effectiveness  quickly spread to other sectors of the service industry. Today it is used in several industries like hotels, television and radio broadcasters, and energy transition companies to name a few. Since revenue management was developed in and for the service industry, most studies on revenue management are done on the service industry, creating a rather large research cap. Recently this concept has spread to the manufacturing industry as well. Despite this, there is very limited research done on revenue management in the manufacturing industry. Therefore, this paper’s aim is to partially filling this research gap by studying capacity management and pricing strategies (two mechanisms of revenue management), and how they have been shaped when implemented in a manufacturing company. This paper was done with a case study done on a multinational manufacturing company, who recently implemented revenue management. Interviews were conducted with people in key positions with good insight to the usage of revenue management in this company. Some of the most important result was that in this manufacturing company it is not possible to nest capacity on a customer segment level. However, in this company nesting was done on a market level instead. Also the pricing strategy differed between the service industry theory and this company. Instead of having a dynamic price that changed the total price up or down to change demand, this company had more of a fixed total price, and instead added more features to the product, decreasing the profit margin. The conclusion was drawn that the industry characteristics of the manufacturing industry have forced a rather large modification of revenue management. However, since this was a qualitative case study, no generalizing conclusions for the entire manufacturing industry can be drawn.
89

Population biology of Ross's geese at McConnell River, Nunavut

Caswell, Jason Hughes 25 March 2009 (has links)
Understanding what influences movement patterns in animals is important to the understanding of colonization, range expansion, and sourcesink dynamics. Rosss geese (Chen rossii) have been expanding their nesting range eastward, and, as recently as 1994, have been nesting in large numbers in such newly colonized areas. I sampled nests at the McConnell River Migratory Bird Sanctuary (MCR), the largest known Rosss goose nesting colony outside the Queen Maud Gulf Migratory Bird Sanctuary (QMG) to estimate its nesting population size. To understand whether immigration by Rosss geese to a new colony located outside traditional nesting areas has an adaptive basis, I compared nutritional, nesting, and survival metrics between geese nesting at the MCR and those nesting at Karrak Lake (KAR) in QMG. I hypothesized that because of longer nesting season, Rosss geese at MCR would have more fat and protein reserves, larger clutch sizes, and greater nest success than those at KAR. Additionally, I hypothesized that population change at MCR was due largely to in situ recruitment. To better understand factors motivating dispersal, movement by Rosss geese between nesting attempts at MCR was measured between years. I hypothesized that dispersal distance of nesting females between years t, and t+1 was a function of both a females own reproductive success as well as that of her neighbours.<p> In 1997 over 23,000 Rosss geese were counted at MCR. By 2007, population estimates (± SE) had increased to 81,408 (±12,367). Survival of both juvenile and adult geese marked at MCR was similar to those nesting at KAR; however, recovery rate estimates were greater than those for KAR. On average, Rosss geese arrived and initiated nests at MCR seven days earlier than at KAR. Abdominal fat was lower when nest initiation date was later in both areas, but was generally greater in geese nesting at MCR. Similarly, there was more indexed protein in geese at MCR than those at KAR in 2 of 3 years. Nesting indices such as clutch size and nest success did not show a consistent area effect, which interacted with a year effect.<p> Rosss geese at MCR did not appear to use individual or conspecific reproductive success when deciding if or how far to disperse between years, and temporary emigration rates also did not vary based on reproductive success the previous year. Instead, variables other than prior individual or neighbour nest success influenced Rosss goose nest site selection and colony fidelity. The number of Rosss geese nesting at MCR increased at an average rate of 11.4% per year from 20032007, despite no increase (0%) from 2006 to 2007. Vital rate information gathered during this time suggests that immigration may have contributed to this growth; however, with few assumptions it can be concluded that MCR is a sustainable population. As a result, studies of geese breeding at MCR provide evidence that arctic geese are capable of successfully colonizing nesting areas great distances beyond historic range.
90

Estimating species interactions in a woodpecker tree-hole community at the individual, population, and community levels

Walters, Eric L. James, Frances C. January 2004 (has links)
Thesis (Ph. D.)--Florida State University, 2004. / Advisor: Dr. Frances C. James, Florida State University, College of Arts and Science, Dept. of Biological Science. Title and description from dissertation home page (viewed June 16, 2004). Includes bibliographical references.

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