abstract: Once considered an abundant species in the eastern United States, local populations of red-shouldered hawks, Buteo lineatus, have declined due to habitat destruction. This destruction has created suitable habitat for red-tailed hawks, Buteo jamaicensis, and therefore increased competition between these two raptor species. Since suitable habitat is the main limiting factor for raptors, a computer model was created to simulate the effect of habitat loss in central Maryland and the impact of increased competition between the more aggressive red-tailed hawk. These simulations showed urban growth contributed to over a 30% increase in red-tailed hawk habitat as red-shouldered hawk habitat decreased 62.5-70.1% without competition and 71.8-76.3% with competition. However there was no significant difference seen between the rate of available habitat decline for current and predicted development growth. / Dissertation/Thesis / M.S. Applied Biological Sciences 2011

Master of Science / Department of Civil Engineering / Eugene R. Russell / Pedestrian signals, particularly at signalized, mid-block crossing can cause delay to drivers after pedestrians’ have successfully crossed, which is termed “unnecessary delay” in this study. In many cases at a mid-block signal, a pedestrian pushes the button and then quickly crosses the street as soon as the walk signal appears and drivers still face several seconds of solid red ball and by law must remain stopped. On a busy street, a queue of vehicles waiting after all pedestrians have crossed can amount to hundreds of hours of unnecessary delay per year. The ‘Pedestrian Hybrid Beacon’ (Initially named a HAWK (High Intensity Activated Crosswalk)) Beacon was proven to be effective in decreasing this unnecessary delay when compared to standard signalized mid-blocks. The City of Lawrence, Kansas was interested in experimenting (as a HAWK beacon was considered experimental when they were installed) with a pedestrian hybrid beacon and they installed their first pedestrian hybrid beacon at a mid-block crossing on 11th street and a second pedestrian hybrid beacon at mid-block crossing on New Hampshire street, Lawrence, Kansas, which were the sites of interest for this research. A study was conducted at these sites to determine the effectiveness of the pedestrian hybrid beacon in decreasing the unnecessary delay to drivers by comparing it to a signalized mid-block crossing on Massachusetts Ave in Lawrence, Kansas. Apart from the delay measurements for these two sites, other parameters such as driver compliance rate to the signal, pedestrian compliance rate, and other driver and pedestrian characteristics were also studied. Video cameras were used to capture video at these sites and the effectiveness of the pedestrian hybrid beacon was analyzed from the video. The HAWK, now in the MUTCD as a Pedestrian Hybrid Beacon, proved to be effective in decreasing the unnecessary delay for drivers in this study. The City of Lawrence had a total of six pedestrian hybrid beacons in operation as per the information received in March 2010.

The San Bernardino Mountains are well known for their rich mining history, especially, gold in the mid-1800s and the current mining of one of the world’s largest deposits of high purity limestone. The purpose of this study was to compile new, current, and historical data of the major economic resources that are present and mining that has gone on in the San Bernardino Mountains. It is estimated that historical mining of the Holcomb Valley recovered $457,660,000 of gold or about 350,000 troy ounces based on samples collected for this study and 2013 gold price. The current major geologic resource is the limestone deposits on the north slope of the San Bernardino Mountains. Presently, there are three operators: Omya, Specialty Minerals, and Mitsubishi Cement. The San Bernardino Mountains are well known for skarn gold deposits. New work indicates that the placer gold from Holcomb Valley is often of very high purity. Placer gold samples were analyzed using the scanning electron microscope and energy dispersive x-ray spectra to determine the purity of the gold. Rim and core analysis of the placer gold was used to determine if the gold was transported from its source and to give an estimate of transportation distance. Results show some of the placer gold of Holcomb Valley has been rounded and flattened by weathering and transportation with increased gold purity in the rims while other gold grains still sustain their octahedral crystalline structure. Rims range in gold purity from 84.26% to 100%, with core gold purity ranging from 79.51% to 99.79%. Gold samples were weighed, photographed, measured, and classified by shape, angularity and texture, to assess the effects of transportation. Gold weights where used to calculate an economic value of gold. Geographic Information System “GIS” was used to visually display geology, historical and current mine locations, locations of samples used in this study, and to help calculate the volume of the Holcomb Valley TsE rock unit, which is where the placer gold is deposited. Sediment sample 15 from TsE had the lowest gold value of .002 ounces per cubic yard. This value is inferred to represent the amount of gold remaining after mining. Based on this assumption and the estimated volume of TsE at 50,027,000 cubic yards, the estimated total weight of gold remaining in the deposit is about 100,000 troy ounces, with a dollar value of about $130,760,000, using gold values for 2013. Sample 17 had the highest gold value, with .014 ounces per cubic yard. This is inferred to represent the concentration of placer gold deposits within parts of Holcomb Valley that have never been mined. This yields a total weight of the deposit of roughly 700,000 troy ounces, with an estimated value of $915,320,000 using gold prices for 2013. The gold values were calculated using November 7, 2013 gold spot price of $1,307.60.

The purpose of this study was to examine the hunting strategies of birds of prey in a probability learning situation. One great horned owl and one red-tailed hawk served as subjects. Three boxes and associated perches, each representing different potential prey areas, were placed in a room adjacent to the birds' regular housing and served as test apparatus. One box were required to land on a perch in order to gain access to the associated box and to the potential prey. A discrete-trial, self-correction procedure was used. In Experiment I, Box 1 was loaded with a live laboratory mouse on 60% of the trials, Box 2 on 30% of the trials, and Box 3 on the remaining 10%. A response requirement of sitting on the perch 5 seconds was programmed. In experiment II, the probability of reinforcement was reversed for the 10 and 60% boxes and the response requirement was increased from 5 to 20 seconds. Experiment III returned the probability of reinforcement for each box to the values used in Experiment I. In Experiment III the mice were euthanized prior to each trial. The owl matched responses to probability of reinforcement in all three experiments while the hawk matched in Experiment II and showed matching toward two of the three boxes in Experiment III. In Experiment I the hawk had a Box 2 preference. This research extends the generality of the matching concept and suggests that predatory birds do not randomly hunt or hunt in only one location, but rather tend to search according to the probability of reinforcement for that location.

No description available.

Thesis (Ph. D.)--University of Chicago, Dept. of Anthropology, August 2002. / Includes bibliographical references. Also available on the Internet.

Thesis (M.P.A.)--Kutztown University of Pennsylvania, 2003. / Source: Masters Abstracts International, Volume: 45-06, page: 2935. Typescript. Abstract precedes thesis as preliminary leaves ii-iii. Includes bibliographical references (leaves 98-101).

Several species of raptors are found in prairie landscapes managed and enhanced for waterfowl. Red-tailed Hawks (Buteo jamaicensis ) and Great Horned Owls (Bubo virginianus) may benefit from such management in a manner that is counter to its goals and objectives; that is, waterfowl may comprise a significant proportion of their diet, resulting in a decline in waterfowl numbers. The overall aims of this three-year study were to determine whether the feeding habits of the two raptor species are selective and to determine if waterfowl is a preferred prey group. The diet was determined through pellet analysis, prey remains and direct nest observations during the nestling growth period. Availability of most prey species was assessed through small mammal trapping and by conducting waterfowl censuses. It was determined that both raptors select for duck species. The average waterfowl biomass consumed per nestling represented 21.5% of the total biomass consumed for Great Horned Owls and 23.5% for Red-tailed Hawks. (Abstract shortened by UMI.)

No description available.

Thesis (M.S.M.E.)--Baylor University, 2008. / Includes bibliographical references (p. 101-102).