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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.
1

Relative abundance and habitat characteristics of woodland hawks in east-central Indiana

Basey, Gary L. January 1998 (has links)
This study investigates the status and habitat characteristics of the Cooper's Hawk (Accipiter cooperi), the Red-shouldered Hawk (Buteo lineatus), the Broadwinged Hawk (Buteo platvpterus), and the Red-tailed Hawk (Buteo 'amaicensis) in East-central Indiana to provide information useful for the conservation of these species. Surveys of hawks were conducted using taped Great-horned Owl broadcasts at 350 points between April and July, 1995 and 1996. The relative abundance was estimated using the proportion of area occupied technique. Estimates of the proportion of area occupied by each species ranged from 4% to 34%. Red-tailed Hawks were estimated to occupy 34% of the area surveyed. Estimates of the area occupied by Cooper's Hawks was 8% and by Red-shouldered Hawks was 4%. Broad-winged Hawks only occupied two points, therefore no estimate of the area occupied was determined. Macro-habitat characteristics were quantified for each species within a 0.8-km radius of the center of each occupied area and were compared with randomly selected unoccupied areas. Large forested areas with less human development were most preferred by Red-shouldered and Broad-winged Hawks. Cooper's hawks and Red-tailed hawks were found in a wide variety of habitat types. / Department of Biology
2

The expansion of the eastern house finch population and its impact on populations of house sparrows, purple finches and American goldfinches

Hamilton, Thomas Robert January 1991 (has links)
Houses Finches became a breeding species in Indiana in 1981 and subsequently went through a rapid population increase. This study was an investigation of the growth of the House Finch population and its impact on House Sparrows, American Goldfinches and Purple Finches in Indiana. Data from the Annual Christmas Bird Counts of the National Audubon Society (CBC) were used to construct five winter range maps to show the expansion of the House Finch population since 1940. A population density map based on the CBCs of 1988 and 1989 was constructed using birds counted per party hour.CBC data collected during 1965 to 1989 at twelve locations in Indiana were used to track long-term changes in the populations of House Finches, House Sparrows, American Goldfinches and Purple Finches. The number of House Finches counted in Indiana since 1981 increased dramatically. The size of the House Sparrow population appears to have been in a long-term decline for the last 25 years. However, American Goldfinches have, in general, increased in abundance since 1979. The abundance of Purple Finches in Indiana in the winter varies erratically.Observations at backyard feeding stations frequented by House Finches and House Sparrows show that House Finches tend to displace other House Finches more often than would be expected if the displacements occurred in proportion to the frequency at which the birds appear in the population. House Sparrows were found to displace other House Sparrows at a rate which greatly exceeded the expected frequency based on their proportion of the population. Both species tend to avoid interspecific interactions.Field studies in Muncie, Indiana show that House Finches commonly nest in shrubbery and building decorations while House Sparrows often nest in crevices in old buildings and bird houses. No direct competition for nesting sites was observed.Banding studies indicate that during the fall and winter there is a constant turnover of House Finches in Muncie. Using banding data from the U. S. Fish and Wildlife Service it was found that House Finches in the Midwest tend to travel in a southern direction as the season changes from summer to winter and in a northern direction as the season changes from winter to summer. The study shows that House Finches have a strong propensity to return to the same general area each summer. / Department of Biology
3

Cerulean warbler population and breeding response to recent silviculture and influences of prey availability on avian nesting ecology

Wagner, Jennifer R. 05 May 2012 (has links)
This study presents the results of a field study comparing the effects of two forest harvest methods on the Cerulean Warbler, a state-endangered songbird. Population estimates and a breeding study produced no significant differences among groups, although the species was not attracted to forest openings and experienced decreased nest success in treated sites. Additional study on prey influences showed strong correlations with timing of breeding and peak larval lepidopteran abundance, specifically on oak and hickory tree species. Data suggests that these trees are vital to increased probability of nest success due to an increase in prey availability within territories. Further study is recommended to ascertain the long-term effects of forest harvest and the importance of oak and hickory dominated landscapes to the persistence of this species. / Cerulean warbler population response and nesting success in forests with recent silviculture -- Avian nesting ecology and prey abundance using frass drop as an indicator. / Department of Biology

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