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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

Tree species preferences for foraging site and ways in which the preferences affect the distribution, abundance and species composition of arboreal woodland avifauna

Peck, Kirsi Marianne January 1989 (has links)
The tree species preferences by six arboreal bird species and their role in structuring the bird communities in woodland were investigated in two sites in County Durham. Each bird species showed a preference or avoidance for most of the tree species in both study sites. The patterns of tree preference were different for each bird species, and were the basis for efficient partitioning of the foraging niches in woodland. Bird species showed significantly less overlap in tree species choice than in any of the other four niche dimensions examined, making it the most important dimension of the foraging niche. The tree species preferences of the bird species were reflected in the distribution of the birds within the woods. For each pair of bird species the degree of similarity in tree species choice and birds' distribution in the wood were identical. Bird species richness was predictable from tree species richness. There were significant positive correlations between all pairs of the following factors: bird species diversity, tree species diversity, bird species richness, tree species richness, bird density, and the percentage of broadleaved trees. Bird density was negatively correlated with the size of the wood (or compartment), apparently due to an edge effect. Seasonal and year to year changes in the tree preference by birds were explicable in terms of changes in the relative abundance of arthropod prey and other foods available in the trees.
2

Grassland birds in California : an investigation into the influence of season, floristic composition, and artificial structures on avian community structure /

Goerrissen, Jan. January 2005 (has links)
Thesis (Ph. D.)--University of California, Davis, 2005. / "June 2005"--Leaf 1. Degree granted in Ecology. Includes bibliographical references. Also available via the World Wide Web. (Restricted to UC campuses)
3

Ptačí společenstva v porostech invazní křídlatky (Reynoutria sp. div.) / Bird communities in the invasive Knotweed (Reynoutria sp. div.)

Hajzlerová, Lenka January 2012 (has links)
Although it is widely recognized that exotic plant invaders can affect diversity of native plant communities, a few studies of natural systems concern about the nature abundance and diversity loss and the associated consequences for higher trophic levels. Little is known impact of exotic riparian plant on higher-order consumers, such as birds. Such is requirement to understand underlying mechanisms of invasive processes and formulating effective management strategies. We examined interaction between invasive knotweed (Reynoutria sp. div., next only knotweed) and bird communities. We recorded occurrence of birds along three rivers in riverbanks that were either dominated by native vegetation or invaded by knotweed. Birds were recorded in breeding seasons in 2011 and 2012 near town Frýdek-Místek and Valašské Meziříčí. We interested especially in (i) how knotweed composition within riparian systems affects avian communities and (ii) what common bird characteristics are influenced by knotweed. Our outcome found positive effect of Marsh Warbler (Acrocephalus palustris) and Great Tit (Parus major) in high knotweed cover and negative effect of Grey Wagtail (Motacilla cinerea). Interspecific comparison common avian characteristics suggest that knotweed invasion can impact avian abundance living in lower...
4

Habitat interactions structuring songbird communities across forest-urban edges

MacDonald-Beyers, Kristi. January 2008 (has links)
Thesis (Ph. D.)--Rutgers University, 2008. / "Graduate Program in Ecology and Evolution." Includes bibliographical references (p. 132-140).
5

Diversity of birds in relation to area, vegetation structure and connectivity in urban green areas in La Paz, Bolivia

Hiding, Camilla January 2012 (has links)
With a   growing human population, cities keep growing worldwide altering ecosystem   and thereby affecting the species living in these areas. Most studies of   urbanization and its effect on ecosystem have been conducted in the western   world and little is known about its effect in the neotropical part of the   world. I examined effects of fragment size, vegetation structure and   connectivity of urban green areas on bird species richness, mean abundance,   diversity and biomass in La Paz, Bolivia. Additionally, the effects of   different disturbance variables on bird community were evaluated. In total,   36 bird species were found in 24 fragment of varying size, connectivity and   level of disturbance. Bird species richness decreased with increasing   disturbance while connectivity and fragment size did not contribute   significantly to explain the variation in species richness at count point scale (p>0.005, multiple linear regression). At fragment   scale, however, species richness increased with fragment sizes,   which has been shown in other studies from neotrophical regions. Variation in   abundance, diversity or biomass could not be explained by connectivity,   fragment size or disturbance.     Furthermore, coverage of construction had a negative effect on species   richness while coverage of bushes and coverage of herbs were negatively   related to biomass and diversity, respectively. The composition of bird   species differed with size and disturbance of the fragments, so that more   omnivorous and granivorous species such as Zonotrichia capensis, Turdus chiguanco and Zenaida auriculata, were present in areas highly affected by human activities. Larger fragments,   less affected by human presence held a larger proportion of insectivorous   species.
6

Comparison of Bird Communities between Secondary Natural Forests and Cryptomeria (Cryptomeria japonica) Plantations

Chang, Ying-Cheng 14 February 2008 (has links)
The purpose of this study is to compare the bird communities between mature secondary forests and Cryptomeria (Cryptomeria japonica) plantations. Bird census was carried out in Teng-jhih National Forest Recreation Area, Kaohsiung county, Taiwan during both breeding season and non-breeding season from March to November in 2007. To compare bird communities between two types of forests, diversity index, evenness index, species richness and densities of bird were calculated. Densities of birds were estimated by variable circular-plot point count method. All birds were classified into 10 assemblage guilds. ANOVA was used to examine whether forest types, breeding season and monthly changes will effect the composition of bird communities. A total of 36 bird species of 19 families were recorded during the study period. All of these species were found in secondary forests, and only 27 of them were observed in Cryptomeria plantations. The results showed that bird diversity, abundance and total densities were higher in secondary forests than those in Cryptomeria plantations, either during breeding season or non-breeding season. Canopy tree species of families, Lauraceae and Fagaceae of the secondary forests which can provide more foods than Cryptomeria, canopy foliage omnivores and woodpeckers were more in secondary forests than in Cryptomeria plantations. On the other hand, the openess of shrubs and understory vegetation in the Cryptomeria plantations, shrub foliage omnivores were more in Cryptomeria plantations than in secondary forests.
7

Effects of oak savanna restoration on avian populations and communities in Illinois, final report

Brawn, Jeffrey D. 22 October 1998 (has links)
Includes bibliographical references (leaves 43-45). / Cover title. "Center for Wildlife Ecology." Also available in print.
8

Breeding strategies and community structure in an assemblage of tropical seabirds on the Lowendal Islands, Western Australia

Nicholson, Lisa January 2002 (has links)
Thesis (Ph. D.)--Murdoch University, 2002. / Includes bibliographical references (p. 311-323).
9

Bird communities and vegetation on Swedish wet meadows : importance of management regimes and landscape composition /

Gustafson, Tomas. Berg, Åke. January 2006 (has links)
Thesis (doctoral)--Swedish University of Agricultural Sciences, 2006. / Errata sheet inserted. Appendix includes reproductions of papers and manuscripts co-authored with Åke Berg. Includes bibliographical references. Issued also electronically via World Wide Web in PDF format; online version lacks appendix of papers.
10

Bird communities and vegetation on Swedish wet meadows importance of management regimes and landscape composition /

Gustafson, Tomas. January 2006 (has links)
Thesis (doctoral)--Swedish University of Agricultural Sciences, 2006. / Title from PDF file as viewed on 11/28/2006. Includes bibliographical references. Also available in print. Print version includes appendices.

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