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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

Breeding Bird Communities of Major Mainland Rivers of Southeastern Alaska

Johnson, Jim A. 01 May 2003 (has links)
Because of the scarcity of information for bird communities at the major mainland rivers of southeastern Alaska, the main objective of this study was to provide baseline information including distribution, status, and habitat associations of breeding birds. I conducted a meta-analysis of all known reports (including the current study) conducted at major mainland rivers during the breeding season. I described bird species composition, distribution, abundance estimates, status, habitat associations, and guild membership for all birds recorded at 11 major mainland rivers. Based on incidental observations, 170 species were recorded by all studies. Of these, 134 species were known or suspected to breed, accounting for 50% of all birds known from Alaska and 80% of all birds known from southeastern Alaska. In addition, I provided information on species of management concern as well as management implications and recommendations. I used point counts to survey birds within deciduous riparian vegetation at 6 major mainland rivers during 2000-2002. I compared bird species composition, abundance, richness, and diversity among four main vegetation types of deciduous riparian vegetation: shrubland, young deciduous forest, mature deciduous forest, and mixed deciduous-coniferous forest. Species richness was similar among all habitat types; however, relative abundance and diversity of birds was highest in mixed forest stands. Mature forests had the greatest number of species associated with the Canadian interior. I also used point counts to compare bird species composition, abundance, richness, and diversity among 6 major mainland rivers consisting of three trans-mountain and three coastal rivers. Latitude, connectivity, and availability of mature and mixed forests were the major factors thought to cause differences in bird communities among rivers. Contrary to our predictions, coastal rivers had higher bird species richness, diversity, point abundance , and point richness than trans-mountain rivers. Of the 10 species associated with the Canadian interior recorded during point counts, 8 occurred at both trans-mountain and coastal rivers.

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