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Contribution to Book
Riparian Bird Population Monitoring in Utah, 1992-2001
Bird Conservation Implementation and Integration in the Americas: Proceedings of the Third International Partners in Flight Conference. 2002 March 20-24; Asilomar, California, Volume 1 (2005)
  • Frank P Howe, Utah State University
  • Russell E Norvell
  • Jimmie R Parrish
Abstract
We report statewide linear and non-linear trends in density from 1992 to 2001 for six common bird species in the riparian areas of Utah. The six species examined here represent over 24 percent of all observations in the period. Four of the six species showed linear declines (Black-headed Grosbeak [Pheucticus melanocephalus], American Goldfinch [Carduelis tristis], American Robin [Turdus migratorius], and Broad-tailed Hum- mingbird [Selasphorus platycercus]) over this period, but the decline in only one species—the Broad-tailed Hummingbird—was considered significant here (F = 19.45, P = 0.002). Yellow Warbler (Dendroica pete- chia) numbers showed the only other significant linear trend, increasing significantly since 1992 (F = 15.30, P = 0.004); Song Sparrow (Melospiza melodia) numbers showed a non-significant increase. A parallel analysis, using Generalized Linear Models to identify non-linear patterns in population trends, showed two apparently consistent patterns of population change with synchro- nous timing of significant trend inflection points. The evaluation of these non-linear patterns, if they persist as additional analyses are competed, will be important to future assessments of Utah’s avian conservation needs. 
Disciplines
Publication Date
2005
Editor
Ralph, C. John; Rich, Terrell D
Publisher
U.S. Dept. of Agriculture, Forest Service, Pacific Southwest Research Station
Series
Gen. Tech. Rep. PSW-GTR-191.
Citation Information
Frank P Howe, Russell E Norvell and Jimmie R Parrish. "Riparian Bird Population Monitoring in Utah, 1992-2001" Albany, CA:Bird Conservation Implementation and Integration in the Americas: Proceedings of the Third International Partners in Flight Conference. 2002 March 20-24; Asilomar, California, Volume 1 (2005) p. 559 - 566
Available at: http://works.bepress.com/frank_howe/17/