Birds, Water, and Saltcedar: Strategies for Riparian Restoration in the Colorado River Delta

Persistent Link:
http://hdl.handle.net/10150/196071
Title:
Birds, Water, and Saltcedar: Strategies for Riparian Restoration in the Colorado River Delta
Author:
Hinojosa-Huerta, Osvel
Issue Date:
2006
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
I evaluated the spatial and temporal patterns of the avian communities in the Colorado River delta, Mexico, and their relationship with vegetation type and surface water. I also developed plausible conservation and restoration guidelines for riparian areas and native birds in the region. The study included monthly point counts at 30 transects (240 points) from May 2002 to July 2003, breeding counts at 175 sites (3 times per year) during 2002 and 2003, and habitat measurements at the survey points.The most common species were Mourning Doves, Red-winged Blackbirds, and Brown-headed Cowbirds, but another 64 species were commonly found, including Verdins, Song Sparrows, Yellow-breasted Chats and Abert's Towhees. Surface water was the most important habitat feature related to avian richness and density regardless of vegetation type or land cover (P < 0.005). During summer, species richness was explained by variations in water and the cover of cottonwoods (r2 = 0.56, P < 0.001), and the variation in bird densities was explained by variations in water and the cover of willows (r2 = 0.35, P = 0.003).When comparing native versus saltcedar dominated sites, both with the presence (wet) or absence (dry) of surface water, the diversity of birds was more influenced by the presence of water than by vegetation type. Bird abundance was more influenced by vegetation type, but water also had an important effect, as wet sites had higher bird abundance than dry sites with the same vegetation type, and saltcedar wet areas had similar avian abundance to native dry sites. On all cases, the presence of water was an important factor determining the ecological value, in terms of avian richness, abundance, and diversity, of both native riparian and saltcedar areas. Saltcedar areas with surface water had avian characteristics similar to native riparian sites.The dedication of instream flows and pulse floods, the maintenance of vegetation cover and structural diversity, and an increase of older riparian stands will secure the viability of existing bird populations and will increase the probability of recovery of the species that are still extirpated from the floodplain of the Colorado River in Mexico.
Type:
text; Electronic Dissertation
Keywords:
avian; Colorado River; cottonwood; floodplain; instream flows; willow
Degree Name:
PhD
Degree Level:
doctoral
Degree Program:
Natural Resources; Graduate College
Degree Grantor:
University of Arizona
Committee Chair:
Shaw, William W.

Full metadata record

DC FieldValue Language
dc.language.isoENen_US
dc.titleBirds, Water, and Saltcedar: Strategies for Riparian Restoration in the Colorado River Deltaen_US
dc.creatorHinojosa-Huerta, Osvelen_US
dc.contributor.authorHinojosa-Huerta, Osvelen_US
dc.date.issued2006en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractI evaluated the spatial and temporal patterns of the avian communities in the Colorado River delta, Mexico, and their relationship with vegetation type and surface water. I also developed plausible conservation and restoration guidelines for riparian areas and native birds in the region. The study included monthly point counts at 30 transects (240 points) from May 2002 to July 2003, breeding counts at 175 sites (3 times per year) during 2002 and 2003, and habitat measurements at the survey points.The most common species were Mourning Doves, Red-winged Blackbirds, and Brown-headed Cowbirds, but another 64 species were commonly found, including Verdins, Song Sparrows, Yellow-breasted Chats and Abert's Towhees. Surface water was the most important habitat feature related to avian richness and density regardless of vegetation type or land cover (P < 0.005). During summer, species richness was explained by variations in water and the cover of cottonwoods (r2 = 0.56, P < 0.001), and the variation in bird densities was explained by variations in water and the cover of willows (r2 = 0.35, P = 0.003).When comparing native versus saltcedar dominated sites, both with the presence (wet) or absence (dry) of surface water, the diversity of birds was more influenced by the presence of water than by vegetation type. Bird abundance was more influenced by vegetation type, but water also had an important effect, as wet sites had higher bird abundance than dry sites with the same vegetation type, and saltcedar wet areas had similar avian abundance to native dry sites. On all cases, the presence of water was an important factor determining the ecological value, in terms of avian richness, abundance, and diversity, of both native riparian and saltcedar areas. Saltcedar areas with surface water had avian characteristics similar to native riparian sites.The dedication of instream flows and pulse floods, the maintenance of vegetation cover and structural diversity, and an increase of older riparian stands will secure the viability of existing bird populations and will increase the probability of recovery of the species that are still extirpated from the floodplain of the Colorado River in Mexico.en_US
dc.typetexten_US
dc.typeElectronic Dissertationen_US
dc.subjectavianen_US
dc.subjectColorado Riveren_US
dc.subjectcottonwooden_US
dc.subjectfloodplainen_US
dc.subjectinstream flowsen_US
dc.subjectwillowen_US
thesis.degree.namePhDen_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineNatural Resourcesen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.chairShaw, William W.en_US
dc.contributor.committeememberShaw, William W.en_US
dc.contributor.committeememberMannan, Williamen_US
dc.contributor.committeememberConway, Courtneyen_US
dc.contributor.committeememberGlenn, Edwarden_US
dc.contributor.committeememberFitzsimmons, Kevinen_US
dc.identifier.proquest1760en_US
dc.identifier.oclc659747518en_US
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