Identifier

etd-07132015-015315

Degree

Master of Science (MS)

Department

Renewable Natural Resources

Document Type

Thesis

Abstract

Multiple wetland restoration and enhancement techniques are used in Louisiana to combat land loss and provide habitat for waterbirds. We investigated the avian response to three wetland restoration techniques in the Lower Mississippi Bird’s Foot Delta to determine if the different habitat types resulted in differences in the value of edge habitat. Species richness, guild richness, total bird density, bird density by foraging guild, and bird abundance relative to distance from the marsh edge was compared among (i) crevasse splays, a type of sediment diversion which allow the river to build new wetlands, (ii), beneficial use of dredged material marshes, where heavy equipment to create new wetlands from sediments dredged from navigation channels, (iii) marsh terraces, where lighter equipment is used to create strips of edge habitat from sediments dredged from the restoration site, (iv) old edge marshes, representing pre-restoration conditions at degrading marshes, and (v) open water sites. Seasonal bird counts and vegetation surveys were conducted from March 2013 to October 2014 at plots within the Pass a Loutre State Wildlife Management Area and Delta National Wildlife Refuge in Plaquemines Parish, Louisiana, USA. We found bird abundance and diversity differs among the five habitat types during some times of the year, with habitat type and season often having a significant affect on the composition of the avian community. There was a significant relationship between habitat types and environmental factors (p=0.002), and a significant relationship between foraging guilds and environmental factors (p=0.002). Habitat type functions as a useful predictor of guild richness, but alone is not a perfect substitute for environmental variables when identifying the source of all variation in avian community composition. All habitat types studied provided habitat for birds, but were not utilized by all species or foraging guilds equally. We found that old edge marshes supported similar species richness as restored marshes during summer and winter (p<0.05) and open water supported the highest bird density in winter and spring (p<0.05). Any marsh habitat type, however, can be expected to support greater guild and species richness than open water areas during all seasons, but not greater bird density.

Date

2015

Document Availability at the Time of Submission

Release the entire work immediately for access worldwide.

Committee Chair

Nyman, John Andrew

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