Electronic Theses and Dissertations

Date of Award

1-1-2023

Document Type

Thesis

Degree Name

M.S. in Biological Science

First Advisor

Jason Hoeksema

Second Advisor

Richard Buchholz

Third Advisor

Lainy Day

Relational Format

dissertation/thesis

Abstract

Although the causes of broad population declines of migratory shorebirds are not well understood, it is likely that loss of migratory stopover habitat is a contributing factor. In the Lower Mississippi Alluvial Valley (LMAV), much of the historical stopover sites have been converted to agricultural land. To combat this dearth, we have incentivized farmers to create temporary wetland habitat on shallowly flooded corn and soybean cropland in the LMAV during the fall after harvest. In a two-year study, shorebird surveys were completed bi-weekly on employed farm sites to determine the abundances of shorebirds present on five different temporal flood treatments repeated on four farm sites, and a sister study quantifying chironomid abundance and biomass happened simultaneously to determine associations between bird and invertebrate abundances. Additionally, shorebirds were captured and radio-tagged to determine stopover duration and ultimately total numbers of individual shorebirds visiting during a field season. In the fall, shorebirds were significantly more abundant on actively flooded fields vs dry control, passive, or winter fields. During the winter, abundances were significantly higher on the two active flooded fields than the control, but only the field actively flooded for a longer duration had significantly higher abundances than all other treatments. Shorebirds and chironomids were positively associated across both seasons. Shorebird stopover durations were longer based on our radio data than prior estimates for certain species in the same region, but the cause of this extension is unknown. Based on these results, it is recommended that flooding fields post-harvest in the fall is important for attracting the highest abundances of shorebirds during a time of need. Further, there seems to be a positive implication of flooding early and holding water on a field into the winter. Working cooperatively with farmers can help all involved parties meet their needs most efficiently, and flooding multiple adjacent parcels of land may create the most optimal stopover conditions for shorebirds.

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