Duck nests in Great Salt Lake, Utah wetlands 2019, 2020, and 2021
Data files
Jul 21, 2023 version files 31.33 KB
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Nests_with_Veg_Traits.csv
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README.md
Abstract
Nesting data for ducks in the wetlands of Great Salt Lake, Utah. Nests were located at U.S. Fish and Wildlife Service's Bear River Migratory Bird Refuge and waterfowl management areas operated by the Utah Division of Natural Resources in 2019, 2020, and 2021.
Methods
Nests were located using a modified chain dragging method that allowed us to search the narrow sides of the dams which created the impoundments of the management areas. Nests were monitored throughout the nesting period and fate was determined by observing the egg shells and remains of the nests. Measurements of vegetation and nest traits occurred following the completion of nesting so as not to disturb the incubating hen. We measured the height and variation of the vegetation surface surrounding the nest by creating two transects that intersected perpendicular to each other at the nest site. The first transect ran parallel to the road for 20 m centered at the nest site. The second transect ran from the road to the water's edge of the dam passing through the nest site. At each meter of the two transects, we recorded the height of vegetation. We then calculated the average height (HeightsAve) and standard deviation of height (HeightsSD) of the vegetation patch surrounding the nest. We calculated the overhead concealment (Overhead_Concealment) by counting the corners of a checkerboard that were obscured from 1.5 m above the nest. Lateral concealment (Lateral_Concealment) was calculated by recording the proportion of a Robel pole that was obscured by vegetation at the nest site from 4 m away from each of the 4 cardinal directions and then calculating the averaged concealment. Additionally, we collected the distance from the nest to the edge of the road (Dist_From_Road), the distance from the center of the road to the water's edge (Width_of_Dike), and the height of the tallest vegetation within 1 m of the nest (Tall_Height).