Date of Award
Master of Science in Coastal Marine and Wetland Studies
Coastal and Marine Systems Science
Christopher E. Hill
John J. Hutchens, Jr.
Keith R. Walters
MacGillivray's Seaside Sparrow (Ammodramus maritimus macgillivraii) is a coastal marsh species sensitive to habitat alteration and threatened by coastal wetland loss. Data on seaside sparrow distribution, breeding success, and critical habitats are lacking in South Carolina. To better understand the demographics and incubation behavior of the species, I monitored breeding success, densities, song output, and presence of predators at three 7-hectare plots at the densest known population in the state. I also placed temperature data-loggers in a subset of nests to discern any links between incubation behavior and nest fate. Densities varied from a low of 5 birds/ha in a Juncus-dominated site to an estimated 68 birds/ha in Spartina alterniflora/Distichlis spicata-dominated impoundment. Sparrows built nests at a mean height of 31.1 cm, lower than nests found in Georgia and Florida. Daily nest mortality was low, at 6.9%. Nest height, mean nest temperature, and duration of off-bouts best predicted nest fate. Marsh rice rats (Oryzomus palustris) caused 90% of known nest failures. Females that incubated successful nests had significantly shorter off-bout durations, lower off-bout frequencies, and higher mean nest temperatures than females from unsuccessful nests. Results from thedemographic study suggest that the breeding seaside sparrow population at Tom Yawkey nested more densely when nesting habitat was ideal, and had fairly high productivity compared to breeding populations in nearby states. I was unable to find a significant correlation between habitat variables and seaside sparrow occupancy across 16 random South Carolina sites. Small-scale marsh features may have influenced site occupancy, some remotely sensed landscape feature that was not tested in my study, or a combination of the two.
Laskaris, Yianni P., "Macgillivray's Seaside Sparrow (Ammodramus maritimus macgillivraii) Breeding Biology & Population Density at Tom Yawkey Wildlife Center" (2016). Electronic Theses and Dissertations. 32.