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Full-Text Articles in Life Sciences
Glaucous-Winged Gull Predation On Chicken Eggs Treated With A Uv-Blocking Agent, Athena T. Smith
Glaucous-Winged Gull Predation On Chicken Eggs Treated With A Uv-Blocking Agent, Athena T. Smith
Master's Theses
Egg cannibalism plays a major role in the life histories of Glaucous-winged Gulls (Larus glaucescens) breeding at Protection Island, Washington. Gulls, along with other birds, visualize reflected ultraviolet (UV) light and I wondered if reflected UV light plays a role in determining which eggs are selected for cannibalization. Motivated by studies showing that tree-nesting bird eggs coated with a UV-blocking agent were less subject to predation than control eggs, I tested whether ground-nesting Glaucous-winged Gulls would preferentially predate control chicken eggs over those coated with a UV-blocking agent. Early during five mornings I formed artificial nests at randomly-determined …
West Indian Manatee (Trichechus Manatus) Habitat Characterization Using Side-Scan Sonar, Mindy J. Mclarty
West Indian Manatee (Trichechus Manatus) Habitat Characterization Using Side-Scan Sonar, Mindy J. Mclarty
Master's Theses
In this study, the reliability of low cost side-scan sonar to accurately identify soft substrates such as grass and mud was tested. Benthic substrates can be hard to classify from the surface, necessitating an alternative survey approach. A total area of 11.5 km2 was surveyed with the sonar in a large, brackish mangrove lagoon system. Individual points were ground-truthed for comparison with the sonar recordings to provide a measure of accuracy. Five substrate types were identified: Dense seagrass, sparse seagrass, mangrove soil, mangrove soil with rock, and silt. A zoned benthic substrate map was created from the sonar recordings. …