Guam, Mariana swiftlet nest behavior, 2023-2024

The yǻyaguak (Mariana swiftlet; Aerodramus bartschi) is an endangered cave-nesting species historically found on Guam and the southern Mariana Islands, Micronesia. The population on Guam has been severely impacted by the introduction of the brown treesnake (Boiga irregularis). We analyzed nest attendance behavior derived from near-infrared videography at the colonies at Mahlac and Maemong Caves in April 2023 and November 2023, and analyzed telemetry data on bird movement and colony visitation behavior acquired at Mahlac, Maemong and Fachi Caves on April 2023, November 2023 and April-May 2024. This data release consists of three tabular data sets: (1) Guam, Mariana swiftlet nest attendance data, 2023; (2) Guam, Mariana swiftlet breeding stage data, 2023; and (3) Guam, Mariana swiftlet colony flight bout data, 2023-2024.