Guam, Post-storm Mariana swiftlet colony size and nest counts, 2023

The Yǻyaguak (Mariana Swiftlet; Aerodramus bartschi) is an endangered cave-roosting species native to Guam and southern Mariana Islands, Micronesia. On May 24-25, 2023, Guam was hit by the category-4 Typhoon Mawar, which brought wide-spread destruction to the island. Approximately 6 weeks prior to the typhoon in April 2023 we conducted surveys of the three known colonies of Yǻyaguak at Mahlac, Maemong, and Fachi caves. This April 2023 pre-Mawar survey provided a baseline population estimate prior to Typhoon Mawar’s landfall. In July 2023, we re-surveyed the caves to estimate colony size and assess whether the cave colonies experienced significant declines in the immediate aftermath of the storm. In November 2023, we conducted our regularly [...]