Assessment of distribution and abundance estimates for Mariana swiftlets (Aerodramus bartschi) via examination of survey methods

Wilson Journal of Ornithology
By: , and 

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Abstract

We described past and present distribution and abundance data to evaluate the status of the endangered Mariana Swiftlet (Aerodramus bartschi), a little-known echolocating cave swiftlet that currently inhabits 3 of 5 formerly occupied islands in the Mariana archipelago. We then evaluated the survey methods used to attain these estimates via fieldwork carried out on an introduced population of Mariana Swiftlets on the island of O'ahu, Hawaiian Islands, to derive better methods for future surveys. We estimate the range-wide population of Mariana Swiftlets to be 5,704 individuals occurring in 15 caves on Saipan, Aguiguan, and Guam in the Marianas; and 142 individuals occupying one tunnel on O'ahu. We further confirm that swiftlets have been extirpated from Rota and Tinian and have declined on Aguiguan. Swiftlets have remained relatively stable on Guam and Saipan in recent years. Our assessment of survey methods used for Mariana Swiftlets suggests overestimates depending on the technique used. We suggest the use of night vision technology and other changes to more accurately reflect their distribution, abundance, and status.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Assessment of distribution and abundance estimates for Mariana swiftlets (Aerodramus bartschi) via examination of survey methods
Series title Wilson Journal of Ornithology
DOI 10.1676/16-106.1
Volume 130
Issue 1
Year Published 2018
Language English
Publisher Wilson Ornithological Society
Contributing office(s) Forest and Rangeland Ecosystem Science Center
Description 7 p.
First page 23
Last page 29