2021 Tinian Island forest bird abundance estimates

Hawai‘i Cooperative Studies Unit Technical Report 105
By: , and 

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Abstract

The U.S. Navy, through Micronesian Environmental Services, surveyed landbirds in the Military Lease Area on Tinian Island in May and June 2021 using point-transect distance sampling methods. There were 2,074 individuals of 14 species detected during 123 point counts. Six species were detected during >50% of the counts and were observed at relatively high abundances, while eight species occurred at <50% of the counts and were uncommon to rare. Densities of native landbirds in the Military Lease Area ranged from the uncommon Mariana kingfisher (Todiramphus albicilla) at 0.46 birds/ha (95% confidence interval [CI] = 0.33–0.63) to the very abundant bridled white-eye (Zosterops conspicillatus) at 102.63 birds/ha (95%CI = 86.70–122.91). Most distances recorded during the 2021 Military Lease Area survey were rounded to distance intervals of 0 and 5. Measuring exact distances of detected animals is preferable to collecting distances grouped into bins or rounding. Direct comparison with previously published estimates was not possible because of changes in the sampling frame; however, densities of six species were greater, two were smaller, and one was similar to the 2008 survey estimates for the Hagoi, Diablo, and Masalog regions. Our findings indicate that the landbird community in the Military Lease Area appears to be dynamic and resilient.

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Publication type Report
Publication Subtype Organization Series
Title 2021 Tinian Island forest bird abundance estimates
Series title Hawai‘i Cooperative Studies Unit Technical Report
Series number 105
Year Published 2022
Language English
Publisher Hawai`i Cooperative Studies Unit, University of Hawai`i at Hilo
Contributing office(s) Pacific Island Ecosystems Research Center
Description iii, 19 p.
Country Northern Mariana Islands
Other Geospatial Military Lease Area, Tinian Island
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