2022–2024 Status and trends of the Palila (Loxioides bailleui)

Hawaii Cooperative Studies Unit Technical Report HCSU-115
By: , and 

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Abstract

Palila (Loxioides bailleui) are critically endangered Hawaiian honeycreepers specializing on the seedpods of māmane (Sophora chrysophylla) and restricted to Mauna Kea volcano on the Island of Hawaiʻi. A previous analysis of survey data estimated an 89% population decline between 1998 and 2021. Using the most recent annual survey data from 2022, 2023, and 2024, we report updated annual population estimates and trends since 1998. The 2022 population estimate was 367–742 birds (point estimate: 545); the 2023 population estimate was 374–842 birds (point estimate: 596); and the 2024 population estimate was 412–970 birds (point estimate: 666). Our estimates for survey years prior to 2022 were within the confidence intervals of the estimates from the previous analysis. Our models likewise showed a population fluctuating between 4,000 and 6,800 birds from 1998 to 2005 (except for an unusually low estimate in 2000), and then a steep decline through 2010. For the next decade, palila abundance fluctuated between 776 and 1,346 birds, before declining again in 2021 to 679 birds. From 1998 to 2024, the population declined by >90% or 203 birds/year, with very strong statistical evidence of an overall downward trend.

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Publication type Report
Publication Subtype State or Local Government Series
Title 2022–2024 Status and trends of the Palila (Loxioides bailleui)
Series title Hawaii Cooperative Studies Unit Technical Report
Series number HCSU-115
Year Published 2025
Language English
Publisher University of Hawai‘i at Hilo
Contributing office(s) Pacific Island Ecosystems Research Center
Description iii, 19 p.
Country United States
State Hawaii
Other Geospatial Island of Hawaii
Additional publication details