Signal Interactions Between Native and Introduced Forest Birds of Hawaiʻi Island and Predicting Distance of Signals from Their Energy

dc.contributor.advisorHart, Patrick J.
dc.contributor.authorHunt, Noah James
dc.contributor.departmentTropical Conservation Biology & Environmental Science
dc.date.accessioned2024-01-25T19:41:04Z
dc.date.available2024-01-25T19:41:04Z
dc.date.issued2023-12
dc.description.degreeM.S.
dc.identifier.urihttps://hdl.handle.net/10790/42738
dc.subjectBiology
dc.subjectacoustic niche hypothesis
dc.subjectacoustic overlap
dc.subjectdensity estimation
dc.subjectdistance-power relationship
dc.subjectpopulation monitoring
dc.subjectsignal partitioning
dc.titleSignal Interactions Between Native and Introduced Forest Birds of Hawaiʻi Island and Predicting Distance of Signals from Their Energy
dc.typeThesis
dcterms.abstractPassive acoustic monitoring using autonomous recording units (ARUs) offers uniqueopportunities to investigate both theoretical and applied ecological questions. I used Song Meter SM4s to answer: (1) whether native and introduced birds in Hawaiʻi are dividing acoustic space in time and frequency, and (2) whether wildlife managers can improve their density estimates of bird species by achieving unbiased distance measurements from ARUs. First, using recordings I collected from a diversity of vegetation types, I compared the observed overlap between introduced and native bird vocalizations from what was expected under a null model of 500 vocalization randomizations. I found that overlap did not differ from the null distribution and was unaffected by community composition nor vegetation type, suggesting that introduced birds are not having a strong impact on native forest bird communication. Second, using field recordings collected while observing vocalizing birds, I modeled distances between birds and the ARUs, measured from range finders as a function of the random effects of maximum power level (amplitude) of bird vocalizations, the orientation of the bird to the microphone, and wind and rain levels, with the species and call type as fixed effects. Overall, there was no strong relationship between distance and any of the random effects. However, when modeling within individual call types, I found four call types among four species showing relationships between distance and sound power level, suggesting that while this method has potential for wildlife monitoring, it requires further refinement.
dcterms.extent54 pages
dcterms.languageen
dcterms.publisherUniversity of Hawaii at Hilo
dcterms.rightsAll UHH dissertations and theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission from the copyright owner.
dcterms.typeText
local.identifier.alturihttp://dissertations.umi.com/hilo.hawaii:10248

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