Helicopter noise in Hawaiʻi's protected natural areas changes temporal characteristics of songbird vocalizations

Simple item page
dc.contributor.advisorHart, Patrick J.
dc.contributor.authorGallardo Cruz, Karen
dc.contributor.departmentTropical Conservation Biology & Environmental Science
dc.date.accessioned2020-02-11T18:33:44Z
dc.date.available2020-02-11T18:33:44Z
dc.date.issued2019-12
dc.description.degreeM.S.
dc.identifier.urihttp://hdl.handle.net/10790/5235
dc.subjectEcology
dc.subjectAcoustics
dc.subjectAnimal sciences
dc.subjectbird vocalizations
dc.subjectHawaii
dc.subjecthelicopter noise
dc.subjectnoise pollution
dc.subjectsongbirds
dc.subjectvocal plasticity
dc.titleHelicopter noise in Hawaiʻi's protected natural areas changes temporal characteristics of songbird vocalizations
dc.title.alternativeRuido de helicópteros en areas naturales protejidas de Hawaiʻi cambia las características temporales de vocalizaciones de aves
dc.typeThesis
dcterms.abstractAnthropogenic noise has adverse effects on birds, including decreased breeding success, increased flushing behavior, and changes in vocalization patterns. The avifauna in Hawaiʻi is among the most threatened in the world, and helicopter noise in Hawaiʻi’s forests could be another stressor native birds face in addition to disease, habitat loss, and non-native species, but its effect on bird vocalizations has never been assessed. My primary objective was to determine if helicopter noise affects the temporal characteristics of songbird vocalizations within protected natural areas. I placed automated acoustic recorders in three forested areas that are subjected to helicopter traffic from air tours, two in Hawaiʻi Volcanoes National Park and one in the Upper Waiākea Forest Reserve on the Island of Hawaiʻi. I found that songbirds change their vocalization time in response to the power (dB) of approaching helicopter noise. These results indicate that birds are using temporal shifts in vocalizations to mitigate masking effects from helicopter noise. Additionally, I found that the strength and direction of the response is species-specific. Warbling White-eye increased vocalization time, and ‘Apapane and Japanese Bush-warbler decreased vocalization time as helicopter noise power increased, suggesting differences in resilience to helicopter noise between species. Furthermore, results of this study suggest that birds respond the strongest to helicopter noise in areas with very loud and frequent helicopter traffic. My results demonstrate impacts of anthropogenic noise on native bird habitat and may serve as the foundation of an air tour management plan that considers reducing the number of helicopter overflights over protected natural areas to 4 or less helicopters per hour and enforcing a higher flight altitude to decrease power levels of overflights to 191 dB or less.
dcterms.extent38 pages
dcterms.languageeng
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:10175

Files

Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
GallardoCruz_hilo.hawaii_1418O_10175.pdf
Size:
1.16 MB
Format:
Adobe Portable Document Format
Download

Collections

Tropical Conservation Biology and Environmental Science
TCBES Theses