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

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dc.contributor.advisor Hart, Patrick J. Gallardo Cruz, Karen 2020-02-11T18:33:44Z 2020-02-11T18:33:44Z 2019-12
dc.subject Ecology
dc.subject Acoustics
dc.subject Animal sciences
dc.subject bird vocalizations
dc.subject Hawaii
dc.subject helicopter noise
dc.subject noise pollution
dc.subject songbirds
dc.subject vocal plasticity
dc.title Helicopter noise in Hawaiʻi's protected natural areas changes temporal characteristics of songbird vocalizations
dc.title.alternative Ruido de helicópteros en areas naturales protejidas de Hawaiʻi cambia las características temporales de vocalizaciones de aves
dc.type Thesis M.S.
dc.contributor.department Tropical Conservation Biology & Environmental Science
dcterms.abstract Anthropogenic 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.extent 38 pages
dcterms.language eng
dcterms.publisher University of Hawaii at Hilo
dcterms.rights All 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.type Text
Appears in Collections: Tropical Conservation Biology and Environmental Science
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