~ Soundscape Ecology – Describes the relationship between the landscape and the composition of its sound (Pijanowski et al. 2011)
- Biophony – biotic sounds
- Geophony – geophysical sounds
- Anthrophony – anthropogenic sounds
~ Can visualize the soundscape by using a spectrogram
- Anthrophony is a relatively new addition to the soundscape
~ Animals respond to anthrophony
- Noise changes bird communities and disrupts predator-prey interactions (Francis et al. 2009)
- Noise affects vocalization dynamics of birds
· Songs louder and more repetitive (Pieretti and Farina 2013)
- Aircraft noise increases stress behavior in individual bird species
· Ducks, seabirds, owls, hawks, and eagles exhibited increased stress and agonistic behavior in response to aircraft noise (Andersen et al. 1989, Conomy et al. 1998, Brown 1990, Delaney et al. 1999, Goudie & Jones 2004)
· Bald Eagles responded most often to helicopters in comparison to jets and light planes (Grubb and Bowermann 1997)
~ Helicopter traffic is plentiful on the Big Island
- Before eruption, a lot of flights over native forest at Hawaii Volcanoes National Park (HAVO) to get to Pu’u O’o
- Helicopters would often fly low over the forest. Have seen them <100ft above canopy
· Low-flying helicopters are loud
A huge mahalo to my committee members, Patrick Hart, Kristina Paxton, Matthew Knope and Bryan Pijanowski; to all the people who helped me in the field, Jeff Wood, Barret Baca, Victor and Edgar Noguera, Leonard Munstermann; to everyone at Hawaii Volcanoes National Park and the National Park Service Natural Sounds and Night Skies Division for their funding, field access, and help: Danielle Foster, Ashley Pipkin, Kurt Fristrup, Serafina Gajate, and the HAVO Mule Packing Program; and to Scott Jorgensen from Blue Hawaiian Helicopters for his input on site selection.
Does helicopter noise affect the vocalizing behavior of native and non-native birds at HAVO?
- Predict that helicopter noise will negatively impact the vocalizing behavior of birds at HAVO.
- The results of this research will inform the creation of an air tour management plan for HAVO
- First study to quantify the effect of noise on Hawaiian birds
- One of few studies to examine the effect of noise on an entire bird community
Audio Recording Methods
~ Passive acoustic recorders – during March, April & beginning of May
- Recorded continuously between 7 am - 5 pm
~ Placed recorders 90 m apart from each other to ensure recorder independence
Which helicopter noise characteristics have the most effect on the amount of time birds spend vocalizing?
- Prediction: Frequency range and Average Power of helicopter noise will have the greatest effect on the amount of time birds spend vocalizing.
Acoustic Analysis Methods
~ To measure noise characterisics:
- For 10 seconds every 20 seconds, measured Delta Frequency (kHz) and Average Power (dB) of helicopter noise
~ To measure bird characteristics
- For 10 seconds every 20 seconds, measured total vocalization time, separated by species
Statistic Analysis Methods
Linear Mixed Model
- Response Variable: total vocalization time (s) by species
- Explanatory Variable: frequency range (Hz) of noise, average power of noise (dB), species
- Random Factor: site
Relationship Between Vocalization Time and Noise Characteristics Differs Between Species
Helicopter Noise Frequency Results
With increasing helicopter noise:
~ Japanese White-eye vocalization time increased
~ No relationship between vocalization time and frequency of noise for and ʻŌmaʻo , ʻApapane, Hawaiʻi ʻAmakihi and Japanese Bush-warbler
Helicopter Noise Power Results
With increasing helicopter noise:
~ Japanese White-eye vocalization time decreased
~ Hawaiʻi ʻAmakihi vocalization time increased
~ No relationship between vocalization time and noise power for Japanese Bush-warbler, ʻŌmaʻo, and ʻApapane
~ Response to helicopter noise differs between bird species
~ Hawaii ʻAmakihi and Japanese White-eye seem to be the most responsive to helicopter noise from preliminary data
~ Other bird species may not be responding because habituation may have already taken place, or they are more resilient to helicopter noise
~ In addition to the question presented, I will also address:
- Do individual bird species vocalize more prior to the presence of helicopter noise?
- Does the entire bird community vocalize more prior to the presence of helicopter noise?
- Have birds in areas of high helicopter traffic become habituated to helicopter noise?
~ Expand study to include new recording locations to get a broader representation of how these bird species respond to helicopter noise in other parts of the island
Andersen D.E., O.J. Rongstad and W.R. Mytton. 1989. Response of nesting Red-tailed Hawks to helicopter overflights. The Condor 91:296–299.
Brown AL. 1990. Measuring the Effect of Aircraft Noise on Seabirds. Environment International 16:587–592.
Conomy J.T., J.A. Dubovsky, J.A. Collazo and W.J. Fleming. 1998. Do black ducks and wood ducks habituate to aircraft disturbance? The Journal of Wildlife Management 62:1135–1142.
Delaney D.K., T.G. Grubb, P. Beier, L.L. Pater and M.H. Reiser. 1999. Effects of helicopter noise on Mexican Spotted Owls. The Journal of Wildlife Management 63:60–76.
Francis CD, Ortega CP, Cruz A. 2009. Noise Pollution Changes Avian Communities and Species Interactions. Current Biology 19:1415–1419.
Grubb TG, Bowerman WW. 1997. Variations in breeding bald eagle responses to jets, light planes and helicopters. j. Raptor Res 31:213–22.
Goudie R.I. and L.I. Jones. 2004. Dose-response relationships of harlequin duck behaviour to
noise from low-level military jet over-flights in central Labrador. Environmental Conservation 31:289–298.
Pieretti N., A. Farina, D. Morri. 2011. A new methodology to infer the sienging activity of an avian community: The Acoustic Complexity Index (ACI). Ecological Indicators 11:868–873.
Pijanowski BC, Farina A, Gage SH, Dumyahn SL, Krause BL. 2011. What is soundscape ecology? An introduction and overview of an emerging new science. Landscape Ecology 26:1213–1232.