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22 results on '"Shonfield, Julia"'

2. Audio data compression affects acoustic indices and reduces detections of birds by human listening and automated recognisers

Author

MacPhail, Alexander G., Yip, Daniel A., Knight, Elly C., Hedley, Richard, Knaggs, Michelle, Shonfield, Julia, Upham-Mills, Emily, and Bayne, Erin M.

Abstract

ABSTRACTIncreasing popularity in passive acoustic monitoring and the ease with which researchers can accumulate large quantities of acoustic data has resulted in challenges for audio recording storage, archiving, and management. Reductions in file size can be achieved by lowering sample rate and compressing to different formats; however, how these processes affect audio data quality, and the resulting interpretation of wildlife data is not well understood. We investigated the effect of sampling rate and lossy compression of audio recordings to MP3 from their native WAV format on the performance of four commonly applied avian bioacoustic applications: community listening, distance estimation, automated recognition, and acoustic indices. Compression to MP3 decreased the number of detections, including a reduction in total abundance of individuals when transcribing audio files for community listening and lower precision and recall for automated recognisers. Sampling rate reduction introduced systematic bias to acoustic indices and had an influence on precision and recall for recognisers as well. We recommend against the use of MP3 compression to reduce file volume and suggest other lossless forms of audio compression where an exact copy of the original recording can be recovered.

Published
2024
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7. Weak support for cumulative effects of industrial disturbance on three owl species in Alberta's boreal forest.

Author

Shonfield, Julia and Bayne, Erin M.

Abstract

Copyright of Avian Conservation & Ecology is the property of Resilience Alliance and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Published
2023
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16. Spatial distribution of the Boreal Owl and Northern Saw-whet Owl in the Boreal region of Alberta, Canada.

Author

Domahid, Zoltan, Shonfield, Julia, Nielsen, Scott E., Spence, John R., and Bayne, Erin M.

Abstract

Copyright of Avian Conservation & Ecology is the property of Resilience Alliance and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Published
2019
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19. Territorial defence behaviour and a test of the mechanism of kin recognition in red squirrels

Author

Shonfield, Julia and McAdam, Andrew G.

Subjects
red squirrels, aggressive, behavior and behavior mechanisms, otorhinolaryngologic diseases, mechanism of kin recognition, territorial calls, sense organs, territorial defence behaviour, behavioral disciplines and activities, health care economics and organizations
Abstract

I investigated territorial defence behaviour and tested the mechanism of kin recognition in red squirrels ('Tamiasciurus hudsonicus ') using playbacks of territorial calls. Red squirrels did not discriminate between the calls of kin and non-kin despite previous evidence that they are capable of recognizing kin through territorial vocalizations. I suggest that changes in environmental conditions might have altered the costs and benefits of differential treatment of kin, resulting in a lack of discrimination. Also, red squirrels were no more aggressive in response to playback calls from non-neighbours than from neighbours. Additional playback trials with territorial calls where the frequency was altered suggested that fundamental frequency is the important acoustic component for kin recognition. Variation in territorial defence was evident in red squirrels and call rates increased as the number of surrounding conspecifics increased, indicating that red squirrels adjust territorial defence in response to intruder pressure.

Published
2010

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