An acoustic-based method for locating maternity colonies of rare woodland bats
Locating colonies of rare bats can be a time consuming process, as it is often difficult to know where to focus survey effort. However, identifying peaks of bat activity via acoustic monitoring may provide insights into whether a colony is locally present, and help screen out sites with low potentia...
Published in: | PeerJ |
---|---|
Main Authors: | , , , , , , |
Other Authors: | |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
PeerJ
2023
|
Subjects: | |
Online Access: | http://dx.doi.org/10.7717/peerj.15951 https://peerj.com/articles/15951.pdf https://peerj.com/articles/15951.xml https://peerj.com/articles/15951.html |
id |
crpeerj:10.7717/peerj.15951 |
---|---|
record_format |
openpolar |
spelling |
crpeerj:10.7717/peerj.15951 2024-06-02T08:04:05+00:00 An acoustic-based method for locating maternity colonies of rare woodland bats O’Malley, Kieran D. Schofield, Henry Wright, Patrick G.R. Hargreaves, Daniel Kitching, Tom Bollo Palacios, Marina Mathews, Fiona The University of Sussex and Vincent Wildlife Trust 2023 http://dx.doi.org/10.7717/peerj.15951 https://peerj.com/articles/15951.pdf https://peerj.com/articles/15951.xml https://peerj.com/articles/15951.html en eng PeerJ https://creativecommons.org/licenses/by/4.0/ PeerJ volume 11, page e15951 ISSN 2167-8359 journal-article 2023 crpeerj https://doi.org/10.7717/peerj.15951 2024-05-07T14:13:48Z Locating colonies of rare bats can be a time consuming process, as it is often difficult to know where to focus survey effort. However, identifying peaks of bat activity via acoustic monitoring may provide insights into whether a colony is locally present, and help screen out sites with low potential. Using a triage approach, we developed a survey methodology for locating colonies of the woodland-specialist barbastelle bat ( Barbastella barbastellus ). We investigated whether woodland occupancy by a colony could be predicted by acoustic data, and assessed the influence of survey effort (number of acoustic detectors deployed) on detectability. The methodology was then trialled in citizen science surveys of 77 woodlands, with follow-up radio-tracking surveys by specialists being used to confirm presence or absence. Using Receiver Operating Characteristic (ROC) curve analysis, we found that a threshold of four barbastelle passes recorded by at least one detector within one hour of sunset optimised the balance between the true- and false-positive rates. Subsequently, we found that a minimum survey effort of one detector per 6.25 hectares of woodland was needed to ensure a colony would be detected using this threshold, based on a survey sensitivity of 90%. Radio-tracking surveys in a subset of the woodlands, identified as having a high probability of being occupied by a colony based on acoustic monitoring, confirmed the presence of five previously unknown barbastelle maternity colonies. These results demonstrate that a triage system, in which high probability woodland sites are identified based on acoustic survey data, can be used to prioritise sites for future specialist surveys and conservation action. Article in Journal/Newspaper Barbastella barbastellus PeerJ Publishing PeerJ 11 e15951 |
institution |
Open Polar |
collection |
PeerJ Publishing |
op_collection_id |
crpeerj |
language |
English |
description |
Locating colonies of rare bats can be a time consuming process, as it is often difficult to know where to focus survey effort. However, identifying peaks of bat activity via acoustic monitoring may provide insights into whether a colony is locally present, and help screen out sites with low potential. Using a triage approach, we developed a survey methodology for locating colonies of the woodland-specialist barbastelle bat ( Barbastella barbastellus ). We investigated whether woodland occupancy by a colony could be predicted by acoustic data, and assessed the influence of survey effort (number of acoustic detectors deployed) on detectability. The methodology was then trialled in citizen science surveys of 77 woodlands, with follow-up radio-tracking surveys by specialists being used to confirm presence or absence. Using Receiver Operating Characteristic (ROC) curve analysis, we found that a threshold of four barbastelle passes recorded by at least one detector within one hour of sunset optimised the balance between the true- and false-positive rates. Subsequently, we found that a minimum survey effort of one detector per 6.25 hectares of woodland was needed to ensure a colony would be detected using this threshold, based on a survey sensitivity of 90%. Radio-tracking surveys in a subset of the woodlands, identified as having a high probability of being occupied by a colony based on acoustic monitoring, confirmed the presence of five previously unknown barbastelle maternity colonies. These results demonstrate that a triage system, in which high probability woodland sites are identified based on acoustic survey data, can be used to prioritise sites for future specialist surveys and conservation action. |
author2 |
The University of Sussex and Vincent Wildlife Trust |
format |
Article in Journal/Newspaper |
author |
O’Malley, Kieran D. Schofield, Henry Wright, Patrick G.R. Hargreaves, Daniel Kitching, Tom Bollo Palacios, Marina Mathews, Fiona |
spellingShingle |
O’Malley, Kieran D. Schofield, Henry Wright, Patrick G.R. Hargreaves, Daniel Kitching, Tom Bollo Palacios, Marina Mathews, Fiona An acoustic-based method for locating maternity colonies of rare woodland bats |
author_facet |
O’Malley, Kieran D. Schofield, Henry Wright, Patrick G.R. Hargreaves, Daniel Kitching, Tom Bollo Palacios, Marina Mathews, Fiona |
author_sort |
O’Malley, Kieran D. |
title |
An acoustic-based method for locating maternity colonies of rare woodland bats |
title_short |
An acoustic-based method for locating maternity colonies of rare woodland bats |
title_full |
An acoustic-based method for locating maternity colonies of rare woodland bats |
title_fullStr |
An acoustic-based method for locating maternity colonies of rare woodland bats |
title_full_unstemmed |
An acoustic-based method for locating maternity colonies of rare woodland bats |
title_sort |
acoustic-based method for locating maternity colonies of rare woodland bats |
publisher |
PeerJ |
publishDate |
2023 |
url |
http://dx.doi.org/10.7717/peerj.15951 https://peerj.com/articles/15951.pdf https://peerj.com/articles/15951.xml https://peerj.com/articles/15951.html |
genre |
Barbastella barbastellus |
genre_facet |
Barbastella barbastellus |
op_source |
PeerJ volume 11, page e15951 ISSN 2167-8359 |
op_rights |
https://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.7717/peerj.15951 |
container_title |
PeerJ |
container_volume |
11 |
container_start_page |
e15951 |
_version_ |
1800748706088091648 |