Estimating density of mountain hares using Distance sampling: a comparison of daylight visual surveys, night-time thermal imaging and camera traps
Surveying cryptic, nocturnal animals is logistically challenging. Consequently, density estimates may be imprecise and uncertain. Survey innovations mitigate ecological and observational difficulties contributing to estimation variance. Thus, comparisons of survey techniques are critical to evaluate...
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2021
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Online Access: | https://pure.qub.ac.uk/en/publications/b1c9f09c-3145-4195-9bd1-6c03ee7a356a https://doi.org/10.2981/wlb.00802 https://pureadmin.qub.ac.uk/ws/files/282407012/wlb.00802_1_.pdf |
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ftqueensubelpubl:oai:pure.qub.ac.uk/portal:publications/b1c9f09c-3145-4195-9bd1-6c03ee7a356a 2024-01-28T10:07:07+01:00 Estimating density of mountain hares using Distance sampling: a comparison of daylight visual surveys, night-time thermal imaging and camera traps Bedson, Carlos P.E. Thomas, Lowri Wheeler, Phillip M. Reid, Neil Harris, W. Edwin Lloyd, Huw Mallon, David Preziosi, Richard 2021-07-05 application/pdf https://pure.qub.ac.uk/en/publications/b1c9f09c-3145-4195-9bd1-6c03ee7a356a https://doi.org/10.2981/wlb.00802 https://pureadmin.qub.ac.uk/ws/files/282407012/wlb.00802_1_.pdf eng eng info:eu-repo/semantics/openAccess Bedson , C P E , Thomas , L , Wheeler , P M , Reid , N , Harris , W E , Lloyd , H , Mallon , D & Preziosi , R 2021 , ' Estimating density of mountain hares using Distance sampling: a comparison of daylight visual surveys, night-time thermal imaging and camera traps ' , Wildlife Biology , vol. 2021 , no. 3 . https://doi.org/10.2981/wlb.00802 Cryptic animals Uplands Survey methods Population monitoring Distance Sampling camera trap Thermal imager /dk/atira/pure/sustainabledevelopmentgoals/life_on_land SDG 15 - Life on Land article 2021 ftqueensubelpubl https://doi.org/10.2981/wlb.00802 2024-01-04T23:21:57Z Surveying cryptic, nocturnal animals is logistically challenging. Consequently, density estimates may be imprecise and uncertain. Survey innovations mitigate ecological and observational difficulties contributing to estimation variance. Thus, comparisons of survey techniques are critical to evaluate estimates of abundance. We simultaneously compared three methods for observing mountain hare Lepus timidus using Distance sampling to estimate abundance. Daylight visual surveys achieved 41 detections, estimating density at 14.3 hares km–2 (95%CI 6.3–32.5) resulting in the lowest estimate and widest confidence interval. Night-time thermal imaging achieved 206 detections, estimating density at 12.1 hares km–2 (95%CI 7.6–19.4). Thermal imaging captured more observations at furthest distances, and detected larger group sizes. Camera traps achieved 3705 night-time detections, estimating density at 22.6 hares km–2 (95%CI 17.1–29.9). Between the methods, detections were spatially correlated, although the estimates of density varied. Our results suggest that daylight visual surveys tended to underestimate density, failing to reflect nocturnal activity. Thermal imaging captured nocturnal activity, providing a higher detection rate, but required fine weather. Camera traps captured nocturnal activity, and operated 24/7 throughout harsh weather, but needed careful consideration of empirical assumptions. We discuss the merits and limitations of each method with respect to the estimation of population density in the field. Article in Journal/Newspaper Lepus timidus mountain hare Queen's University Belfast Research Portal Wildlife Biology 2021 3 |
institution |
Open Polar |
collection |
Queen's University Belfast Research Portal |
op_collection_id |
ftqueensubelpubl |
language |
English |
topic |
Cryptic animals Uplands Survey methods Population monitoring Distance Sampling camera trap Thermal imager /dk/atira/pure/sustainabledevelopmentgoals/life_on_land SDG 15 - Life on Land |
spellingShingle |
Cryptic animals Uplands Survey methods Population monitoring Distance Sampling camera trap Thermal imager /dk/atira/pure/sustainabledevelopmentgoals/life_on_land SDG 15 - Life on Land Bedson, Carlos P.E. Thomas, Lowri Wheeler, Phillip M. Reid, Neil Harris, W. Edwin Lloyd, Huw Mallon, David Preziosi, Richard Estimating density of mountain hares using Distance sampling: a comparison of daylight visual surveys, night-time thermal imaging and camera traps |
topic_facet |
Cryptic animals Uplands Survey methods Population monitoring Distance Sampling camera trap Thermal imager /dk/atira/pure/sustainabledevelopmentgoals/life_on_land SDG 15 - Life on Land |
description |
Surveying cryptic, nocturnal animals is logistically challenging. Consequently, density estimates may be imprecise and uncertain. Survey innovations mitigate ecological and observational difficulties contributing to estimation variance. Thus, comparisons of survey techniques are critical to evaluate estimates of abundance. We simultaneously compared three methods for observing mountain hare Lepus timidus using Distance sampling to estimate abundance. Daylight visual surveys achieved 41 detections, estimating density at 14.3 hares km–2 (95%CI 6.3–32.5) resulting in the lowest estimate and widest confidence interval. Night-time thermal imaging achieved 206 detections, estimating density at 12.1 hares km–2 (95%CI 7.6–19.4). Thermal imaging captured more observations at furthest distances, and detected larger group sizes. Camera traps achieved 3705 night-time detections, estimating density at 22.6 hares km–2 (95%CI 17.1–29.9). Between the methods, detections were spatially correlated, although the estimates of density varied. Our results suggest that daylight visual surveys tended to underestimate density, failing to reflect nocturnal activity. Thermal imaging captured nocturnal activity, providing a higher detection rate, but required fine weather. Camera traps captured nocturnal activity, and operated 24/7 throughout harsh weather, but needed careful consideration of empirical assumptions. We discuss the merits and limitations of each method with respect to the estimation of population density in the field. |
format |
Article in Journal/Newspaper |
author |
Bedson, Carlos P.E. Thomas, Lowri Wheeler, Phillip M. Reid, Neil Harris, W. Edwin Lloyd, Huw Mallon, David Preziosi, Richard |
author_facet |
Bedson, Carlos P.E. Thomas, Lowri Wheeler, Phillip M. Reid, Neil Harris, W. Edwin Lloyd, Huw Mallon, David Preziosi, Richard |
author_sort |
Bedson, Carlos P.E. |
title |
Estimating density of mountain hares using Distance sampling: a comparison of daylight visual surveys, night-time thermal imaging and camera traps |
title_short |
Estimating density of mountain hares using Distance sampling: a comparison of daylight visual surveys, night-time thermal imaging and camera traps |
title_full |
Estimating density of mountain hares using Distance sampling: a comparison of daylight visual surveys, night-time thermal imaging and camera traps |
title_fullStr |
Estimating density of mountain hares using Distance sampling: a comparison of daylight visual surveys, night-time thermal imaging and camera traps |
title_full_unstemmed |
Estimating density of mountain hares using Distance sampling: a comparison of daylight visual surveys, night-time thermal imaging and camera traps |
title_sort |
estimating density of mountain hares using distance sampling: a comparison of daylight visual surveys, night-time thermal imaging and camera traps |
publishDate |
2021 |
url |
https://pure.qub.ac.uk/en/publications/b1c9f09c-3145-4195-9bd1-6c03ee7a356a https://doi.org/10.2981/wlb.00802 https://pureadmin.qub.ac.uk/ws/files/282407012/wlb.00802_1_.pdf |
genre |
Lepus timidus mountain hare |
genre_facet |
Lepus timidus mountain hare |
op_source |
Bedson , C P E , Thomas , L , Wheeler , P M , Reid , N , Harris , W E , Lloyd , H , Mallon , D & Preziosi , R 2021 , ' Estimating density of mountain hares using Distance sampling: a comparison of daylight visual surveys, night-time thermal imaging and camera traps ' , Wildlife Biology , vol. 2021 , no. 3 . https://doi.org/10.2981/wlb.00802 |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.2981/wlb.00802 |
container_title |
Wildlife Biology |
container_volume |
2021 |
container_issue |
3 |
_version_ |
1789334489677168640 |