Effects of environmental conditions on the use of forward‐looking infrared for bear den detection in the Alaska Arctic
Abstract Industrial off‐road activity in winter overlaps denning habitat of polar bear (Ursus maritimus) and grizzly bear (Ursus arctos) in the North Slope oilfields of Alaska (United States). To prevent disturbance of dens, managers have used forward‐looking infrared (FLIR) cameras to detect dens,...
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ftdoajarticles:oai:doaj.org/article:8a76a08f30064b9d9fd1f9990c3b164e 2023-05-15T14:53:11+02:00 Effects of environmental conditions on the use of forward‐looking infrared for bear den detection in the Alaska Arctic Nils J. Pedersen Todd J. Brinkman Richard T. Shideler Craig J. Perham 2020-07-01T00:00:00Z https://doi.org/10.1111/csp2.215 https://doaj.org/article/8a76a08f30064b9d9fd1f9990c3b164e EN eng Wiley https://doi.org/10.1111/csp2.215 https://doaj.org/toc/2578-4854 2578-4854 doi:10.1111/csp2.215 https://doaj.org/article/8a76a08f30064b9d9fd1f9990c3b164e Conservation Science and Practice, Vol 2, Iss 7, Pp n/a-n/a (2020) FLIR grizzly bear human‐bear conflict polar bear remote sensing unmanned aircraft system Ecology QH540-549.5 General. Including nature conservation geographical distribution QH1-199.5 article 2020 ftdoajarticles https://doi.org/10.1111/csp2.215 2022-12-31T03:57:07Z Abstract Industrial off‐road activity in winter overlaps denning habitat of polar bear (Ursus maritimus) and grizzly bear (Ursus arctos) in the North Slope oilfields of Alaska (United States). To prevent disturbance of dens, managers have used forward‐looking infrared (FLIR) cameras to detect dens, but the effectiveness of FLIR under different environmental conditions is unresolved. Our objective was to evaluate the effects of environmental variables on FLIR‐based techniques for arctic bear den detection. Using a FLIR‐equipped unmanned aircraft system (UAS), we conducted observations of artificial polar bear (APD) and grizzly bear (AGD) dens from horizontal and vertical perspectives between December 2016 and April 2017. We recorded physical characteristics of artificial dens and weather conditions present during each observation. We captured 291 images and classified each as detection or nondetection based on the number of pixels representative of a den “hot spot.” We used logistic regression to model the effects of four weather variables on the odds of detection (detection). We found that UAS‐FLIR detects APDs two times better than AGDs, and that for both species detections are four times more likely from the vertical than horizontal perspective. Lower air temperature and wind speed, and the absence of precipitation and sunlight increased detection for APDs. A 1°C increase in air temperature lowered detection by 12% for APDs and by 8% for AGDs. We recommend that UAS‐FLIR surveys be conducted early in the denning season, on cold, clear days, with calm winds, in the absence of sunlight (e.g., civil twilight). Our study further refines the application of FLIR techniques for arctic bear den detection and offers practical recommendations for optimizing detection. Putative den locations should be confirmed by a secondary method to minimize disturbance as anthropogenic activity continues in the Arctic. Article in Journal/Newspaper Arctic north slope Ursus arctos Ursus maritimus Alaska Directory of Open Access Journals: DOAJ Articles Arctic Conservation Science and Practice 2 7 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
FLIR grizzly bear human‐bear conflict polar bear remote sensing unmanned aircraft system Ecology QH540-549.5 General. Including nature conservation geographical distribution QH1-199.5 |
spellingShingle |
FLIR grizzly bear human‐bear conflict polar bear remote sensing unmanned aircraft system Ecology QH540-549.5 General. Including nature conservation geographical distribution QH1-199.5 Nils J. Pedersen Todd J. Brinkman Richard T. Shideler Craig J. Perham Effects of environmental conditions on the use of forward‐looking infrared for bear den detection in the Alaska Arctic |
topic_facet |
FLIR grizzly bear human‐bear conflict polar bear remote sensing unmanned aircraft system Ecology QH540-549.5 General. Including nature conservation geographical distribution QH1-199.5 |
description |
Abstract Industrial off‐road activity in winter overlaps denning habitat of polar bear (Ursus maritimus) and grizzly bear (Ursus arctos) in the North Slope oilfields of Alaska (United States). To prevent disturbance of dens, managers have used forward‐looking infrared (FLIR) cameras to detect dens, but the effectiveness of FLIR under different environmental conditions is unresolved. Our objective was to evaluate the effects of environmental variables on FLIR‐based techniques for arctic bear den detection. Using a FLIR‐equipped unmanned aircraft system (UAS), we conducted observations of artificial polar bear (APD) and grizzly bear (AGD) dens from horizontal and vertical perspectives between December 2016 and April 2017. We recorded physical characteristics of artificial dens and weather conditions present during each observation. We captured 291 images and classified each as detection or nondetection based on the number of pixels representative of a den “hot spot.” We used logistic regression to model the effects of four weather variables on the odds of detection (detection). We found that UAS‐FLIR detects APDs two times better than AGDs, and that for both species detections are four times more likely from the vertical than horizontal perspective. Lower air temperature and wind speed, and the absence of precipitation and sunlight increased detection for APDs. A 1°C increase in air temperature lowered detection by 12% for APDs and by 8% for AGDs. We recommend that UAS‐FLIR surveys be conducted early in the denning season, on cold, clear days, with calm winds, in the absence of sunlight (e.g., civil twilight). Our study further refines the application of FLIR techniques for arctic bear den detection and offers practical recommendations for optimizing detection. Putative den locations should be confirmed by a secondary method to minimize disturbance as anthropogenic activity continues in the Arctic. |
format |
Article in Journal/Newspaper |
author |
Nils J. Pedersen Todd J. Brinkman Richard T. Shideler Craig J. Perham |
author_facet |
Nils J. Pedersen Todd J. Brinkman Richard T. Shideler Craig J. Perham |
author_sort |
Nils J. Pedersen |
title |
Effects of environmental conditions on the use of forward‐looking infrared for bear den detection in the Alaska Arctic |
title_short |
Effects of environmental conditions on the use of forward‐looking infrared for bear den detection in the Alaska Arctic |
title_full |
Effects of environmental conditions on the use of forward‐looking infrared for bear den detection in the Alaska Arctic |
title_fullStr |
Effects of environmental conditions on the use of forward‐looking infrared for bear den detection in the Alaska Arctic |
title_full_unstemmed |
Effects of environmental conditions on the use of forward‐looking infrared for bear den detection in the Alaska Arctic |
title_sort |
effects of environmental conditions on the use of forward‐looking infrared for bear den detection in the alaska arctic |
publisher |
Wiley |
publishDate |
2020 |
url |
https://doi.org/10.1111/csp2.215 https://doaj.org/article/8a76a08f30064b9d9fd1f9990c3b164e |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic north slope Ursus arctos Ursus maritimus Alaska |
genre_facet |
Arctic north slope Ursus arctos Ursus maritimus Alaska |
op_source |
Conservation Science and Practice, Vol 2, Iss 7, Pp n/a-n/a (2020) |
op_relation |
https://doi.org/10.1111/csp2.215 https://doaj.org/toc/2578-4854 2578-4854 doi:10.1111/csp2.215 https://doaj.org/article/8a76a08f30064b9d9fd1f9990c3b164e |
op_doi |
https://doi.org/10.1111/csp2.215 |
container_title |
Conservation Science and Practice |
container_volume |
2 |
container_issue |
7 |
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1766324611197173760 |