Efficacy of aerial forward-looking infrared surveys for detecting polar bear maternal dens.

• Published in: PLOS ONE
• Main Authors: Tom S Smith, Steven C Amstrup, B J Kirschhoffer, Geoffrey York
• Format: Article in Journal/Newspaper
• Language: English
• Published: Public Library of Science (PLoS) 2020
• Subjects: Medicine; R; Science; Q; Ursus maritimus; Alaska
• Online Access: https://doi.org/10.1371/journal.pone.0222744; https://doaj.org/article/bc3399ba23da40119949074d4f5a57e5

Denned polar bears (Ursus maritimus) are invisible under the snow, therefore winter-time petroleum exploration and development activities in northern Alaska have potential to disturb maternal polar bears and their cubs. Previous research determined forward looking infrared (FLIR) imagery could detect many polar bear maternal dens under the snow, but also identified limitations of FLIR imagery. We evaluated the efficacy of FLIR-surveys conducted by oil-field operators from 2004-2016. Aerial FLIR surveys detected 15 of 33 (45%) and missed 18 (55%) of the dens known to be within surveyed areas. While greater adherence to previously recommended protocols may improve FLIR detection rates, the physical characteristics of polar bear maternal dens, increasing frequencies of weather unsuitable for FLIR detections-caused by global warming, and competing false positives are likely to prevent FLIR surveys from detecting maternal dens reliably enough to afford protections consonant with increasing global threats to polar bear welfare.