Bears habituate to the repeated exposure of a novel stimulus, unmanned aircraft systems. Issue 1 (15th January 2019)

• Record Type: Journal Article
• Authors: Ditmer, Mark A; Werden, Leland K; Tanner, Jessie C; Vincent, John B; Callahan, Peggy; Iaizzo, Paul A; Laske, Timothy G; Garshelis, David L
• Editors: Cooke, Steven
• Is Part Of: Conservation physiology. Volume 6:Issue 1(2018)
• Publication Date: 2019-01-15
• Subjects: Drone -- cardiac biologger -- habituation -- stress -- bears -- unmanned aerial system; Nature -- Effect of human beings on -- Periodicals; Conservation biology -- Periodicals; 577.05
• DOI: 10.1093/conphys/coy067
• Languages: English
• ISSNs: 2051-1434

Abstract

Abstract : Drones are powerful new tools used in several biological sciences. Previous work indicated that animals behave fearfully or show a stress response near drone flights. Using heart monitors to gauge stress, we found that bears habituated to drones after ~20 flights over a 3–4-week period and remained habituated. Abstract: Unmanned aircraft systems (UAS; i.e. 'drones') provide new opportunities for data collection in ecology, wildlife biology and conservation. Yet, several studies have documented behavioral or physiological responses to close-proximity UAS flights. We experimentally tested whether American black bears ( Ursus americanus ) habituate to repeated UAS exposure and whether tolerance levels persist during an extended period without UAS flights. Using implanted cardiac biologgers, we measured heart rate (HR) of five captive bears before and after the first of five flights each day. Spikes in HR, a measure of stress, diminished across the five flights within each day and over the course of 4 weeks of twice-weekly exposure. We halted flights for 118 days, and when we resumed, HR responses were similar to that at the end of the previous trials. Our findings highlight the capacity of a large mammal to become and remain habituated to a novel anthropogenic stimulus in a relatively short time (3–4 weeks). However, such habituation to mechanical noises may reduce their wariness of other human threats. Also, whereas cardiac effects diminished, frequent UAS disturbances may have other chronic physiological effects that were not measured. We caution that the rate of habituation may differ between wild and captive animals: while the captive bears displayed large initial spikes in HR change (albeit not as large as wild bears), these animals were accustomed to regular exposure to humans and mechanical noises that may have hastened habituation to the UAS.