Behavioral responses of blue-winged teal and northern shoveler to unmanned aerial vehicle surveys

PLoS One. 2022 Jan 19;17(1):e0262393. doi: 10.1371/journal.pone.0262393. eCollection 2022.

Abstract

Unmanned aerial vehicles (UAVs) have become a popular wildlife survey tool. Most research has focused on detecting wildlife using UAVs with less known about behavioral responses. We compared the behavioral responses of breeding blue-winged teal (Spatula discors) (n = 151) and northern shovelers (Spatula clypeata) (n = 46) on wetlands flown over with a rotary DJI Matrice 200 quadcopter and control wetlands without flights. Using a GoPro camera affixed to a spotting scope, we conducted focal individual surveys and recorded duck behaviors for 30 minutes before, during, and 30 minutes after UAV flights to determine if ducks flushed or changed in specific activities. We also conducted scan surveys during flights to examine flushing and movement on the entire wetland. Between 24 April and 27 May 2020, we conducted 42 paired (control and flown) surveys. Both teal and shovelers increased proportion of time engaged in overhead vigilance on flown wetlands from pre-flight to during flight (0.008 to 0.020 and 0.006 to 0.032 of observation time, respectively). Both species left the wetland more frequently during flights than ducks on control wetlands. Despite similarities between species, we observed marked differences in time each species spent on active (e.g., feeding, courtship, swimming), resting, and vigilant behaviors during flights. Overall, teal became less active during flights (0.897 to 0.834 of time) while shovelers became more active during this period (0.724 to 0.906 of time). Based upon scan surveys, ducks flushed in 38.1% of surveys while control wetlands only had a single (2.4%) flush during the flight time. We found launch distance was the most important predictor of whether ducks swam for cover or away from the UAV which could result in inaccurate counts. Ducks appear aware of UAVs during flights, but minimal behavioral shifts suggest negative fitness consequences are unlikely.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Animals, Wild
  • Behavior, Animal / physiology*
  • Ducks
  • Environmental Monitoring / methods*
  • Unmanned Aerial Devices / ethics*
  • Wetlands

Grants and funding

Ducks Unlimited, Inc (S.N.E.), UND College of Arts and Sciences State Critical Needs Award (S.N.E.), UND College of Arts and Sciences Creative Activity Award (S.N.E.), and Research North Dakota Award 19-11-G-229 from the North Dakota Department of Commerce (S.N.E.), and UND Biology Department's Game Management Scholarship (M.D.R.), UND Biology Department's Research Fund (S.N.E.). The funder, Ducks Unlimited, Inc. provided support in the form of salaries for authors K.K. and through a grant to the University of North Dakota for graduate student M.D.R., but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific roles of these authors are articulated in the ‘author contributions’ section.