Using roadside surveys to detect short‐eared owls: A comparison of visual and audio techniques

ABSTRACT We piloted a roadside survey technique for detecting short‐eared owls (Asio flammeus) during the courtship period in western Montana, USA. We conducted 33 surveys between 2009 and 2012 and timed surveys to coincide with courtship behavior. Short‐eared owls perform courtship flights and voca...

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Bibliographic Details
Main Authors: Matt D. Larson, Denver W. Holt
Format: Article
Language:English
Published: Wiley 2016-06-01
Series:Wildlife Society Bulletin
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Online Access:https://doi.org/10.1002/wsb.645
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Summary:ABSTRACT We piloted a roadside survey technique for detecting short‐eared owls (Asio flammeus) during the courtship period in western Montana, USA. We conducted 33 surveys between 2009 and 2012 and timed surveys to coincide with courtship behavior. Short‐eared owls perform courtship flights and vocalizations that can be observed and heard during the crepuscular and nocturnal periods. We designed surveys to compare visual and audio survey techniques. Visual surveys occurred during the crepuscular period and were immediately followed by a nocturnal audio‐playback survey. Visual survey techniques accounted for >91% (n = 237) of all detections. Detections associated with audio survey techniques were almost always associated with survey points where ≥1 owl was detected during visual survey. Nearly three‐quarters of visual survey detections (n = 217) occurred between 30 min and 70 min before the end of civil twilight. Greater than 75% of visual survey detections and 90% of audio survey detections occurred in areas where vegetation was uncut, ungrazed, and most frequently associated with vegetation heights greater than approximately 60 cm. We never detected short‐eared owls in areas where livestock was present. We recommend visual surveys during the courtship period as a useful and applicable method for monitoring breeding populations of short‐eared owls. © 2016 The Wildlife Society.
ISSN:2328-5540