Transcript Cushman and Johnson - Sara Parr Syswerda

Using electronic field recordings to
increase the detectability of bird species
at point count sights
Deborah Cushman
Timothy Johnson
Robert Keys, PhD
Department of Biology, Cornerstone University
http://www.flickr.com/photos/mudhen/8591467174/
Introduction
• Monitoring of bird
populations is important in
light of environmental
changes
• Point counts are commonly
used monitoring method
• Limitations of point counts
include misidentification,
training, and missed species
Objectives
• We hypothesize that electronic field recordings
(EFR) will show that certain bird species are often
less detectable in field point counts, but that
training can increase the ability of observers in
the detection of these missed species.
• We predict that observer detectability will
increase significantly with each point count series
when EFRs are used.
• EFR’s will enable observers to increase detection
of bird species having lower detection probability
Methods
• Pierce Cedar Creek Institute, Barry County,
Michigan
– 32 Points count sites
– 6 Replicates
– Multiple habitats
• Equipment
– Zoom H4n Field Recorder
– 2 ME62 Sennheiser Omnidirectional
Microphones
• Point counts
– 5 minutes
– Radius < 75 meters
• Analysis of EFR
– Raven Pro 1.5
Results
• Partially completed analysis of four series
• Significant increases in observer accuracy
Observer Detection Accuracy
Percentage correct detections
0.9
0.8
P = 0.165
0.7
P = .010
P = 0.038
0.6
0.5
0.4
0.3
1
2
3
Series
4
Observers vs. EFR
1
0.9
0.8
Percentage correct detections
0.7
0.6
0.5
Observer
Recorder
0.4
0.3
0.2
0.1
0
1
2
3
Series
4
Conclusion
• Our current analysis shows that the use of
electronic field recordings can increase the
detectability rate of field recorders at point
count sites.
Where do we go from here?
• Complete point count series 5 and 6
• Analysis of detectability accuracy
• Analysis of low detection bird species
Acknowledgements
•
•
•
•
•
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Willard and Jessie Pierce Foundation
Pierce Cedar Creek Staff
Cornerstone University
Dr. Robert Keys
Brooke Kiel
Emily Finch
Questions