deborah cushman timothy johnson robert keys, phd department of biology, cornerstone university

Using electronic field recordings to increase the detectability of bird species

at point count sights

Deborah CushmanTimothy JohnsonRobert Keys, PhDDepartment 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

1 2 3 40.3

0.4

0.5

0.6

0.7

0.8

0.9

Observer Detection Accuracy

Series

Perc

enta

ge co

rrec

t det

ectio

ns

P = 0.038P = .010

P = 0.165

Observers vs. EFR

1 2 3 40

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

ObserverRecorder

Series

Perc

enta

ge co

rrec

t det

ectio

ns

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

• Willard and Jessie Pierce Foundation• Pierce Cedar Creek Staff• Cornerstone University• Dr. Robert Keys• Brooke Kiel• Emily Finch

Questions