1. Use of passive acoustic recordings
to examine interactions of Northern
Spotted Owls (Strix occidentalis)
and Barred Owls (Strix varia)
Matt Hane
Weyerhaeuser NR
Springfield, Oregon
Raptor Research Foundation Conference
Sacramento, California
November 6, 2015

2. Background
• Reliability of traditional survey method
• How does Barred Owl presence affect
Spotted Owl calling behavior?
• Started in early 2014
• Still collecting data

3. Deployment at Five Spotted Owl
Sites
Weyerhaeuser’s Coos Bay Tree Farm

4. Data Collection
• Wildlife Acoustics SM2+
• Two hours at sunrise and sunset
– Start 1.5 hours before sunrise
– Start 0.5 hour before sunset
– Sunrise to sunset every 8th day
• Lots of data

5. Preliminary System Testing
• Sensitivity of the microphones
• Reliable data

6. Range of
detection
Field test early
September 2014
Broadcast calls ~ 100
m
Barred owl pair ~ 200
m
Long Ridge
Lower Cat
Creek

7. Reliable Data
• Equipment failure
– dead batteries
– bad connections /
cables
– memory cards
– Song Meter
components
• Weather related
– Wind and rain

8. Results So Far
2014 2015
• Spotted owl nesting at
four sites
• No spotted owl nesting
• Preliminary work with
Song Scope Recognizers

9. Next Steps
• Continue building suitable recognizers
• Establish a cut off date
• Analyze
• Publish?

10. Thank You