1. Nest survival in experimentally
created snags on a managed forest
landscape
Matthew Hane, Andrew Kroll, Josh Johnson, Mike
Rochelle and Ed Arnett
AOU/COS Conference | Chicago, IL | August 2013

2. Creating snag habitat from live trees can be done
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• Background
• Study Design
• Results
• Final Thoughts

3. Background
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• Transition from naturally
regenerated to intensively-
managed stands
• Deficiencies in snag
numbers and types
• How will adequate types
and numbers of snags be
maintained in upland
areas?

4. 11/9/20154
Background

5. • 2008 through 2010
• Determine rate of avian nest
survival in snags created from
merchantable 2nd growth
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Study Design

6. • Two stage modeling process
o 1st temporal variation
date, date^2, stage, date*stage, constant, global
o 2nd experimental design
year, treatment, density, dispersion, density*dispersion, area
• Logistic exposure method
Shaffer, Terry L. (2004) A unified approach to analyzing nest success.
Auk, 121, 526-540.
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Study Design

7. Yearly weather
variation
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Study Design

8. • "Industrial tree farms are sterile and lifeless, this
particular method is incredibly ecologically
destructive." Juliette Beck, coordinator of the Sierra Club's Stop
Clearcutting Campaign, as quoted in the San Francisco Bay Guardian
Online November 9, 2011
• " … conversion of naturally regenerating stands
to plantations may lower nesting success … " Vander
Haegen and De Graff (1996)
• Sallabanks and Arnett (2001) reviewed bird
forestry relationships.
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Results - Expected

9. Walter & Maguire (2005) Snags, cavity nesting birds, and
silvicultural treatments in western Oregon. Journal of
Wildlife Management, 69, 1578-1591
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Results - Expected
Primary cavity excavators
Chestnut-back chickadee
Downy woodpecker
Hairy woodpecker
Northern flicker
Pileated woodpecker
Red-breasted nuthatch
Red- breasted sapsucker
Secondary cavity excavators
Brown creeper
European starling
House wren
Violet-green swallow

10. 11/9/201510
Results Nest Totals 2008-2010
2008 2009 2010
Total
Failed Successful Failed Successful Failed Successful
CBCH 15 54 39 78 51 59 295
HOWR 9 27 10 41 4 17 108
NOFL 9 12 6 15 8 13 63
PUMA 0 6 5 4 2 3 20
HAWO 1 2 2 1 6
WEBL 2 1 1 4
RBSA 1 1 1 3
NSWO 1 1 2
RBNU 2 2
VGSW 2 2
Total 38 105 60 142 68 93 506
Yearly Success 73% 70% 58% 67%

11. 11/9/201511
Results Chestnut-back chickadee
• Our Study
o Apparent nest success 65%
o Average daily survival 0.989 95%CL: 0.965-
0.996
• Other Studies
o Mahon & Martin (2006) 49%
o Sperry et. al. (2008) 0.976 & 0.984
o Breeding Bird Survey Trend:

12. 11/9/201512
Results House wren
• Our Study
o Apparent nest success 78%
o Period survival 0.72 95%CL: 0.52, 0.85
• Other Studies
o Period survival rate
o Cavities 0.63 – 0.75
o Boxes 0.83
o Breeding Bird Survey Trend:

13. 11/9/201513
Results Northern flicker
• Our Study
o Apparent nest success 64%
o Period survival rate 0.60 95%CL: 0.46, 0.71
• Other Studies
o Apparent nest success
cavities and boxes 41% - 100%
o Period survival rate 0.41 – 0.80
o Breeding Bird Survey Trend:

14. 11/9/201514
Results Purple martin
• Our Study
o Apparent nest success 65%
o Period survival rate 0.70 95%CL: 0.48, 0.84
• Other Studies
o Nest box success 39% - 84%
o Breeding Bird Survey Trend:

15. 11/9/201515
Final Thoughts
• Leaving created snags at a density of ~ 0.5/ha
retains some cavity-nesting bird species
o Up to years 12-15…
• Benefits restricted by rotation age
o Snags must be created from trees growing in unit
o Suitability is also dependent on stand conditions and
landscape context
• Different strategies are required to provide tall
snags

16. 11/9/201516
THANK YOU