1. Video Identification of Nest Predators of Ground-nesting Forest Birds in Southeastern Arizona
© B. Small/VIREO
Chris Kirkpatrick (University of Arizona), Courtney J. Conway (USGS Arizona Cooperative Fish and Wildlife Research Unit), and Moez H. Ali (University of Arizona)

2. Study Site in Santa Catalina Mountains, AZ
Introduction
Nest depredation is the most common cause of reproductive failure for many species of birds
Identity of nest predators unknown for most bird species (including high-elevation forest birds in southeastern Arizona)
Study Site in Santa Catalina Mountains, AZ

3. ? >600 nests of 3 ground-nesting species monitored
~90% of nest failures due to nest predators
No nest depredations observed ?
Potential nest predators: snakes, mammals, or birds?

5. Study Objectives Placed video cameras at 22 nests of ground-nesting
bird species to:
Identify common nest predator species
Determine relative frequency with which predator species depredate nests
Assess whether appearance of nest remains can be used to identify common nest predators

7. Red-faced Warbler (Cardellina rubrifrons)
Orange-crowned Warbler (Vermivora celata)
Yellow-eyed Junco (Junco phaeonotus)

8. Methods Placed camera ~0.5 m from nests
Placed video recorder and battery ~20 m from nests
Checked nests (remotely) every 24 hours
Recorded appearance of nests following depredations
Reviewed video tapes following depredations

9. Results
13 of 22 nests depredated (nesting success = 39% for camera nests, 34% for non-camera nests)
8 nests depredated by gray foxes (Urocyon cinereoargenteus)
5 nests depredated by cliff chipmunks (Tamias dorsalis )
1 nest depredated by Mexican woodrat (Neotoma mexicana)

10. Results Cont.
Foxes and the woodrat depredated nests at night (20: :30)
Chipmunks depredated nests during the day (06:45 - 9:11)
Foxes consumed nest contents rapidly (5-10 sec)
Chipmunks and the woodrat made multiple trips to nests over period of minutes or days

13. Appearance of nest cup and lining following depredations
Results Cont.
Appearance of nest cup and lining following depredations
Nest Predator
Nest
Undisturbed
Disturbed
Gray Fox 5 3
Cliff Chipmunk 2
Mexican Woodrat 1

14. Discussion
Mammals appear to be principal nest predators of ground-nesting birds in the Sky Island mountains
Gray foxes and cliff chipmunk appear to be principal nest predator species
What about snakes (common nest predators elsewhere)?

15. Discussion Cont.
What about using nest remains to identify predator species?
We found substantial variability in appearance of nest remains within and between predator species
Appearance of nest remains should not be used to ID nest predator species

16. Future Research Increase sample size of video camera nests
Identify other nest predator species (e.g., Steller’s jays?)
Expand study area to include lower-elevation forest and woodlands
© J. Culbertson/VIREO

17. Acknowledgments Field Assistants
Dominic LaRoche, Abby Purdy, Eli Rose, Diane Tracy,
Anna Westling-Douglass
Project Support
Susan Sferra, Josh Taiz,
R. L. Peterson, and Y.
Petryszyn
Project Funding
U.S. Bureau of Reclamation
U.S. Geological Survey
University of Arizona