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Title Page. Evaluating American Oystercatcher Productivity: A Comparison of Nest Success Estimation Methods. Tom Virzi, Ph.D. Candidate Department of Ecology, Evolution and Natural Resources Rutgers, The State University of NJ. Photo: www.birdsbykim.com. Research Objectives.

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  1. Title Page Evaluating American Oystercatcher Productivity: A Comparison of Nest Success Estimation Methods Tom Virzi, Ph.D. Candidate Department of Ecology, Evolution and Natural Resources Rutgers, The State University of NJ Photo: www.birdsbykim.com

  2. Research Objectives • Determine Breeding Habitat Requirements and Causes of Nest Failure • Compare Reproductive Success Between Beach and Marsh Nesting Pairs • Assess the Effects of Human Disturbance on Nest Success Photo: www.birdsbykim.com

  3. Hypotheses • Barrier Beach - Optimal Habitat • Salt Marsh - Sub-Optimal Habitat • Nest Success Lower in Sub-Optimal Habitat • Development/Disturbance on Beaches Pushes Oystercatchers into Sub-Optimal Habitat Photo: www.birdsbykim.com

  4. Methods Methods • Survey beaches, marsh and inlet islands for pairs/nests from March 1 - July 31 • GPS all pairs/nests found • Monitor nests every 3-4 days • Additional data recorded during nest checks: • Point count of gulls • Presence/absence of mammal tracks • Human activity within 100m of nests/territories

  5. Nest Success Estimation Methods • Apparent Nest Success • Biases High • Mayfield Method • Daily Survival Probabilities • Program MARK • Information Theoretic Approach (AIC) • Covariates

  6. Apparent Nest Success Measures • Hatch Success (# Nests Hatched / # Nests Found) • Nest Success (# Nests Fledged / # Nests Found) • DSR – Daily Survival Rate • Nest DSR • Brood DSR • Hatch Success (Nest DSR^28 Days) • Brood Success (Brood DSR^42 Days) • Nest Success (Hatch Success x Brood Success) Nest Success Terms

  7. NJ AMOYs Beach Breeding Pairs in New Jersey North Coast – 8 Pairs Central Coast – 25 Pairs South Coast – 35 Pairs

  8. Study Sites Sites selected over a gradient of human disturbance IB 5 HG 18 SH 10

  9. Holgate Holgate Beach – 23 Pairs Marsh – 3 Pairs Island – 1 Pair Total Pairs – 27 (Beach 2005 – 18)

  10. Stone Harbor Stone Harbor Beach – 19 Pairs Marsh – 11 Pairs Island – 8 Pairs Total Pairs – 38 (Beach 2005 – 20)

  11. Island Beach Island Beach Beach – 5 Pairs Marsh – 11 Pairs Island – 25 Pairs Total Pairs – 41 (Beach 2005 – 5)

  12. Results

  13. Comparison of Nest Success Estimation Methods

  14. Comparison of Nest Success Estimation Methods

  15. Hatch Success ModelsProgram MARK

  16. Brood Success ModelsProgram MARK

  17. Nest Success Rates by HabitatPooled (2005 – 2006)

  18. Nest Success Rates by HabitatPooled (2005 – 2006)

  19. Findings

  20. Findings • Nest success influenced heavily by presence of mammalian predators • Nestling survival may be correlated with interaction between hatch date and gull density • High annual variability in nest success across habitats • Annual variability in flooding • Annual changes in mammal density

  21. What about the effects of coastal development? Development Effect

  22. And human disturbance? Disturbance Effect

  23. CART Modeling • Site-level explanatory model • Habitat characteristics measured in field • GIS layers for development/land use • Landscape-level predictive model • GIS layers only (surrogates) • Test model with statewide surveys on barrier islands and in back bays

  24. Future Research • Modeling Survival in MARK • Increase Banded Population in NJ • Coordinate Band Resighting Efforts with AMOY Working Group • Modeling Nest Success in MARK • Refine Nest Monitoring Methods • Datalogs • Population Viability Analysis

  25. Acknowledgements • Committee Members: • Julie Lockwood, Rutgers University • Rick Lathrop, Rutgers University • David Ehrenfeld, Rutgers University • David Drake, University of Wisconsin • Field Techs: • Mike Ferguson • Steve Grodsky • Patti Rendo • Sheryl Senczakiewicz • NJDFW - Endangered & Nongame Species Program: • Dave Jenkins • Todd Pover • Chris Kisiel • Kathy Clark • Larry Niles, Conserve Wildlife • USFWS - Forsythe National Wildlife Refuge • NJ Division of Parks & Forestry – Island Beach State Park • The American Oystercatcher Working Group • Humphrey Sitters, International Wader Study Group • Jim Merritt, NJDFW - Program Director, Sedge Island Natural Resource Education Center • David Lapuma, Rutgers University

  26. Kristen AND Kristen for spending countless hours in the field with me over the past two years watching oystercatchers

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