Managing wetlands and rice to improve habitat for shorebirds and other waterbirds

Transcription

1 Managing wetlands and rice to improve habitat for shorebirds and other waterbirds Matthew E. Reiter Point Blue Conservation Science Wetland Management Workshop Sacramento National Wildlife Refuge May 9, 2014 Photos by PRBO and S. McKay

2 Acknowledgments Khara Strum Catherine Hickey Kristin Sesser Blake Barbaree Mike Wolder Jennifer Isola CVJV California Rice Commission Dennis Jongsomjit Rodd Kelsey Mark Reynolds Sam Veloz Matt Merrifield Monica Iglecia Michelle Reynolds Nat Seavy Tom Gardali Greg Golet Nathan Elliott Rice growers Anonymous donor

3 What is a shorebird? Sandpipers Recurvs : Stilts & Avocets

4 Background Sacramento Valley is a site of international importance for shorebirds in the Western Hemisphere Millions of shorebirds use the region >90% wetlands lost Tens of thousands of acres of wetland habitat restored Managed wetlands and flooded agriculture are important for shorebird populations

5 Background cont d Lots of great rice research. Sustainability of post-harvest flooded rice is uncertain. What about the effectiveness of wetland restoration and management for shorebirds? Better understanding of how to better time habitat delivery across guilds

6 Objectives When is habitat needed? How/What should be implemented? How did we do?

7 When?

8 Objectives: Where is the water? 1. Quantify distribution of water and factors that influence this particularly drought. 2. Identify hotspots of change in water over time.

9 Water Time Series

10 Temporal Change 2000 to 2011 Declining summer and fall 1-3% per year

11 Effect of Drought The number of drought years in the last three water years has significant negative effect on open surface water. Drought = 1 23% decline Parameter Month Estimate Lower 95% CI Upper 95% CI DI 4 July August September

12 Wetland Connectivity for Shorebirds during Migration and Winter Do birds move between geographic regions? Klamath to Sac to San Joaquin? Which habitats do these birds use and when? What does this tell us about the importance of wetlands?

13 Dowitchers use refuge and wetlands during fall migration in Sac Valley

14 Where are Dunlin during the day, and night in late winter? Dunlin used both habitat types until rice was mostly dry Dunlin used rice until it was completely dry

15 Late winter movements Late-January 2014 Late-March 2014 Shift in mid-march 2013 Shift in mid-february 2014

16 When? Fall and spring are critical and need more habitat Drought threatens fall and late winter / spring water availability Winter-flooded rice is unstable habitat and affected by drought which results in large bird movements during late winter

17 How? Early Winter Analysis (Reiter et al. In Review) Type matters Seasonally flooded marsh and summer water selected over vernal pools, alkali meadows, watergrass, permanent ponds, and unmanaged wetlands Size matters >30ha to see large increase in abundance Seasonally Flooded Marsh (ha)

18 How? Early Winter Analysis (Reiter et al. In Review) Topography matters wetlands with gradual transition to upland used more than wetlands with hard levees

19 How? - Depth Strum et al (rice) Variation by guild Shuford et al (corn) Variation in water depth increases species richness

20 How? Vary drawdown timing (rice) Wolder et al. (2010) - wetland

21 How? Cover type / flooding regime matters Size matters >30ha Water depth matters <10cm Vegetation matters more open = better Timing matters

22 How did we do? Multi-scale evaluation needed given mobility of shorebirds

23 How did we do? Pacific Flyway Shorebird Survey and Central Valley Coordinated monitoring program of wetland-dependent shorebird populations in the Pacific Flyway to quantify: 1. Long-term trends 2. Habitat associations 3. Effectiveness of management and conservation actions (iterative learning and adaptive management)

24 Pacific Flyway Shorebird Survey Volunteer driven Pacific Coast of North America Contributes to Migratory Shorebird Project (11 nation coordinated monitoring)

25 Sampling the Central Valley 63 transects surveyed by 24 volunteers

26 Rapid Data Centralization California Avian Data Center 1. Location & Date 2. Survey Conditions 3. Bird Observations 4. Data Review

27 How did we do?? Data Summaries Data Mapping /multimap/pfss/index.php

28 Summary Wetlands and flooded agriculture are important. Maximize value by matching management actions to time with greatest need. Wetland size, location, topography, and water depth all must be considered when targeting shorebird management in wetlands. Research needed on optimizing habitat availability across waterbird groups and flooding regimes. Tracking effectiveness of management is essential for increased success.

29 Thank you and Questions