Using High Resolution Satellite and Telemetry Data to Track Flooded Habitats, Their Use by Waterfowl, and Evaluate Effects of Drought on Waterfowl and Shorebird Bioenergetics in California

Open-File Report 2020-1102
Prepared in cooperation with the Southwest Climate Adaptation Science Center of the U.S. Geological Survey and the Regional Inventory and Monitoring Program of the U.S. Fish and Wildlife Service
By: , and 


  • Document: Report (17 MB pdf) , XML
  • Data Release: Data Release - Classification of waterfowl habitat and quantification of interannual space use and movement distance from primary roosts to night feeding locations by waterfowl in California for October–March of 2015 through 2018
  • Download citation as: RIS | Dublin Core


Wetland managers in the Central Valley of California, a dynamic hydrological landscape, require information regarding the amount and location of existing wetland habitat to make decisions on how to best use water resources to support multiple wildlife objectives, particularly during drought. Scientists from the U.S. Geological Survey Western Ecological Research Center (WERC), Point Blue Conservation Science (Point Blue), and the U.S. Fish and Wildlife Service (USFWS) partnered to learn how wetland and flooded agricultural habitats used by waterfowl and shorebirds change during the non-breeding season (July–April) particularly during drought. During extreme drought conditions, the ability to provide sufficient water for wildlife often depends on the timing of water deliveries to managed wetlands and winter-flooded crop fields and decisions on whether to fallow croplands. Waterfowl and shorebirds could be particularly affected by these decisions because they typically rest and feed in flooded habitats. Poor habitat conditions resulting from spatially or temporally suboptimal water deliveries (that is, mismatch between waterfowl habitat needs and timing and location of flooded habitats) could reduce waterfowl hunting opportunities and body condition. Point Blue scientists developed a system for near real-time tracking of habitats used by waterfowl, shorebirds, and some other wetland-dependent “waterbirds” ( and to assess the impacts of drought on habitat availability and on waterfowl and shorebird bioenergetics. The WERC researchers linked these data with near real-time tracking (telemetry) data of duck locations throughout the Valley. The team used these two datasets to relate duck locations to open-water characteristics and to learn how waterfowl use habitats under spatially and temporally changing conditions during drought and non-drought periods. We found that recent extreme drought (2013–15) significantly changed the timing and magnitude of flooding and consequently reduced the availability of habitats used by waterfowl and shorebirds more than other recent historic droughts 2000–11. Drought reduced irrigations of moist soil seed plants and thus there was lower food energy available for waterfowl. Analyses using bioenergetics models indicated that, overall, extreme drought increased food energy deficits (total number of deficit days) for shorebirds and waterfowl. Our analysis indicated a strong direct relationship between duck locations and classified habitat derived from open-water data during the wintering period (October–March). This result helps confirm the application of dynamic water data to identify flooded areas that provide waterfowl habitat. Presence of open water at a 1-hectare resolution can be used effectively to identify flooded landscape areas available as habitat for ducks. Our discoveries from evaluating use of space by ducks also indicated that nighttime feeding locations of ducks were concentrated nearby primary roosts and that foraging distances could depend on hydrologic dynamics of location (Suisun Marsh versus California excluding Suisun Marsh) and time of season (early, middle, late). Other results indicated that some areas on the California landscape with extremely reliable water supplies could receive consistent use by ducks year after year (in essence, almost drought proof). The Water Tracker is set up to automatically track wetland habitat and food availability each year and is making these data available to water and wetland managers. Results from this research are a significant step toward understanding how waterfowl and shorebird habitats can be optimally managed on the landscape to support desired populations of these migratory birds during extreme drought. 

Suggested Citation

Matchett, E.L., Reiter, M., Overton, C.T., Jongsomjit, D., and Casazza, M.L., 2021, Using high resolution satellite and telemetry data to track flooded habitats, their use by waterfowl, and evaluate effects of drought on waterfowl and shorebird bioenergetics in California: U.S. Geological Survey Open-File Report 2020–1102, 59 p.,

ISSN: 2331-1258 (online)

Study Area

Table of Contents

  • Chapter A. Waterfowl and Shorebird Habitats, Drought, and Related Research in California’s Central Valley
  • Chapter B. Objective 1: Identify How Drought Influences Available Wetland Habitat Types and the Duration of Flooding
  • Chapter C. Objective 2: Evaluate the Impact of Changes in Waterfowl and Shorebird Food Energy Supplies
  • Chapter D. Objective 3: Integrate Wetland Classification Heuristic with Automated Water Tracking Data to Inform and Evaluate Water Allocation Decisions
  • Chapter E. Objective 4: Integrate Waterfowl Location and Dynamic Water Data to Evaluate Waterfowl Response to Distribution of Water
  • Appendixes
Publication type Report
Publication Subtype USGS Numbered Series
Title Using high resolution satellite and telemetry data to track flooded habitats, their use by waterfowl, and evaluate effects of drought on waterfowl and shorebird bioenergetics in California
Series title Open-File Report
Series number 2020-1102
DOI 10.3133/ofr20201102
Year Published 2021
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) Western Ecological Research Center
Description Report: xi, 59 p.; Data Release
Country United States
State California
Other Geospatial Central Valley
Online Only (Y/N) Y
Google Analytic Metrics Metrics page
Additional publication details