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Prothonotary Warbler

Increase Prothonotary Warbler Population at the

Jug Bay Wetlands Sanctuary

ALAN CHRISTIAN 2023 CITIZEN SCIENCE SUMMIT

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Prothonotary Warbler

(AKA - Golden Swamp Warbler)

  • Named for clerics in Catholic Church
  • Only member of genus Protonotaria citrea
  • “tsweet, tsweet, tweet”
  • Breeds in Eastern United States
  • Winter in Mexico, Central and Northern South America in Mangrove swamps
  • Nests in Cavities - May through August
  • 3 to 7 Eggs, 10 to 12 days Incubation, 10 to 12 days later fledge
  • Up to 2 Broods per year
  • Diet consists mostly of insects, snails and some seed and fruit

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Prothonotary Warbler

Population Decline

  • North American Bird Conservation Initiative
    • 2021 Birds of Conservation Concern
    • 1.1 Percent Reduction Annually from 1966 to 2017 resulting in 50 Percent Population reduction over past 50 years
  • Monitoring Avian Productivity and Survivorship (MAPS)
    • 1993 - 2018, 51 Banded for average of 2 per year
    • 4 years, no Prothonotaries banded
    • 2004 - 2016, Average only 1 per year
    • 2017 - 5 Prothonotaries banded
    • 2021 - 2023 15 banded for an average of 5 per year

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Prothonotary Warbler

Nest Box Program

  • 2014 - Initial Effort with 30 PVC Boxes
    • Population Study by Frode Jacobsen
    • Successfully used in Midwest
    • Removed in 2017 - None Utilized
  • 2016 - Wooden Boxes Installed
  • 2017 - Installed Predator Guards on 9 Boxes
    • Installed along Marsh Boardwalk, Railroad Bed, Otter Point and Two Run Trails
  • Unused boxes moved after 2 or 3 years and currently 13 boxes in use

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Prothonotary Warbler

Monitoring Results

  • 2017 - Initial year 27 fledged and 5 banded
  • 7 year average of 4 nests per year
    • With a low of 3 and a high of 6
  • 7 year average of 19 birds fledged per year
    • With a low of 12 and a high of 27

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Prothonotary Warbler

Carolina Wren Nests

  • Carolina Wren nests increased
    • From 1 in 2017 to as many as 7 in 2021
  • Carolina Wrens that fledged increased
    • From 4 birds to as many as 32 in 2021
  • Nest boxes have provided increased opportunity for wrens

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Prothonotary Warbler

PROW vs. CARW Fledged

  • Both utilize same nest site
    • Natural cavity or nest box
  • Both use similar nest material at JBWS (Moss and leaves)
  • Both eggs are similar
  • Both diets are similar with wrens consuming more seed
  • CARW start nesting in March
  • PROW start nesting in May

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Prothonotary Warbler

Analysis and Future

  • Results
    • Boxes have not increased population
  • Possible Reasons
    • Increased competition by Carolina Wrens
    • Changes in habitat - EAB, Ash Trees and more open marsh
  • Future
    • Continue to monitor boxes and adjust locations as the habitat changes