California Projects

Saving the Iconic Tricolored Blackbirds of California's Central Valley

Our Goals
To protect and restore Tricolored Blackbird populations by working with private landowners, conservationists, and agencies to create and sustain critical breeding habitats.
What We’re Doing
Restoring Tricolored Blackbird populations by working with landowners and agencies to protect nesting habitat and adjust harvest timelines so chicks can safely fledge.
Tricolored Blackbird in California's Central Valley. Photo: James Scott

In the 19th century, Tricolored Blackbirds were among the most numerous birds in California, with an estimated population of 2 to 3 million. By 2014, their numbers had plummeted to just 145,000.

Although they resemble Red-winged Blackbirds, Tricolored Blackbirds can be identified by their striking crimson red shoulder patch with a bright white bar. They are unique in North America for their large breeding colonies, sometimes numbering up to 50,000 birds.

Habitat loss is the primary driver of their decline. As marshlands and native foraging areas disappeared along the coast and in the Central Valley, Tricolored Blackbirds became increasingly dependent on agricultural fields, primarily grain fields, for nesting. This puts colonies at risk, as farmers often need to harvest crops before chicks have fledged.

Conservation Success 

Recognizing the urgency of this crisis, Audubon California joined forces with researchers, dairy groups, and wildlife agencies to develop solutions. With support from the USDA’s Natural Resources Conservation Service, we’ve worked with landowners to protect colonies, leading to a population increase in the San Joaquin Valley from a breeding population of 75,000 in 2015 to an estimated 209,000 in 2024.

Private Land Stewards Make an Impact
Tricolored Blackbirds at a dairy farm near Planada, California. Photo: Andri Tambunan

Most Tricolored Blackbirds now rely on private, working lands for nesting and foraging. As a result, farms and ranches play a critical role in conserving the species. 

2024 By the Numbers:

  • 16 colonies found and protected on private land.

  • 13 colonies successfully produced young.

  • 3 colonies were impacted by weather, leading to early abandonment.

  • 184,000 birds successfully bred (209,000 birds protected, including failed colonies).

  • Largest colony: ~37,500 adult birds.

  • Average colony size: 14,000 adult birds.

Thriving Tricolored Blackbird colonies indicate environmentally healthy lands, and land stewards can help Tricolored Blackbirds on their land. If you live in an area where Tricolored Blackbirds occur, there are a number of actions you can take to create a good home for them:

  • Make sure there is water nearby.

  • Protect colonies from disturbance.

  • Protect silage colonies.

Land Steward Support Resources are available for landowners who want to protect nesting Tricolored Blackbirds. Programs such as those offered by the NRCS provide financial assistance to offset losses from delayed harvests that protect bird colonies.  Contact your NRCS field office to enroll in assistance programs.

Landowners interested in learning more about nesting season timing, available technical and financial support, and how their land can be part of the solution can contact one of our team members:

  • Ian Souza-Cole - Ian.SouzaCole@audubon.org
  • Xerónimo Castañeda - Xerónimo.Castañeda@audubon.org