Vertebrate Species in progress

Tricolored Blackbird (Agelaius tricolor) Surveys

Tricolored blackbird is a state-listed endangered species that has declined dramatically in southern California. Once abundant and widespread in San Diego County, there are few known breeding populations remaining at marshes on Conserved Lands. AECOM biologists surveyed for tricolored blackbirds in spring 2021 at historic and recently documented breeding habitats and at potentially suitable habitats. Surveys were to determine if tricolored blackbirds are present during the breeding season and to estimate population size and breeding status. AECOM biologists used a protocol developed by SDMMP to evaluate habitat quality and threats at each suitable habitat site, even those without tricolored blackbirds. These data , and data from subsequent yearly surveys, will be provided to SDMMP to develop management recommendations for tricolored blackbird. Tricolored blackbirds will be surveyed for annually.
Project Focus

Tricolored blackbird

Emily Perkins

San Diego Association of Governments

San Diego Management and Monitoring Program


Kris Preston

Sarah McCutcheon

Kris Preston

Andrew Fisher; Loren Merrill

Project Protocol
San Diego County 2021 Tricolored Blackbird Surveys: Breeding Surveys & Habitat and Threat Assessment

This survey protocol outlines the methods for conducting TRBL surveys across San Diego County in April and May 2021. A team of two surveyors will collect data using two different software packages-Ful

26.77KB Tricolored Blackbird Habitat and Threat Assessment Protocol.docx

Tricolored blackbird Agelaius tricolor

Goal: Protect, enhance, and restore Tricolored blackbird occupied and historically occupied habitat to create resilient, self-sustaining populations that provide for persistence over the long-term (>100 years).

local NFO 2017, 2018, 2019, 2020, 2021 SL

Management units: 3, 4, 5, 6, 9, 10, 11

Beginning in 2017, annually inspect suitable nesting habitat at current and historically occupied sites (see occurrence table) to determine management needs (including need for additional water) taking care not to disturb nesting tricolored blackbirds, and use a regional IMG monitoring protocol to collect covariate data on human activities and other threats to determine management needs.

Action Statement Action status Projects
IMP-1 Conduct regional IMG monitoring protocol surveys to determine management needs (including need for additonal water) taking care not to disturb nesting tricolored blackbirds, available for implementation Tricolored Blackbird (Agelaius tricolor) Surveys
IMP-2 Based upon threat evaluation, determine if routine management or more intensive management is warranted. available for implementation
IMP-3 Submit monitoring data and management recommendations to MSP web portal available for implementation Tricolored Blackbird (Agelaius tricolor) Surveys
Criteria Deadline year
Annual IMG monitoring of Tricolored Blackbird completed 2021
File name Lead Author Year Type
2021 Tricolored Blackbird (Agelaius tricolor) Surveys Across Western San Diego County Fisher, Andrew 2022 powerpoint presentation
Recording - March 2022 SDMMP Management and Monitoring Coordination Meeting Fisher, Andrew; Merrill, Loren 2022 recording
Summary of 2021 SDMMP TRBL Surveys AECOM 2022 report
Project Files
File name Lead Author Year Type
Tricolored Blackbird GIS not sure
Tricolored Blackbird GIS not sure