Vertebrate Species in progress

Northern Harrier (Circus cyaneus) Surveys

Northern harrier is a species that has disappeared as a breeding resident from many areas in southern California. Once abundant and widespread in San Diego County, there are few known breeding populations remaining in marshes and grasslands on Conserved Lands. In 2021, AECOM surveyed for northern harriers at historic and recently documented breeding sites and in other suitable habitat to determine if harriers are present during the breeding season, and to estimate population size and breeding status. AECOM used an SDMMP protocol to evaluate habitat quality and threats at each suitable habitat site, even those without northern harriers. SDMMP will use these data, and data from subsequent surveys, for the development of management priorities.
Project Focus

Northern harrier

Emily Perkins

San Diego Association of Governments

San Diego Management and Monitoring Program


Loren Merrill

Sarah McCutcheon

Kris Preston

Andrew Fisher; Loren Merrill

Project Protocol
San Diego County 2021 Northern Harrier Surveys: Breeding Surveys and Habitat and Threat Assessments

This survey protocol outlines the methods for conducting NOHA surveys across San Diego County between April and July, 2021.

25.41KB Northern Harrier Habitat and Threat Assessment Protocol.docx
File name Lead Author Year Type
2021 Northern Harrier (Circus hudsonius) Surveys Across Western San Diego County Merrill, Loren 2022 powerpoint presentation
Recording - March 2022 SDMMP Management and Monitoring Coordination Meeting Fisher, Andrew; Merrill, Loren 2022 recording
Summary of 2021 SDMMP NOHA Surveys AECOM 2022 report
Project Files