2022 Rangewide Survey for SMHM

During the summer of 2022, over 60 biologists including agency, university and private experts throughout the San Francisco Estuary collaborated to undertake the first single-season, unified regionwide survey of the Salt Marsh Harvest Mouse (SMHM) in over 50 years. 


In July and August, SMHM were surveyed via live-trapping at 55 site and via passive fecal DNA at 30 additional sites throughout the Estuary. The survey targeted both areas where historic trapping had occurred, and areas where little is known about the SMHM population. Genetic samples were collected to assess population variation and mouse presence, while mark-recapture data will yield important demographic information.

Why it Matters

As an endangered species, the protection of the SMHM is a priority for wetland managers throughout the San Francisco Estuary. The results of this survey will proactively guide a resilient response to rapidly changing SMHM habitat, and promote effective conservation of this endangered species for years to come. Furthermore, this survey will provide information supporting several goals within the Tidal Marsh Recovery Plan.