San Joaquin River National Wildlife Refuge

San Joaquin River NWR Songbird Monitoring

Project Summary

PRBO Conservation Science and the San Joaquin River National Wildlife Refuge, located just west of Modesto and now open to the public, initiated a project in 2000 to monitor songbird use of refuge lands along the San Joaquin River between the Stanislaus and Tuolumne River tributaries. A large-scale riparian restoration project planned by the Refuge and developed by Sacramento River Partners involving 3,300 acres of former agricultural lands within the San Joaquin River floodplain began in 2002.

 

 

Our primary objective is to establish a long-term songbird monitoring program to assess bird population responses to the riparian habitat expansion and to monitor songbird re-colonization and use of restored areas. Pre-restoration data on songbird abundance, distribution and reproductive success has been collected in existing riparian habitat and in the fallow agricultural fields slated for restoration. Preliminary results from our first years of data indicate that the Refuge is an important area for songbirds. Ten of the fourteen birds identified by the California Partners in Flight as "Riparian Focal Species" were present on the refuge as breeders (Black-headed Grosbeak, Blue Grosbeak, Common Yellowthroat, Song Sparrow, Swainson's Hawk, Yellow Warbler) or migrants (Swainson's Thrush, Warbling Vireo, Willow Flycatcher, Wilson's Warbler).

Objectives:

  • Collect baseline data on songbird species on Refuge lands prior to the commencement of restoration activities. Restoration began in 2002 on portions of the 1,300 acres of floodplain lands slated for restoration adjacent to the San Joaquin River.
  • Assess importance of existing and planned riparian areas to songbirds by determining abundance, species richness and diversity. Planned riparian areas are currently fallow agricultural fields located within the floodplain of the San Joaquin River.
  • Monitor songbird re-colonization and use of newly restored sites, both naturally restoring and cultivated (planted) sites.
  • Compare songbird use of different riparian habitat types including: a) early- and late-successional riparian, b) early-successional process-based riparian (levee breached by river), and c) cultivated restoration.
  • Contribute to restoration design, implementation and management with knowledge gained from this and other studies on the habitat requirements of birds in riparian areas.
  • Increase and enhance riparian bird habitat through management recommendations that stress the need to maintain a structurally diverse (in age, plant species and height class) native plant community.

We use standardized methods of data collection (e.g., point counts, mist netting and nest monitoring) to achieve our objectives.

Collaborators for this project include the San Luis National Wildlife Refuge Complex of the USFWS, Sacramento River Partners and the Friends of the Tuolumne.

For more information, contact Jeanne Hammond or Julian Wood.