Riparian Habitat Joint Venture

By Lyann Comrack, Riparian Habitat Joint Venture Coordinator

California Partners in Flight (CPIF) launched the ambitious Riparian Habitat Joint Venture (RHJV) project in September, 1994. The RHJV, modeled after the successful joint venture projects of the North American waterfowl plan, reinforces other collaborative efforts currently underway which protect biodiversity and enhance natural resources as well as the human element they support. To date, eighteen federal, state and private organizations have signed the landmark cooperative agreement to protect and enhance habitats for native landbirds throughout California.

Riparian habitats were selected as the CPIF’s first habitat joint venture as they have the highest diversity and productivity of landbirds of any terrestrial habitat type in the western United States. Deciduous riparian forests, comprised mostly of willow, alder, cottonwood and dense undergrowth bordering streams and lakes, have largely been lost to stream channelization, development, logging, grazing, and water diversion throughout the west. Only five to ten percent of California’s original riparian habitat exists today and the remaining portions continue to be developed or destroyed.

By developing a coordinated statewide effort, increasingly fragmented habitat patches will be connected and enlarged with an extensive network of riparian forests capable of supporting viable breeding populations of native birds. A wide variety of other species of plants and animals will benefit through the protection of forests along our rivers, streams and lakes. Further, RHJV results and recommendations will be fully integrated into other multi-species planning efforts through participation of member organizations.

Fourteen bird species were purposely selected for this treatment which include indicators of a broad range of riparian habitat conditions. They are: Swainson’s Hawk, Yellow-billed Cuckoo, Willow Flycatcher, Bank Swallow, Swainson’s Thrush, Bell’s Vireo, Yellow Warbler, Wilson’s Warbler, Common Yellowthroat, Yellow-breasted Chat, Blue Grosbeak, Song Sparrow, and Black-headed Grosbeak.

Detailed information on historical and current distribution and abundance, optimal habitat characteristics and preferences, average territory size and minimum patch size required for successful breeding, best management practices, special factors, and scientific references has been collected for each species. The initial goal of this effort is the development of general reference materials for comparative purposes that will be improved upon over time. Results of our work to date including species accounts, current and historical range maps as well as species richness maps are available for viewing through the Point Reyes Bird Observatory website at http://www.prbo.org/prbo.