Predicting the effects of restoration on wetland birds:
South San Francisco Bay Habitat Conservation Model

The South San Francisco Bay salt pond complex comprises one of the most important Pacific Coast sites for waterbirds, hosting millions of wintering and breeding shorebirds, waterfowl and other waterbirds annually.  However, the conversion of most of the South Bay's natural wetlands to salt ponds has also reduced available habitat for a range of tidal marsh-dependent bird species, including the Alameda Song Sparrow and the federally-listed California Clapper Rail, as well as plants and other animals.

South San Francisco Bay: a mosaic of wetland habitats

Now that salt production is less economically viable in the region and a greater premium is placed on the restoration of tidal marsh habitat, over 15,000 acres of commercial salt ponds have been sold to the U.S. Fish and Wildlife Service and the State of California for restoration purposes.  This will result in a significant change in the South Bay's wetland landscape, creating a need to evaluate the interrelated and potentially conflicting habitat needs of a wide range of species, in order to inform landscape-level acquisition priorities and guide site-level project design.

Using a combination of standardized bird survey protocols, aerial photo interpretation, statistical analysis and spatial modeling, PRBO has developed a first generation habitat conversion model, which may be used to estimate the quantitative and qualitative effects of bayland habitat conversion on bird populations.

The size, location, and physical attributes of salt ponds preferred by waterbirds, and the value to birds of natural salt ponds, channels and other features within variable tidal marsh habitat, were not previously well known. We have quantified this variation and used it to predict the loss of waterbird numbers, and gain in landbirds, with the restoration of specific ponds to tidal marsh. We have also evaluated the impacts of several actual proposed restoration alternatives on South Bay bird populations.

Phase II Report (December 2006):

Habitat Conversion Model Phase II, downloadable report (pdf file)

Habitat Conversion Model Phase II, downloadable appendices (pdf file)

Phase I Report (November 2003): 

Habitat Conversion Model Phase I, downloadable report (pdf file)

For more info, contact: Diana Stralberg