Monitoring canaries in coal mines, and other bird populations, can uncover limits in habitat management. Over 14 years, a breeding bird assemblage showed substantial declines at a suburban wetland park in Central California. Of the seventy bird species observed here, twenty-five species were known to breed, and four are classified as riparian focal species for conservation. Species richness (S), species diversity (H?) and species evenness (J?) showed little variability among years, however total individuals of all species territories combined (N) showed statistically significant declines. Breeding bird censuses conducted from 1994 to 1998 and 2004 to 2008 showed substantial declines in eleven out of twenty-five species, those of notable conservation interest include common yellowthroat (Geothlypis trichas), Wilson?s warbler (Wilsonia pusilla), and song sparrow (Melospiza melodia). These changes were not related to any measurable alteration in vegetation on the plot, or precipitation/climate, but may be related to changes in habitat surrounding the site. To our knowledge, this is the first long-term breeding bird census of a riparian habitat along the eastern shoreline of San Francisco Bay, California. Management recommendations to benefit the avifauna include adaptive management during monitoring, and expansion of the park?s riparian habitat by enhancing plants in surrounding area restorations.
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