The avifauna of the MBNMS clearly reflect the physiography of this highly productive region. Three habitats most strongly influence bird occurrence: deep canyons, particularly the Monterey and Ascension canyons; shallow, sand-bottomed continental shelves; and sand beaches, penetrated by estuarine systems, including Elkhorn Slough, Pescadero Marsh, and the Salinas River mouth (Figure 1).
The waters of the MBNMS are among the most heavily utilized by seabirds world-wide. Ninety-four species of seabirds are known to occur regularly within and in the vicinity of MBNMS; among these about 30 are dominant (Briggs et al. 1987; Table 1). About 90 species of tidal and wetland birds occur on the shores, marshes and estuaries bordering on Sanctuary waters; about 30 of these, too, are dominant (Shuford et al. 1989, Ramer et al. 1991; Table 1).
Water depth and distance to the shelf-break front are the factors most critical to determining habitat use of these species (Briggs et al. 1987, Shuford et al. 1989, Allen 1994). Avifaunal species composition overlaps little between the tidal/wetlands and ocean habitats, except for some species of grebes, loons and ducks.
Next - Section II. Seabirds
Seabirds & Shorebirds Table of Contents