ECOLOGICAL
GUILDS
Two species-rich groups of vertebrate animals are present
on San Marcos Foothills, seedeaters and birds of prey. They
occupy two distinct niches, that is, each serves a particular
ecological role exploited by each member in a different
way. Such groups are known as guilds. The two guilds are
linked ecologically by their use of grasslands, although
their activities take in other habitats as well. (See Map
6, Ecological Guilds.)
Grassland Seedeaters
Members of the seedeaters guild feed mostly on seeds in
the fall and winter and mostly on insects during the breeding
season in spring and summer. (See Table 2, below.) In fall
and winter, flocks of Western Meadowlarks (sometimes exceeding
100 individuals), Red-winged Blackbirds, Mourning Doves,
and European Starlings feed on insects and seeds among all
the grasslands. Savannah Sparrows, as well as smaller numbers
of Lark Sparrows, Lincoln’s Sparrows, Vesper Sparrows,
and Grasshopper Sparrows are present. In spring and summer,
Grasshopper Sparrows are the star attraction, but Rufous-crowned
Sparrows, Lazuli Buntings, and Lark Sparrows are well-represented
also.
San
Marcos Foothills is the only confirmed breeding locality
for Grasshopper Sparrows along the South Coast of Santa
Barbara County. In the North County, Grasshopper Sparrows
breed in scattered locations from the coast to the foothills
of Figueroa Mountain. We know of no Grasshopper Sparrow
population in the County as dense as that on San Marcos
Foothills—at least one pair for every five to six acres
of grassland in summer 2001. (See Map 7, Grasshopper Sparrow
and Burrowing Owl.)
|
Table
2. Seedeating Assemblage on San Marcos Foothills
|
| Breeding
Season (March to July) |
Non-breeding
Season |
| Black-headed
Grosbeak |
Spotted
Towhee |
| Lazuli
Bunding |
California
Towhee |
| Spotted
Towhee |
Rufous-crowned
Sparrow |
| California
Towhee |
Vesper
Sparrow |
| Rufous-crowned
Sparrow |
Savannah
Sparrow |
| Lark
Sparrow |
Lark
Sparrow |
| Grasshopper
Sparrow |
Black-throated
Sparrow |
| Song
Sparrow |
Grasshopper
Sparrow |
| Mourning
Dove |
Fox
Sparrow |
| |
Song
Sparrow |
| |
Lincoln's
Sparrow |
| |
Chipping
Sparrow (migrant) |
| |
Black-chinned
Sparrow |
| |
Golden-crowned
Sparrow |
| |
White-crowned
Sparrow |
| |
Dark-eyed
Junco |
| |
Western
Meadowlark |
| |
Mourning
Dove |
| |
Red-winged
Blackbird |
Twenty-one
seedeating bird species can be found throughout the
year on SMF.
The grasslands provide
the seeds and the insects for most of these guild members. |
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