Military History Building Closed until March 10, 2014
The Military History Building is undergoing a Seismic Retrofit (Earthquake Safety) and will be closed through 3/10/14. We apologize for this inconvenience.
Interior of Lighthouse Will Be Closed for Seismic Retrofit
The Lighthouse is undergoing a Seismic retrofit (earthquake safety). It is still open to the public, while the basement is worked on. The interior of the lighthouse will be closed once the basement is completed. Please call (619) 557-5450 for info.
Hidden In Plain View, Our Chaparral Birds
Contributed by Cabrillo National Monument Volunteer Claude Edwards
Birds that are closely tied to chaparral can be subtle and overlooked, literally hiding in plain view. They come in a variety of shapes and sizes, exhibiting different methods for exploiting the vegetation for their benefit. They reveal themselves to those who are sensitive to the subtleness of their surroundings, to the shades of green and brown comprising this environment.
Nearly ten species of birds occurring on Point Loma prefer the chaparral. Most of these are year-round residents and are among the more regularly encountered species on the monthly bird walks at Cabrillo National Monument. One unifying quality about chaparral birds is their generally somber coloration. Most wear shades of brown. Some are patterned with combinations of black, gray, rust, tan, or white. In context with their environments, these qualities help them blend into their surroundings. Notwithstanding their dull and similar-looking plumages, they can be more easily differentiated by the size and shape of their bills, the length and shape of their tails, and by their behaviors.
The most conspicuous bird of the chaparral is the bold and familiar western scrub-jay (Aphelocoma californica). They are unique among their neighbors by their blue coloration patterned with brown and gray. They are large and raucous, relatively smart and tame, and are quick to adapt to human-enhanced conditions. Jays utilize the fruits produced by scrub-oaks, which they often hide, and most are forgotten, effectively planting them.
Two other chaparral birds that are almost as conspicuous but are better known for their distinctive voices are California quail and Bewick’s wren. Both are clothed in brown, but this is where the similarities end. California quails (Callipepla californica) are dimorphic, among those species where males and females appear differently. Male and female quails wear teardrop-shaped plumes, but the male has a boldly patterned face. Although shy by nature, males sit atop shrubs and give a well-known song, “ca-BREE-oh,” repeated three to four times.
Male and female Bewick’s wrens (Thryomanes bewickii) look alike, distinctive with a long white eyebrow stripe and a long and straight bill, good for plucking small insects from stems and leaves. It is an active little bird that easily flits through dense vegetation, often with its tail held upward. The male’s loud song seems out of proportion to its small size, an energetic combination of buzzes and trills that rise and fall during its delivery.
Spotted towhees (Pipilo maculatus) are a handsome bird dressed in a boldly patterned plumage of black and chestnut and white. The sexes are similar-looking and both have striking red eyes. They are most often encountered on the ground, feeding by kicking up leaf litter with their feet. Their loud song varies from one male to another, but is basically a harsh buzz or rattle. However, the usual call note given by both sexes sounds vaguely like a husky-voiced cat!
There are three similarly colored birds frequenting chaparral habitat, the wrentit (Chamaea fasciata), California thrasher (Toxostoma redivivum), and California towhee (Pipilo crissalis). All three wear the same basic shade of dull grayish-brown, but otherwise they can be easily distinguished when heard or seen well. In terms of tameness, the towhee is the most outgoing and likely to be seen without much effort. At Cabrillo National Monument, they frequently appear on sidewalks and flower beds. In size, the wrentit is the smallest and the thrasher is the largest. The wrentit is most closely tied to the vegetation while the towhee is the most terrestrial. The song of the thrasher is the most varied and melodious of the three, and the thrasher’s bill is the most distinctive of all its neighbors, being long, thin, and decurved. It is used for “thrashing” through the leaf litter. They also walk or run, rather that hop or shuffle, like the towhee.
At the other end of the color spectrum, the diminutive orange-crowned warbler (Vermivora celata) is a drab, dull, olive-green, somewhat paler and yellower below. Of all the many species of warblers that have been recorded on Point Loma, this is the only one that nests in our area, the subspecies sordida’. The male and female look alike, but on a rare occasion one may be able to see the male’s dull pumpkin-orange crown patch. Their bill is very thin, as with most insectivores. Two migratory forms are barely distinguishable from the resident birds.
Three final species that are commonly associated with chaparral on Point Loma are hermit thrush (Catharus guttatus), fox sparrow (Passerella iliaca), and golden-crowned sparrow (Zonotrichia atricapilla). These three are winter visitors and are basically similar in size. On the other hand, they vary from one another in shyness and behavior, shades of brown coloration, amount, type and extent of field marks, and vocalizations. More about these at another time.
Did You Know?
Did you know that the coastal sage scrub habitat found at Cabrillo National Monument is one of the most endangered ecosystems in the world? Only 10-15% of the original habitat now exists. Once the dominant ecosystem, the coastal sage scrub community now only exists in small remnant pockets.