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i88 Bird -Lore DECEMBER AND JANUARY BIRD-LIFE ON EASTERN SIDE OF SAN FRANCISCO BAY Bv Chari-ks Keeler To describe the bird life of California within the limits of the present series of sketches would be an impossible task. This great state, stretching in a broad band along the Pacific coast, diversified as it is b}' two long mountain ranges extending in a general northerly and southerly trend, embracing a wide interior valley and cutting off the district to the east, which is left an arid waste, contains a greater number of faunal zones than any other region of corresponding size on the American continent. In the valleys the rigors of an eastern winter are unknown ; in the mountains the snow-drifts are as deep as in Canada. Even in so restricted a section as the San Francisco Bay region there is considerable diversity in fauna and iiora. Upon the western side of the bay, and more particularly on the north- western shore, the redwood forests determine to a large extent the distribution of both plants and birds, while on the eastern shore the redwoods are confined to one or two restricted pockets in the hills. It is to the birds of this eastern side that I shall confine my obser- vations. The hills here rise to a height of a thousand feet or more, with a gently descending plain at their base, reaching down to the bay shore two or three miles away. These hills are treeless save where forests of eucalyptus have been planted and are covered with grass and chaparral. In the little caiions which cut through the range at frequent intervals are groves of superb live-oak trees in the lower reaches and laurel, scrub oak and alders higher up. In the severest winter weather the thermometer seldom falls as low as 25°, and frosty mornings are the exception. Rain falls at more or less frequent intervals during this season, but showers are almost unknown during the summer months. As a consequence of the mildness of the winters, birds are quite as abundant at this time of year as at any other, and the list of permanent residents is comparatively large. Some among these, such as the California Brown Towhee, Spurred Towhee, the Green-backed or Arkansas Goldfinch, Plain-crested Titmouse, Wren-Tit, California Bush-Tit, California Jay, Anna's Hummingbird, Western Meadow- lark, Samuel's Song Sparrow, and the Red-shafted Flicker, are, so far as I can detect, permanent residents. By this I mean that there seems to be no evidence that the individuals which nest here go away for the winter to be replaced by others of the same species. Of course this is a difficult point to prove, but there is every indica- tion of stability with these species. They are found in about the same places all the year round, and at no one season do they seem more abundant than at another. To have learned to distinguish them