THE CONDOR I Vol. IV and rather scarce in summer. The number of sunny days each year is remark- ably high. The quail, flicker, hairy woodpecker, Steller jay, white-crowned spar row, creeper, and chickadee of the Sierra are either paler, or have more white in their plumage than their representatives in the coast belt. We might, for illus- tration, imagine a desert beset in sumtner with heavy fogs, b?t having ? scarcely any rain. Such a region would probably produce rather dark races of birds. On the other hand a fogless region of comparatively heavy rainfall of peculiar distri- bution, such as the Sierras, produces light races. It is reasonable to suppose-- and tho we take it readily for granted it is not proved entirely--that the dark colors of the northwest coast birds have been assumed in response to protective natural selection. In other words a dark bird, or one with little white in its . plumage is less conspicuous during the critical nesting. period under sombre skies, or in a gloomy forest than a lighter bird, or a bird with considerable white in its plmnage. Conversely, in the brilliant sunlight of the Sierra Nevada a lighter phase of this same species is less conspicuous than a dark form would be. The point to be emphasized of course is that moisture on the whole is only indirectly responsible for the dark races--and is indirectly responsible by its peculiar dis- tribution in the form of fog and clouds thruout the summer. In the following notes it is my object to record a few observations on the life Zones and land birds* of the little-worked redwood belt, from Humboldt Bay to Crescent City, California. I landed at Eureka May 2o, I899 and spent a week in the vicinity of Arcata, at the end of Humboldt Bay. This is in the more open long ago lumbered district close to the coast. From June 8 to 2t I staid at a lum- ber camp north of Mad River close to a large tract of dense primeval forest. Then after spending a few days on the outer peninsula of Humboldt Bay I travelled up the coast by stage, stopping at Trinidad Head, the vicinity of which is lumbered off. One evening was spent at the mouth of the Klamath, and June 29 to July 8 at Crescent City, in the extreme northwest corner of the state. The redwoods occupy a narrow belt next to the coast from the southwestern corner of Oregon (Chetco R.) to about twelve miles south of Punta Gorda, Monte- rey County. North of San Francisco Bay the belt is almost unbroken and as- sumes its greatest width in the country between Cape Mendocino and Humboldt Bay. From Humboldt Bay north the strip scarcely ever exceeds fifteen miles in width. The redwoods typically occupy the low hills and valleys next to the coast, and in the northern portion of their range probably never go over a thous- and feet. In the vicinity of Humboldt Bay the belt ends abruptly at the first ' low range of mountains back of the coast. It is a hazardous undertaking to define precisely the life zone of this strip, from Cape Mendocino'north, for the simple reason that the belt is mixed zonally. There seems little doubt that south of Cape Mendocino the redwood belt is refer- able to the Humid Transition. Considerable confusion exists however as to the proper position of the coast belt north. Dr. Merria?n, in 'Life Zones and Crop Zones,' places it as a division of his Canadian, but without remark. Other
authors in an indefinite way have called the whole coast region boreal without
differentiating the redwood belt from the quite different mountainous district just to the east of it. A little detail seems necessary in dealing with the subject. But in a general way the open country immediately bordering the coast, the river valleys such as those of the Eel and Mad, and old deforested tracts, mostly near the coast and in or near the valley of the principal streams, contain species of birds and plants which would easily relegate these areas to the Humid Trans- ition. The same is true of the mountains immediately to the east of the redwood
- To be published as part II, Co?x-Doll IV, No. ' ?. : ?
