Analytical Keys 



For the ready identification of birds of California. 

 Foreword 



The following pages present a rough abstract of the structural characters and relationships of the 

 birds of California. Our purpose here being a purely practical one, viz., to establish identity, we have 

 sometimes seized upon the most trifling or superficial characters, provided only that these are conspicu- 

 ous or decisive. No attempt has been made to give a complete account either of structural characters 

 or of systematic divisions; and no mention has been made of several natural but subordinate groupings, 

 such as super-orders, sub-orders, and sub-families. Consideration of even generic distinctions has 

 been sacrificed in the interests of simplicity. 



The irreducible minimum of systematic apparatus would appear to involve the recognition of 

 Orders, Families, and Species. The Keys are, accordingly, based upon these threefold distinctions. 



Of course the accurate use of any key must depend upon a bird or bird-skins at hand. But because 

 many of the readers of this work may not have convenient access to labelled specimens, or may not care 

 to kill birds for temporary needs, we have used as far as possible field characters, or "recognition marks," 

 through which even the most superficial glimpse of a bird ma}' lead hopefully to recognition. 



Lastly, the writer disclaims any assumption of authority in the realm of taxonomy. He has only 

 interpreted, somewhat hastily, the labors of others, and is frankly beholden to such outstanding author- 

 ities as Ridgway and Coues, as well as to Dr. Lynds Jones, who kindly prepared the keys for the author's 

 earlier works, "The Birds of Ohio" and "The Birds of Washington." 



How to use the Keys 



With a bird in hand which we wish to identify, say, a Sora Rail (Porzana Carolina), we inquire, 

 first, what order it belongs to. Turning to page 2069, "Key to the Californian Orders," we read : "I. Feet 

 with webs or lobes." Our bird has simple, or naked, toes, so we pass to "II. Feet with neither webs 

 nor lobes" — which fits our case. Here "A. Legs and neck lengthened" does not apply; but "B. Legs 

 and neck not decidedly lengthened" does apply. Under B. "1. Feet relatively larger; toes long and 

 slender" fits exactly. Our bird belongs to Order No. 14, the Ralliformes. We turn then to the "Key 

 to the Families," beginning on page 2070. Under "Order 14, Ralliformes, Rails, Crakes," etc., page 2073, 

 we read a brief description of the birds of this group and learn that the Order Ralliformes has only one 

 family, the Rallidce. We pass then to the "Key to the Species," beginning on page 2075. Here, also 

 under Order 14, Ralliformes (p. 2089), we find an analysis of the Californian species of the family Rallidm. 

 Our bird falls under "I. Toes simple; body compressed; no frontal shield"; but not under "A. Length 

 about 15 inches." We pass to "B. Length above 8 inches." Our bird, measured along the back from 

 the tip of the bill to the end of the tail measures 8.50 inches; while its bill, measured (preferably by 

 calipers, or "dividers") from the tip to the feathers at the base of the upper mandible (chord of culmen) 

 is only .75 inches - "2. Bill decidedly less than one inch long." Our bird is No. 306, Sora Rail. 



Guided by the figures on the shelf-back of the volumes, we turn to Volume III, or else refer to the 

 Index, and read on page 1540 a detailed description of the Sora Rail, Porzana Carolina, and receive 

 abundant confirmation of our analysis. Here, for the sake of practice, perhaps, we will wish to check 

 up, point by point, upon the color characters, and to measure, preferably by calipers, the distance from 

 the bend of the wing to the tip of the primaries; also the tarsus from the heel joint (the sharp point of 

 the calipers will find a little hollow between the bones of tibia and tarsus) and the angle formed by the 

 outer (4th) toe. The length of the tail may likewise be determined by setting the calipers snugly into 

 the base, or point of insertion, of the central rectrices. These four characters of bill-length, tarsus- 

 length, wing- and tail-length, are notably constant within the species, but due allowance must be made 

 for molting and wear of feathers, as well as for individual variation. 



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