The White-tailed Kite 



obsoletus, are reckoned separate species, simply because of isolation, or because of the 

 extirpation of intermediate links. 



The rise and spread of world ornithology is pressing this inconsistency home and 

 is leading to revolt. We are awakening to a knowledge of the fact that widely sepa- 

 rated forms, forms which we had comfortably regarded as distinct species, are in reality 

 very similar. Apart from the fact of geographical separation, their quantitative 

 difference is as slight as that often found in contiguous subspecies. The inference, 

 then, is plain. We have been allowing our rigid and artificial canons of nomenclature 

 to blind us to important facts of relationship. We have strained out taxonomic gnats 

 and swallowed phylogenetic camels. There is now manifest a frank revulsion against 

 this sort of thing, and a tendency to assign purely quantitative values to the concepts 

 of species and subspecies. 



The case of Elanits leucurus (Vieillot) and Elanus axillaris (Latham) is a perfect 

 case in point. The form leucurus, as originally characterized, is confined to the Ameri- 

 cas; the form axillaris (described before leucurus and so taking precedence over it) 

 is confined to the Continent of Australia. Earth's widest ocean rolls between them. 

 And yet a candid comparison of the two forms shows a very slight quantitative difference. 

 If they had been found occupying, say, East and West Australia, respectively, they 

 would be described as «<&-species, and their intergradation would be assumed. The 

 name Elanus axillaris leucurus (for the South American bird) violates the letter of the 

 older canon, but it recognizes a vital fact of relationship, an unquestionable fact of 

 close phylogenetic relationship, which is all the more impressive because of a wide 

 geographical separation between the two forms. 



It is easy to predict that more or less exact quantitative values will eventually be 

 assigned to the concepts of species and subspecies; and the necessity of recognizing 

 mergent forms or form-groups will be met some other way. 



Nesting. — Nest: A bulky mass of sticks and twigs more or less deeply cupped, 

 and lined or not with grasses; placed near top of tree, preferably live oak, and well 

 concealed. Eggs: 3 to 5, usually 4; white or buffy white, heavily blotched and cloud- 

 ed, often completely overlaid with chestnut-brown or rich dark rufous (carob brown). 

 Av. size 42 x 33.5 (1.65 x 1.32). Season: March 15-April; one brood. 



Range of Elanus axillaris. North and South America and Australia. — In North 

 America chiefly confined to California, Texas, Oklahoma, South Carolina, and Florida; 

 casual in the other Gulf States and north to Illinois. Winters in Florida and California 

 and casually (?) south to Guatemala. 



Range of E. a. majusculus (Wholly confined to California). — Resident, rare; 

 formerly common. Found in Upper Sonoran and coastal valleys west of the Sierras 

 from Sonoma County and Red Bluff (Tehama County) south to San Diego. 



Authorities. — Gambel, Proc. Acad. Nat. Sci. Phila., vol. iii., 1846, p. 44 (near 

 Monterey); Fisher, Hawks and Owls of the U. S., 1893, P- 2 3 (food) ; Barlow, Auk, vol. 

 xiv., 1897, p. 14 (Santa Clara Co.; habits, nest and eggs, etc.); Coues, Auk, vol. xiv., 

 1897, p. 216 (nomencl.) ; Bangs and Penard, Proc. New Engl. Zool. Club, vol. vii., 

 1920, p. 47 (syst. ; desc. of Elanus leucurus majusculus, type locality, San Rafael, Calif.). 



RECENT ornithological literature bristles with records of occur- 

 rences of the White-tailed Kite, once upon the verge of extinction, but, 

 now, it is believed, being slowly nursed back into life. The cause of the 

 near tragedy, now hopefully averted, was expressed several years ago by 



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