COLAPTES AURATUS, GOLDEN-WINGED WOODPECKER. 293 



(Iowa).— Dall & Bank., Tr. Cliic. Acad. 1869, 275 (Yukou River, Alaska).— 

 Fowler, Am. Nat. iii, 1869, 422 (biography).— Snow, B. Ivans. 1873, 3.— Allen, 

 Bull. M. C. Z. iii, 1872, 180 (East Kansas).— Hakt., Man. Brit. Birds, 1872, 123 

 (England).— CouES., Key, 1872, 197, fig. 132.— B. B. & R., N. A. B. ii, 1874, 575, 

 pj. 55, f. 1. 2; and of most authors. 

 Geopicua duratus, Malii., Mon. Pic. ii, 255, pi. 109, figs. 5, 6, 7. 



The following synonyms refer to specimens intermediate in varying degree between 

 auratus and mexicatius : 



Colaptes ayresH, AuD., B. Am. vii, 1843, 348, pi. 494 (Fort Union, Upper Missouri River; 



mostly auratiifi, but with red moustaches). (Not of Heeum., P. R. R. Rep. x, 



18.59, pt. vi, 59, Califoruia, which is C. chrysoides.) 

 Colaptes lujhridus, Bd., B. N. A. 1858, 122 (excl. syn. Gcopicus clirysoidcs, Malu ; gives 



ail the stages).— Hayd., Rep. 1862, 156.— Stev., U. S. Geol. Surv. Terr. 1870, 



463.— SNcnv, B. Kans. 1873, 3. 

 Pkus aurato-mexicaiuis, Sund., Consp. Av. Pic. 1866, 72. 



Hab.— 'Eastern North America, to the slopes and foot-hills of the Rocky Mountains, 

 where in many localities it becomes mixed with C. mexicainis. Alaska {Dull). Gree|jlaud 

 (Eeiuhardt). Accidental in Europe (Amesbury Park, Wilts, England, one instance; 

 "Marsh, Zool. 1859, p. 6327"; Hart., Brit. Biids, 1872, 123). Breeds throughout its 

 ranire ; resident from the Middle States southward. 



List of specimens from the Warren Expedition. — A, true auratus : 4620, Fort Leaven- 

 worth ; 4619, Upper Missouri ; 5221, Fort Lookout; 8868, tifty miles above mouth of 

 Platte River ; 8866-67, Fremont, Platte River ; 8861-62, 8864-65, Loup Fork.— B, aurato- 

 mexicanus : 5214, Fort Pierre ; 5225, near Fort Pierre ; 5220, 5222-23, Squaw Butte Creek ; 

 5215, Powder River; 5211, 5216, Fort Uniou ; .5224, White Earth River; 5212-13, 5217-19, 

 Yellowstone River: 8863, Loup Fork ; 8869, fifty miles above mouth of Platte. Of the 

 foregoing specimens, not tyi^ical auratus, Nos. .5211-13 have red or orange predomina- 

 ting on the shafts, and are nearer mexicanus than auratus ; the remainder are yellow- 

 shafted, and nearer auratus. 



Laier expeditions.— m-dbl-Q (Wyoming); 60800, North Platte; 61093, Green River (all 

 "lujh-idus"). 



Dr. Hayden's numerous examples are principally those that enabled Prof. Baird to 

 elucidate one of the most remarkable cases in American ornithology — the perfect inter- 

 gradation of two such distinct species as auratus and mexicanus. This author adopted, 

 without qualification, the hypothesis of hybridization, remarking, in proposing the 

 name the hyhridus : " By the above name I intend to cover a remarkable series of 

 Woodpeckers, from the Upper Missouri and Yellowstone, combining the characteristics 

 of Colaptes auratus and mexicanus, in })roportions varying with ahiiost each individual, 

 and leading irresistably to the conclusion that they are the descendants of originals of 

 the species mentioned above, mixed up by interbreeding of successive generations, to 

 a degree unparalleled in the annals of ornithology." He traces the successive steps of 

 departure from the typical ai!r((tus into mexicanus, and forcibly illustrates the grada- 

 tions with a comparative ta1)nlation of the varying characters. The first deviation 

 is the appearance of red feathers in the black maxillary patches;* these increase till 

 they prevail, finally to the exclusion of the black, resulting in the wholly red patch of 

 the mexicanus. With this occurs the diminution and final extinction of the scarlet 

 nuchal crescent, where coiucidently we find the characteristic golden-yellow ou the 

 wing and tail passing through an intermediate orange into the red of mexicanus, a 

 change accompanied with another affecting the i)eculiar lilac-brown of the throat and 

 olive-brown of the back, which become respectively nieiged into ashen and purplish- 

 giay. 



If there ever were a case of hybridization to an unlimited extent, resulting in fertile 

 offspring, that again and again interbred, this would apj)ear to be one ; and it has been 

 so accepted by the majority of ornithologists without hesitation. But we may well 

 pause before committing ourselves to au liypothesis of hybridization ou such au im- 

 mense scale. In tbe light of late researches ui)on the <iuesti()U of climatic variation 

 according to inflexible and inl'allilile laws, most of the lesser instances of supposed 

 hybridity have seemed less weighty. Tlie i)i('sent may be considered a test case — the 

 strongest argument of those wlio maintain hybridity. 



A slight circumstance may give a clue to tlie case, and lead up lo impartial consid- 

 erations. As stated in the " Key" (p. 198), I am informed by Mr. AlUu that Floridaii 

 exanqtles of C. auratus sometimes show red touches in the black nnixillary patches. 



* These black patches are supposed to be entirely wanting in the female. But Mr. 

 W. D. Scott says (Pr. Best. Soc. Oct. 1872): "An iu'imature female (sex noted by care- 

 ful dissection) had a dark cheek-patch, differing only IVoni tbat of the mature male in 

 having giay fcatlieis mixed witli the black. In an adult female the outlines of the 

 cheek-patch can be plainly seen." 



