AUDEIDJi THE HERONS. 120* 



e*. Smaller, with legs and feet black or dusky, only the tibiae yellowish; total length 

 about 40 to 48 inches; wing, 18.00-19.50; exposed culmen, 5.45-5.95; tarsus, 6.75- 

 7.85. Bab. Whole of temperate North America and parts of tropical Amer- 

 ica A.herodias. 



The relationship between these four species or races is very 

 puzzling, and no one, apparently, fully understands the case- 

 While each of the four forms is easily recognized by the char- 

 acter given above, and while a large majority of specimens are 

 typically either one or the other of them, intermediate examples 

 not unfrequently occur. The only apparent difference between 

 A. herodias and A. wardi consists in general dimensions and in 

 the color of the legs; but in both respects there seems to be a 

 complete intergradation among Florida specimens. On the 

 other hand, A. wardi, A. wuerdemannii, and A. occidentaUs agree 

 minutely in measurements and in the color of the legs; and the 

 first two unquestionably intergrade. The writer has already 

 expressed the hypothesis that A. wuerdemannii and A. occidentals 

 are merely dichromatic phases of one species, corresponding to 

 the colored and white phases of the Reddish Egret (A. rufescens 

 and A. "pealei"). This hypothesis he would now modify by sug- 

 gesting that A. wardi is the perfect colored phase of A. occi- 

 dentalis, and that A. wuerdemannii is merely an intermediate 

 phase, a suggestion prompted by the circumstance that A. 

 wuerdemannii varies more in coloration than either of the others, 

 the variations moreover tending toward both A. wardi and A. 

 occidental-is. Whether the intergradation between A. wardi and 

 A. herodias is the result of hybridization or an evidence of their 

 specific identity remains to be determined, if it be possible to 

 determine it. The whole question is indeed so complicated that 

 much patient research will be necessary before we can hope to 

 know more about it. 



Ardea wuerdemannii Baird. 



Of '' 



WUl'KDEH ANN'S HEKON, 



Ardea wnrdemannii BAIBD, B. N. Am. 1858, 669, ed. I860, atl. pi. 86; Cat. N. Am. B. 1859. 

 No. 488. COUES, Key, 1872, 267; Check List. 1873, No. 460. N ELS. Bull. Essex Inst. 

 Deo, 1876, 151. 



Ardea wuerdemannii A. O. U. Check List, 1886. 351 ( "Hypothetical List." No. 9). BIDGW . 

 Man. N. Am. B. 1887, 128. 583; Proo. U. S. Nat. Mus. x. 1887. 112-115 (critical). -Scorr. 

 Auk. Jan. 1889, 16-17 (description, etc.). 



