38 ALTRICIAL GRALLATUKES — HEEODIONES. 



different species, will feed quietly near one another ; but let another approach, and 

 before it is within a hundred yards it will l)e at once pursued, and the attempt made 

 to drive it away ; and the pursuer and pursued will always be of the same species. 

 But if the approaching bird is of a species different from any of those feeding, it may 

 descend among them without being disturbed. In this petulance to one of its own 

 species a Heron never makes any mistake. Even the small ]31ue Heron, whose young 

 are for a year as white as the White Egret, never mistakes the latter for one of its 

 own kind. It is this habit of attacking only birds of its own species that first led 

 Mr. Moore to regard the rufa and the Pealei as identical ; for the purple chase the 

 white, and the white pursue the purple, but they never tease any other species. 



These birds use their legs and toes to scrape the oozy bottom, or among the 

 plants, in order to uncoA^er their hidden prey. It is a mode peculiar to this species, 

 and not to be mistaken for that of any other ; but both of the two varieties per- 

 form this act in the same manner, and their unity of action in other respects is said 

 to be very conspicuous. No other Heron is so awkward, impetuous, and clumsy a 

 fisher. In clear water it gives chase to its j)rey with exj^anded wings, which are flirted 

 up and down, or are held open, as it runs or hops, sometimes out of the water, some- 

 times turning entirely round. In all these wild and awkward movements the two 

 forms exactly imitate each other. In size, too, they are exactly the same. As chasers 

 the two forms are not only alike, but are superior to all others of the family. They 

 pursue their prey — which is almost exclusively fishes — by hasty steps, hops, and 

 doublings. Instead of being shy and suspicious, as Audubon states, they are, ac- 

 cording to Mr. Moore, almost as unsuspicious as the Green Heron. This bird breeds 

 in company both with its own and with other species, such as egretta, ccoididissima, 

 ludoviciana, virescens, etc. If, Avhen wounded, it falls into the water, it can swim 

 readily. So far as Mr. Moore's experience goes, the proportion in numbers of the 

 white to the blue is as one to eight. 



Two eggs of this species, obtained by ]\Ir. Audubon in 1832 on the Florida Keys, 

 are of a rounded oval shape, are larger than the eggs of the Pealei, and the shell 

 is thicker and rougher. They have the uniform greenish-blue shading common to 

 the eggs of all our true Herons, — a washing of Prussian blue with a slight tinge of 

 green. One (Xo. 98) measures 2.14 inches in length, by 1.G5 inches in breadth. The 

 other (784) measures 2.20 inches by 1.6G. 



Genus HYDRANASSA, Baird. 



< " Dcmiegretta" (nee Blytii), Baiud, B. N. Am. 1858, 660 (part). 



=^ Ilijdranassa, Baiud, B. Ts. Am. 1858, 6C0, in text. Type, Ardca ludoviciana, Wil.s.,=>/. tricolor, 



Jliiller. 

 <Erodiics, Eeicuenow, J. f. 0. 1877, 268 (includes Dicliromanassa, Leptcrodius, Herodius, and 



Garzetta). 



Gen. Char. Small Herons of variegated colors, white beneatli, plumbeous above, the l)ill 

 ec^ual to or longer than the tarsus, and very slender. Bill long and slender, but little compressed ; 

 the upjier and lower outlines appreciably concave about the middle, the gonys almost straight and 

 but sliglitly ascending, the culnien gently convex towards the end. Mental apex reaching less 

 than one third the distance from the middle of the eye to the point of the bill, but, at the same 

 time, al)(3ut as far forward as the anterior end of the nostril ; malar apex reaching about as far for- 

 ward as the frontal feathers. Tarsus long, about e([ual to the bill ; middle toe about two thirds 

 the lengtli of the tarsus, the liallux about half as long as the hitter ; bare portion of the tibia 

 decidedly shorter than the middle toe. Adult, with feathers of the neck, except throat, distinctly 



