128 HISTORY OF THE 



Great Blue, but more strictly a nocturnal bird; seldom found in 

 large flocks, and, though found breeding in rookeries, the mated 

 pair as a rule prefer to nest alone. 



Their nests are placed on the branches of trees and bushes 

 skirting the streams and ponds, and are loosely made of sticks, 

 and lined with twigs in leaf. Eggs four or five; average di- 

 mensions of three sets, two of four and one of five, 1.52x1.10; 

 light greenish blue; in form, oval to elliptical oval. 



GENUS NYCTICORAX STEPHENS. 



"Medium-sized Herons, of very short, thick build, large, thick heads, and 

 short tarsi. The plumage exceeding different in the adult and young, but the 

 sexes similar. Adults with two or three exceedingly long, thread-like, white 

 occipital plumes. 



"Bill very stout, the depth through the base being more than one-fourth the 

 culmen; the latter nearly straight for the basal two-thirds, then gently decurved 

 to the tip; lower edge of the maudibular rauii nearly straight; gouys nearly 

 straight, very slightly ascending; maxillary tomium decidedly concave, with a 

 convex outline just forward of the rictus. Frontal apex reaching more than 

 half way from the center of the eye to the point of the bill and to beyond the 

 anterior end of the nostril; malar apex falling a little short of the frontal apex. 

 Tarsi a little longer than the middle toe, its scutellse hexagonal in front; lateral 

 toes nearly equal, but the outer the longer; hallux less than half the middle toe; 

 bare portion of tibia shorter than the hallux. Inner webs of two outer prima- 

 ries distinctly emarginated near the end. Tail of twelve broad, moderately- 

 hard feathers, as in the typical Herons." 



SUBGENUS NYCTICORAX. 



Culmen about as long as the tarsus; gonys nearly straight, and lateral out- 

 lines of bill slightly concave; tarsus but little longer than middle toe; scapulars 

 broad, blended. (Ridgway.) 



Nycticorax nycticorax naevius (BODD.). 



BLACK-CROWNED NIGHT HERON. 

 PLATE IX. 



Summer resident; not uncommon. Arrive from the first to 

 the middle of April; begin laying about the middle of May; 

 return by the first of November. 



B. 495. R. 495. C. 664. G. 229, 58. U. 202. 



HABITAT. Nearly the whole of America except the Arctic 

 regions. 



SP. CHAK. "Adult: Pileum, scapulars and interscapulars glossy blackish 

 bottle green; forehead, postocular, malar and gular regions and medial lower 

 parts white; lateral lower parts and neck, except in front, pale ash gray, with a 



