HEEONS 259 



The nest was of very loose construction, as are all herons' nests, a mere 

 pile of dead brittle willow twigs from 1 to 5 millimeters in diameter and 

 up to 400 millimeters in len^h. It measured 280 to 300 millimeters in 

 outside diameter and about 180 millimeters in depth. In profile it was 

 triangular, with the apex downward. There was a rounded depression in 

 the top, 70 millimeters deep at the center, from which point it sloped up 

 to the very rim of the nest. This depression held the 5 eggs, which were 

 of the vivid unspotted green color common to eggs of most herons. Four 

 of the eggs weighed 18.1, 19.3, 19.5, and 20.0 grams, respectively. 



As the observer first approached, he could see, from below, the sitting 

 bird; her dully streaked under tail coverts, her slender neck and bill, and 

 her glistening eye showed plainly. When the observer started to climb 

 the tree, she left the nest and, as she took off over the slough, he was able 

 to see the cinnamon brown of her neck. The bird remained in the vicinity 

 and her harsh squawk was heard twice at short intervals, followed in one 

 instance by a series of clucking notes, such as one would give when urging 

 a horse to start. This heron, like herons in general, gave little attention 

 to cleanliness about the nest, and the ground and vegetation beneath the 

 nest tree were spattered with white excrement, a telltale feature marking 

 the location of the nest. 



Black-crowned Night Heron. Nycticorax nycticorax naevius (Boddaert) 



Field characters. — Considerably smaller than Great Blue Heron, and with noticeably 

 shorter legs and neck. Prevailing coloration of body and wings light gray; under 

 surface whitish; top of head and back greenish black. (There are usually two or three 

 long slender plumes, % inch wide, extending backward from crown of head to middle 

 of back.) Young birds are streaked all over with light and dark brown. Flight slow, 

 direct, with deliberate wing beats. Voice: A sharp harsh squawk. 



Occurrence. — Thinly scattered as a resident west of foothills. Frequents vicinity of 

 water and roosts and nests in trees near by. Seen at Snelling May 26, 1915, and near 

 Lagrange, December 14, 1915, and May 8, 1919. 



Black-crowned Night Herons are resident in small numbers along the 

 Merced and Tuolumne rivers below their exit from the foothills. The 

 harsh-voiced notes of the birds, of frequent utterance during the night 

 when they are active, have given them the common name of "squawk." 

 Like most other herons they get their food from the margins of ponds 

 and sluggish streams. The birds roost throughout the day in concealment, 

 congregated in dense willow thickets, whence they issue forth at dusk to 

 forage singly over the surrounding bottomlands. 



