NORTH AMERICAN MARSH BIRDS 129 



The colony consisted of 49 nests and covered an area of about 200 feet by 100 

 feet. The nests were built always upon the very edge of the little sloughs of 3 

 or 4 feet depth, and were sometimes within 5 feet of each other and as far as 20 

 feet apart; but usually about 10 feet was spaced between nests. All nests were 

 constructed of the dried branches of the common marsh grass, and were quite 

 serviceable structures. They varied in size from 2 feet in diameter flat on the 

 ground to 4 feet across and 14 inches in height. Nearly all nests were built 

 upon an old one, and probably in a few years quite high monuments will be 

 erected. The contents of the nests varied from fresh empty nests to those con- 

 taining young about big enough to find their way home again. Sets of eggs were 

 two, three and four and both fresh and incubated eggs were plentiful. 



John G. Tyler (1913) found a colony of nino pairs occupying a 

 large lone cottonwood that stood on the bank of Fish Slough near 

 New Hope in Fresno County. "All these nests were large, well- 

 hollowed platforms strongly built of sticks and placed from 40 to 60 

 feet above the ground." A. B. Howell (1917) says that the herons 

 that breed on the Santa Barbara Islands "build their nests in the 

 niches of the cliffs." J. Eugene Law writes to me that he "found a 

 colony of some size nesting in the tops of the giant native oaks in 

 the vicinity of Visalia on the floor of the San Joaquin Valley of 

 California. Some trees had 15 or 20 nests." 



Eggs. — The eggs are similar to tliose of the eastern subspecies. 

 The measurements of 40 eggs average 61.3 by 43.4 millimeters; the 

 eggs showing the four extremes measure 71.5 by 47.5, 69.5 by 50.5, 

 and 51.3 by 34.8 millimeters. 



Food. — The food of the California heron is, in the main, similar to 

 that of the other subspecies. Mr. Tyler (1913) says: 



The farmers of this county should do all in their power to afford protection 

 to the blue heron, as it is one of the best gopher destroyers in existence. It is 

 no uncommon sight to see a heron standing motionless for hours at a time in 

 an alfalfa field waiting for a gopher to make its appearance. Small fish, frogs, 

 and probably Uzards, if thej^ are obtainable, are eaten, and on many occasions 

 herons have been observed in pairs on the dry barren hillsides along the San 

 Joaquin River busily engaged in catching grasshoppers. AbiHty to adapt itself 

 to changing conditions and a varied diet has caused this bird to become widely 

 diffused throughout the valley, and has, no doubt, assisted materially in 

 preserving the species. 



Mr. W. Leon Dawson (1923) writes: 



We dwellers by the southern sea oftenest descry this bird as a lone watcher far 

 out in the kelp beds, and we are moved to call him the kelp heron. The same 

 tactics of tireless patience and lightning speed evidently avail here to secure for 

 him an abundant harvest of smelts and shrimps, for the bird will stand by the 

 hour on a sinking raft of kelp fronds, though it leave him submerged to the belly. 

 His sea legs are, therefore, considering their great length, rather best on earth, 

 for their owner has to maintain his balance in the face of unceasing motion, and 

 so nicely, that suspicious little fishes shall not be put to flight by a single false 

 motion. 



