130 BULLETIN 135, UNITED STATES NATIONAL MUSEUM 



Behavior. — Dr. Alexander Wetmore's (1916a) experiments in 

 ascertaining the speed of flight of certain birds, included two observa- 

 tions on this subspecies. The experiments were made in a moving 

 automobile, driven at the same speed as a bird flying paraUel with 

 it, by keeping close watch of the bird and the speedometer. The 

 two herons were about 70 yards away; they were observed sepa- 

 rately' ; and t]\ey both traveled at exactly the same speed, 28 miles 

 an hour. 



DISTRIBUTION 



Range. — "Pacific coast region of the United States, ranging east to 

 San Gabriel, western California and Baird, central northern CaUfornia; 

 south to San Diego, southwestern California; west to Santa Barbara 

 Islands and north to western Oregon. iVpparently a permanent resi- 

 dent throughout most or all of its range but stragglers in winter have 

 been detected west to the Farallon Islands, California and east to St. 

 John, Glenn County, California." (Oberholser 1912a) 



Egg dates. — California and Oregon: 91 records, February 18 to 

 May 27; 46 records, March 30 to April 23. 



ARDEA HERODIAS SANCTILUCAE Thayer and Bangs 

 ESPIRITU SANTO HERON 



HABITS 



The "very light colors" of the great blue heron of southern Lower 

 California were first mentioned by Baird, Brewer, and Ridgway 

 (1884); Brewster (1902a) enlarged upon this point and suggested 

 recognition as a subspecies; but it was 10 years later when Thayer 

 and Bangs (1912) actually named this local race. It is characterized 

 as "a very large great blue heron, with all the colors very pale." 

 In size it is nearly as large as wardi of Florida; and in color it is 

 almost exactly like cognata of the Galapagos Islands. 



Very little has been published regarding its habits, which are prob- 

 ably not essentially different from those of the other subspecies. The 

 coUector of the type series, W. W. Brown, jr., found a large colony 

 breeding on Espiritu Santo Island, and another smaller colony in a 

 mangrove swamp on San Jose Island. "The nests, well-made plat- 

 forms of sticks, about 4 feet in diameter, were placed in the trees at 

 about 40 feet from the ground." Six sets of eggs were collected here 

 between February 15 and 18, 1909, of which the average measure- 

 ments were 52 by 36.5 millimeters; the eggs showing the four extremes 

 measure 59.4 by 42.1, 55.5 by 43.8 and 47.5 by 34.2 miflimeters. 



DISTRIBUTION 



Range. — Known only from southern Lower California (Espiritu 

 Santo Island and San Jose del Cabo) wheye it is probably resident. 



