NOETH AMERICAN MARSH BIRDS 161 



could see also the black sleek forms of the grackles as they slipped silently from 

 nest to nest, making the most of the absence of incubating egrets and herons to 

 ply their nefarious trade of egg eating. Frequently, too, one of these large black- 

 birds would come to the top of some conspicuous perch and there, with much 

 ado, inflate and deflate himself, producing thereby not only a grotesque appear- 

 ance but also a most peculiar song. From a nearby shrub a gray-tailed card- 

 inal burst into a song of great richness, as if to ridicule the pathetic attempt of 

 the grackle at vocal gymnastics. Everywhere there was life, and everywhere 

 there was beauty and grace and a symphony of sound and color. 



J. R. Pemberton (1922), who visited the island with Captain Camp, 

 estimated that the heron popuhition of the island consisted of about 

 4,000 reddish egrets, 2,000 Louisiana herons, 100 black-crowned night 

 herons and 50 Ward herons. Captain Camp told me that in 1923 

 the total population had increased at least 20 per cent over the pre- 

 vious year. Mr. Pemberton (1922) said that "every individual bush 

 appeared to have nests on it or in it," but that " nearly all the nests" 

 of the reddish egrets "were on the top of the bisbirinda or the Span- 

 ish dagger. The mesquites had very few, although some of the 

 stunted and more robust carried nests." In watching the egrets 

 building their nests, he noticed that "the greater part of the mate- 

 rial consisted of dry salt grass stems, which was placed as lining in 

 old nests, but once in a while a bird carried a dead thorny twig found 

 beneath a mesquite." Captain Camp told me that during the season 

 of 1923 there had been a great increase in the number of nests built 

 on the ground, where a more elaborate type of nest is built of dry 

 grass, with a deeper cavity than in the tree nests. Perhaps the island 

 is becoming overcrowded and building material is harder to find. 

 Evidently the colony is flourishing under the able guardianship of 

 Captain Camp and his assistant who lives on the island. 



There are four sets of eggs of this species in the California Acad- 

 emy of Sciences collected on May 2, 1921, on islands in the Gulf of 

 California. Three of the nests were on the ground under Salicornia 

 bushes and one was on the lower branches of one of these bushes 16 

 inches above the ground. The nests were quite bulky and were well 

 made of dry sticks and twigs of this plant; they measured from 20 

 to 26 inches in diameter outside, from 10 to 12 inches inside, from 8 

 to 10 inches in height and were hollowed to a depth of 3 or 4 inches. 



Eggs. — The reddish egret usually lays from three to four eggs, occa- 

 sionally five and very rarely six or even seven. The shape varies 

 from ovate or oval to elliptical ovate or elliptical oval. The shell is 

 smooth and not glossy. The color is pale bluish green, varjdng from 

 "deep lichen green" to "pale Niagara green" or "pale olivine." 



The measurements of 42 eggs average 51 by 37.6 millimeters; the 

 eggs showing the four extremes measure 65.6 by 38.2, 53.5 by 41.7, 

 46.5 by 36 millimeters. 



