NORTH AMERICAN MARSH BIRDS 187 



tops of tall pine saplings. Probably the most populous colony in the county 

 is near Lazaretto station on Tybee Island. Here the birds breed in a jungle 

 of oaks difficult to penetrate. So numerous are they that every available nesting 

 site is occupied, many new nests being built on the foundation of old ones. 



In Massachusetts, I have generally found single nests, but on sev- 

 eral occasions, small colonies. One at Magnolia, many years ago 

 between the beach and a fresh water marsh, consisted of 20 or 30 

 pairs nesting in pitch pines about 20 feet from the ground. Another 

 colony was on an island in the salt marsh at Ipswich in trees of gray 

 birch, red oak, and hickory about 15 feet from the ground. A colony 

 of about 20 nests at Westport on a salt marsh island was in cedars, 

 sassafras, and hickories. In this case the nests varied from 3 to 20 

 feet from the ground. 



The nest itself is a simple affair from 10 to 12 inches in diameter, 

 ill-adapted, it would seem, to hold eggs when the tree branches wave 

 in the wind, for it is a flat platform of sticks, destitute of any sort of 

 lining and not cup shaped. Some at least of the twigs composing 

 the nest are green. The nest is so thin and flimsy that one can some- 

 times look through it from below and see the eggs. In making the 

 nest the herons must weave the twigs in and out to a certain extent, 

 for if they merely laid the sticks one on top of the other, the nest would 

 fall to pieces at the least disturbance. The nests on the ground made of 

 course weeds, reeds, and cat-tails already mentioned are very unusual 

 both in site and material. 



The green heron does not nest with other species as a rule, but is 

 occasionally found nesting in the same grove with little blue, Louisi- 

 ana, black-crowned, and other herons. The boat-tailed grackle and 

 the bronze grackle have also been found nesting in the same group of 

 trees. Mrs. Wheelock (1906) says of the association with the latter 

 birds: 



The grackles were quarrelsome, thieving, noisy, and the only possible advan- 

 tage the herons could hope to derive from them would be the loud alarm always 

 given by them at the approach of danger. 



Eggs. — [Author's note: Green herons have been known to lay from 

 three to nine eggs, but the ordinary sets consist of four or five eggs; 

 the larger sets are probably the product of two females. The eggs 

 are ovate or oval in shape. The shell is smooth without gloss and 

 the color varies from " pale glaucous green " to " pale olivine. " The 

 measurements of 43 eggs average 38 by 29.5 millimeters; the eggs 

 showing the four extremes measure 41 by 28, 40.5 by 30.5, 36 by 

 27,5 millimeters.] 



Young. — The incubation according to Burns (1915) is 17 days. The 

 young at an early age are expert climbers among the branches of the 

 nesting tree, long before they are able to fly and while the natal down 



