342 U. S. NATIONAL MUSEUM BULLETIN 211 



hurried took twice as long. The ample cups measured from 4 to 5 

 inches in internal diameter and from 2% to 4 inches in depth. 



Eggs. — The female began to lay 3 or 4 days after finishing her nest. 

 The earliest egg in the colony appeared on March 3, and during the 

 next week many birds started to lay. Usually an egg was deposited 

 each day until the set was completed, rarely 2 days elapsed between 

 the laying of the first and second eggs in sets of two. Of 49 nests 

 which we were able to reach at "Alsacia," 33 contained 3 eggs each, 

 15 contained 2 eggs, and there was a single set of 4. 



The big, glossy eggs of the boat-tailed grackle are strikingly marked 

 and usually very beautiful. The ground color varies from bright blue 

 to very pale bluish gray, on which are dots, blotches and intricate 

 scrawls of brown and black. The blue ground color of some eggs is 

 locally washed with shades of brown or pale lilac. It would be tedious 

 to describe all the diversities of pattern that fall within this general 

 scheme ; for the variation is so great that, if all the eggs in a populous 

 colony were mixed together, each bird might conceivably be able to 

 recognize her own by its distinctive markings. The measurements of 

 62 eggs temporarity removed from the nests at "Alsacia" average 33.6 

 by 23.0 millimeters. The eggs showing the four extremes measured 

 36.5 by 23.4, 32.9 by 24.6, 31.0 by 22.2 and 34.1 by 21.4 millimeters. 



Incubation. — As she had built alone, so each sanate incubated 

 alone, without help from a clarinero. But long before the first egg 

 hatched, calamities began to occur. The earliest builders, who had 

 seized upon the most coveted nest sites between the youngest fronds, 

 found to their sorrow that this supreme and most desired position had 

 one disadvantage which to the sober-minded would have outweighed 

 all of its manifold attractions. It was inevitably unstable; for here 

 the nests were supported between two fronds which still grew and bent 

 outward in opposite directions as new leaves pushed up between 

 them at the apex of the palm. The coarse fibers of the outer wall of 

 the nest were, as we have seen, wrapped around the ribbonlike seg- 

 ments of one or both of the supporting fronds. But these formed an 

 entirely inadequate foundation; the slender ribbons sank down under 

 the weight of the heavy, dung-lined structures, and the eggs rolled 

 out even when the whole nest did not fall. The swaying of the fronds 

 in the wind hastened the undoing of the nests. We attempted to 

 save many by tying them securely with cord as close as possible to the 

 original position; but even with this help it was difficult to make them 

 remain in their precarious situations, and most came to disaster. 

 Of the many birds which had built between the youngest fronds, only 

 one to my knowledge succeeded in bringing out her nestlings alive, 

 and then only because we tied up her nest when it began to lean. 

 Yet despite the terrible example constantly before her, with infinite 



