344 U. S. NATIONAL MUSEUM BULLETIN 211 



hatching of all the eggs required three days; or two might hatch on 

 one day and the third on another day. In a few sets the eggs were 

 marked as laid, and these hatched in the order of laying. The incu- 

 bation period was measured from the laying of the last egg to the 

 hatching of this egg. At four nests the incubation period was 13 

 days; at two other nests, 14 days. 



Young. — The newly hatched grackles had pale salmon-colored 

 skin and bore a sparse but long gray down on the head, back, wings 

 and legs. Their eyes were of course tightly closed, but they could 

 already peep weakly and their bills when opened for food revealed a 

 bright red interior. Their calls of hunger were heeded only by their 

 mothers, for the clarineros were indifferent to this as to every other 

 domestic claim. The only responsibility they assumed was that of 

 guarding the nests. Whenever they espied a man approaching the 

 coconut trees, their sharp tlick lick, flick lick warned the females to 

 flee from their nests, with the result that it was almost impossible to 

 catch sight of them as they incubated or brooded. If we climbed 

 into the crown of a tree which sheltered young grackles, the noise and 

 excitement were immense. Clarineros and sanates, even those whose 

 nests were safe in neighboring trees, circled around and filled the air 

 with excited clucks. There was one particular clarinero, guardian of 

 an isolated palm growing in the corral, who was bolder than all the 

 others. While I rested in the crown of this tree to look at the nestlings 

 under his tutelage, he ventured closer than any of the sanates dared 

 to come, and often alighted near the end of the frond against which 

 I leaned, bending it perceptibly under his weight and making me 

 instinctively clutch another support. He interrupted his clucks with 

 a little tinkling note rapidly repeated, and at times in his anger uttered 

 an indescribably harsh, agonized call, which set the sanates, who all 

 the while had been flying in circles around the tree and complaining 

 in voices weaker than his, into faster movement and louder calling. 

 A single female, mother of nestlings in this tree, perched on a frond 

 and relieved her distressed feelings by giving it angry pecks. 



No hawk or other large bird dared to fly close to our hilltop. Both 

 clarineros and sanates joined in harrying the vultures, both the red- 

 and the black-headed species, which circled too near the palms that 

 sheltered the nests or attempted to alight upon them. They pursued 

 the carrion feeders far down the hillside, striking them repeatedly on 

 the back until they retreated to a satisfactory distance. I am not 

 sure whether they had a natural aversion to birds so unclean, mistook 

 them for hawks, or whether the vultures would actually have eaten 

 the nestlings if given the opportunity. But the grackles even attacked 

 a curassow (Crax globicera), probably the first they ever in their lives 



