28 BULLETIN 17 6, UNITED STATES NATIONAL MUSEUM 



one of the architect's peculiarities. A hole had been left in the centre of the 

 nest and only recently filled with leaves whose fresh green color testified that 

 they had been cut and placed there later than the others forming the carpeting 

 to the bottom of this common incubator. 



Alden H. Miller (1932) writes of his experience with the nesting 

 habits of the groove-billed ani in El Salvador : 



Several nests were watched from the time there was one egg until there 

 were nine, or in one case eleven, eggs. The eggs were deposited regularly at 

 one day intervals and there was no certain indication in any of the sets, of two 

 females contributing to the same nest as has been claimed by other observers. 

 My findings, however, do not prove conclusively that community nests may not 

 exist, at least occasionally. Incubation is uniform within a set and, correspond- 

 ingly, birds were found to be incubating regularly only after the sets were 

 completed. In the set of thirteen the eggs were resting in three layers in the 

 necessarily ample cup of the nest. 



Nest sites were from two feet to twenty-five feet above ground in almost 

 any kind of bush or tree. Usually they were located between six and twelve 

 feet above ground in thorny tangles or close twiggery. One nest was found, 

 however, in an open crotch of a fan of a royal palm. Adult birds are not 

 much in evidence around nests which are being built or around sets of in- 

 complete eggs. When flushed from sets of complete eggs, they may approach 

 within five feet of the intruder and utter their feeble, squeaking notes of 

 protest. 



A. J. van Rossem (1938) found several nests, on July 29, 1925, "in 

 the mimosa scrub in the marsh along the north shore of Lake Olo- 

 mega," in El Salvador. "These nests were all in similar situations, 

 that is, they were rather conspicuously placed in mimosa bushes and 

 more than six feet above the mud or water." 



Mr. Skutch devoted considerable time to studying the communal 

 nesting habits of the groove-billed ani. He found them to be among 

 the latest birds to breed, remaining together in small flocks from 

 February to May while the other birds of the region were raising 

 their broods. During June he watched the construction of a com- 

 munal nest, on which three pairs worked in perfect harmony, op- 

 erating in pairs and not as a unit. One of the pair remained on the 

 nest while its mate brought in the material. There was not the least 

 jealousy between the pairs, and "two or more pairs often perched 

 quietly in the same bush. Each pair preferred to work alone at the 

 nest, and if a second pair flew into the nesting tree, the first often 

 quietly withdrew. This was not always their conduct, and some- 

 times one of the second pair (probably the female) took a place on 

 the nest beside one of the first pair, while their two mates perched 

 near by, or else brought them sticks. 



"The normal set of eggs for each female is three, or more com- 

 monly four. Nests belonging to a single pair generally contain this 

 number, and the nests belonging to two pairs, which I encountered, 

 contained a maximum of eight. Once I found a nest with 12 eggs, 



