470 PROCEEDINGS OF THE NATIONAL MUSEUM vol. io4 



1952, the interstitial water was less than one percent by weight at the 

 sui-face and at 2- and 4-foot depths). With rare local exceptions 

 moisture becomes available only with the oncoming rains, which, 

 unlike those of northeastern United States, consist of very local show- 

 ers of short duration. Thus, not before the middle of July has enough 

 rain fallen to bring all the deciduous forest into full leaf; in May and 

 June local areas characteristically remain undeveloped and practically 

 without foliage, while but a few miles away in the same type of woods 

 the trees have come into full leaf. 



In addition to this "spotty" development, the leafing of the trees 

 and herbaceous plants in our area may actually occur later than in 

 the New York City area. At the end of April 1953 the seasonally 

 deciduous forest was still approximately 90 percent bare, with rare 

 local exceptions where repeated local showers had fallen in sufficient 

 quantity to open the swollen buds. On May 2 of that year the woods 

 of the New York City area were slightly more in leaf than those of 

 northeastern Venezuela; they developed rapidly and were in apparent 

 full leaf by June 1. However, on June 10, the Venezuelan woods 

 were still quite bare; while most of the buds were swollen, over great 

 areas not more than 25 to 35 percent of the trees had come into leaf, 

 and the herbaceous plants were still undeveloped. Not before the 

 end of June were most of the woods in apparent full leaf, and local 

 areas, perhaps 2 to 10 square miles in extent, still remained bare, 



Description of Region 



General location: Northeastern Venezuela, approximately lat. 9°30' N., long. 64° W. 

 in the States of Anzoategui and Monagas and roughly forming a triangle between San 

 Mateo (Anzoategui) on the north, San Tome (Anzoategui) on the south, and Caicara 

 (Monongas) on the east. 



Principal collecting stations: Cantaura, Anzoategui, elevation c. 815 feet; and 

 Caicara, Monagas, elevation c. 590 feet. 



Principal habitats: (1) Seasonally deciduous forest (approximately 90 percent deciduous 

 during dry season), an extensive sparse woods composed of trees averaging less than 30 feet 

 in height, with occasional taller trees scattered throughout; palms, heliconia, and ferns 

 absent; vines and arboreal epiphytes rare; cactus generally confined to scattered individuals. 

 (2) Savanna, an extensive short-grass plain, dotted with occasional scrubby trees. (3) 

 Lowland seasonal forest, a limited intrusion along the Guarapiche River at Caicara of rather 

 luxuriant forest, composed of trees averaging over 50 feet in height, somewhat over 50 

 percent of the trees being deciduous at the peak of the dry season although often only for a 

 short time; palms, heliconia, and ferns present; arboreal epiphytes common. Characteristic 

 of the study area is the absence of other habitats, such as seacoast, mountains, extensive 

 marshes, or large lakes. Elevation within the area ranges roughly from 350 to 1,500 feet. 



Mean temperature: Approximately 80° F. throughout the year, with very little fluctua- 

 tion, either day to day or month to month, daily temperatures running roughly from a 

 minimum of 70° to a maximum of 90° F. Extremes over a 10-year period were minimum 

 55° F. and maximum 101° F. 



Rainfall: Averages approximately 47 inches (10-year average), with marked seasonal 

 fluctuation and also considerable year-to-year fluctuation. The wet season extends from 

 May to November and in it approximately 90 percent of the rainfall occurs. 



