472 PROCEEDINGS OF THE NATIONAL MUSEUM vol. i04 



better conditions, but others {Vireo virescens, Cyclarhis gujanensis) 

 may perhaps shift into the more advanced portions to nest. In any 

 event, the local conditions differ from those of the Temperate Zone 

 (New York City region), and further data on the breeding behavior 

 of bu'ds under these conditions should prove of interest. 



Another factor that may affect the breeding seasons is abundance 

 of food. This would appear to be most important when the young 

 are still in the nest, because the nestlings possibly eat more during 

 this period of rapid development than afterward, and because the 

 parents must secm*e sufficient food for several, whereas later each bird 

 fends for itself. We should, therefore, expect few insectivorous birds 

 to nest before June. Our records are especially weak in respect to 

 May and June, but it appears that many insectivorous birds com- 

 mence nesting well before June. 



Regarding insect abundance, counts at the collector's door-light at 

 Anaco, Anzoategui, will give a rough idea of the increasing numbers. 



April 10-20: 1 cicada; 1 small moth. 



May: no record. 



June 10: 5 cicadas; 1 small scarab; 1 small hemiptera; 3 small moths. 



June 15: 3 cicadas; 1 small scarab; 5 small, other beetles; 5 small moths; 1 

 ichneumon (?). 



June 17: first swarm of tiny beetles (thousands). 



June 20: swarm of small insects, mostly moths and beetles; 6 large moths; 

 3 cicadas; about 20 larger Coleoptera of at least six families (Cicindelidae, Cara- 

 bidae, Scarabaeidae, Hydrophilidae (?), Cerambycidae, Elateridae); about 10 

 Hemiptera of at least two families (Reduviidae, Pentatomidae) ; about 20 

 Hymenoptera (winged ants and Cephidae (?)). 



Since the foregoing paragraphs were written Pinto (1953, pp. 111- 

 222, especially pp. 118-129) has published less complete but perti- 

 nent data from the region of Belem, Pard, Brazil, and Davis (1953, 

 pp. 450-467) has reported more detailed and more complete data on 

 conditions in British Guiana. In the latter country the seasonal dis- 

 tribution of rainfall differs from that of northeastern Venezuela; pre- 

 cipitation reaches a high peak in May, drops steadily to a low in 

 September and October, and then rises to a prominent, though second- 

 ary, peak in December, whereas in Venezuela the high peak occurs in 

 June-August, after which the rainfall declines steadily to a low in 

 February and March, with a slight decrease in the rate of decline in 

 September and October. In other words, there are two definite rainy 

 and two dry seasons in British Guiana, while in Venezuela, as in 

 Trinidad, there is but one of each. In this connection, it may be noted 

 that the curve we have shown of actual recorded avian breeding activ- 

 ity in our study area (fig. 103) shows a slight secondary peak in Sep- 

 tember and October, which agrees better with the picture presented by 

 Davis for British Guiana than does our second curve (fig. 104) in which 

 this secondary peak has been smoothed down. However, there appears 



