118 BULLETIN 326, U. S. DEPARTMENT OE AGRICULTURE. 



seen taking the nectar from the bucare (Erythrina sp.) and the mufieco (Cordia 

 collococca). Frequently birds had the throat full of this honey and the feathers 

 of the head yellow with pollen. The manzanillo (Eippomane manchinella) also 

 was eaten to some extent. 



Food. — The blackbird or chango is one of the best-known birds of Porto Rico, 

 and its usefulness is almost universally recognized. Some of the current ideas 

 of its food, based on observation alone, are mistaken, but so much good is done 

 in othei; ways that the chango is entitled to a high place in the class of beneficial 

 species. From December to August, 98 of these birds were collected in all parts 

 of Porto Rico and in Vieques, and the contents of their stomachs later were 

 scrutinized carefully. Animal food formed 93.38 per cent and vegetable 6.62 per 

 cent. Blackbirds everywhere are recognized as almost omnivorous, and this 

 species is no exception to the rule, all living creatures of small size being eaten. 



Animal food. — Though commonly considered one of the greatest enemies of 

 the mole cricket (Scapteriscus didactylus), remains of this insect were found in 

 only eight of the birds (0.21 per cent), most of them being eaten in July. The 

 changas taken are nearly all nymphs. Remains of other Orthoptera (19.34 per 

 cent) were found in 42 stomachs and comprise adults of grasshoppers, locusts, 

 and crickets, with a few eggs of roaches, walking sticks, and others. Insects 

 of this class are common in the pastures frequented by the blackbird and form 

 an abundant food supply. Bugs of the homopterous group (2.02 per cent) are 

 composed in great part of cicadas (Proarno hilaris), with a few lantern flies. 

 Stinkbugs (3.32 per cent) were eaten 17 times, and miscellaneous bug remains 

 come to 1.11 per cent. Adult May beetles (Lachnostema sp.) were found in 

 2 instances and larval scarabsaids — white grubs — in 11, all amounting to 1.42 

 per cent. In 23 birds collected in May, largely in cane fields under cultivation, 

 these form 9.47 per cent, and it is under such conditions that insects of this 

 group are exposed to attack. Large numbers of the adult cane root-boring weevil 

 were destroyed, this insect being identified in 39 stomachs. For the entire period 

 this weevil amounts to 9.69 per cent, while for the months of April and May 

 the bulk of it came to 26.67 per cent and 32.13 per cent, respectively. Remains 

 of 11 were taken from one gizzard and from 3 to 6 were not unusual. The coffee 

 leaf-weevil (Lachnopus sp.) was taken by 23 birds and amounts to 1.61 per cent. 

 And though only 13 birds had eaten the slender-beaked weevil stalk-borer (Meta- 

 masius hemipterus) , it constitutes 5.44 per cent. This weevil was secured in 

 March and in the months from May to August, inclusive. Mixed remains of 

 curculios and other weevils total 1.23 per cent and other beetle remains 1.06 per 

 cent. 



Lepidopterous remains (11.15 per cent) figure largely in the food and occur in 

 all the months except April. Thirty-nine birds ate caterpillars and six had cap- 

 tured moths. One stomach contained 16 cutworms as well as 3 adult cane root- 

 boring weevils. Diptera (0.16 per cent) were present in small numbers and 

 Hymenoptera (1.11 per cent) occurred frequently. This group, with only two 

 exceptions, was represented by wasps and considerable numbers of ants, among 

 which fire ants (Solenopsis geminata) occurred three times. Spiders were found 

 in 30 gizzards and mites in 1. Two birds had eaten cattle ticks (Margaropus 

 annulatus). One of these, taken in a brush-filled pasture on Vieques Island on 

 March 21, contained 35 ticks, and the other from Cabo Rojo, killed on August 

 31, had eaten 12 ticks, all greatly distended with blood, so that in this case they 

 were undoubtedly picked from some animal. Snails (Subulina sp. and Planorbis 

 sp.) were eaten regularly and comprise 6.02 per cent of the total. Amphibian 

 remains (5.74 per cent) were encountered in 12 stomachs and were composed of 

 both the common frog and little tree toad. Lizards (16.04 per cent) were found 



