BIRDS OF PORTO RICO. 



91 



$10 or $15. In the country one was occasionally seen in a rude cage made of a 

 large calabash, with string laced across the opening to prevent escape. 



Food. — In 49 stomachs of the mockingbird animal matter forms 31.21 per 

 cent and vegetable 68.79 per cent. The birds were collected in all the months 

 from December to August save June and are quite evenly distributed through 

 the region under consideration. The smallest quantities of animal matter are 

 found in January and April, 8.5 per cent and 8.14 per cent, respectively. Lepi- 

 doptera, largely cutworms, and Orthoptera compose the bulk of the animal 

 matter and the vegetable food is made up of wild fruits and berries. The 

 relative proportions of animal and vegetable food are practically identical 

 with those found by Prof. Beal in the examination of a large series of mocking- 

 birds from California. 1 



Animal food. — Five of the mockingbirds examined had eaten mole crickets 

 (Scapteriscus didactylus) (3.62 per cent). Mention has been made of this 

 bird's habit of feeding at times in cultivated fields far from its usual cover, 

 and it is undoubtedly during such forays that these injurious insects are cap- 

 tured. Other orthopterous remains in 11 stomachs (4.84 per cent) are less 

 important than the mole cricket, but in capturing them the bird does good 

 service, as all are more or less injurious. The first mockingbird collected, taken 

 at Rio Piedras in December, had eaten a cane root-boring weevil (Diaprepes 

 epengleri) , but this insect was not identified in stomachs subsequently secured. 

 This with other weevils, among which was a coffee leaf-weevil (Lachnopus sp.), 

 In four additional stomachs comprise 1.62 per cent. Other beetle remains (2.06 

 per cent) are all injurious species with the exception of two ground beetles 

 (carabids). Among these others may be mentioned a leaf beetle (Cerotoma 

 denticomis) and a tortoise beetle (Coptocycla signifera), while one bird had 

 captured two wireworms, the immature form of the click beetle. Remains of 

 Lepidoptera, moths in 2 stomachs and caterpillars in 19, come to 12.4 per cent. 

 The latter in at least five instances were cutworms, several being found in a 

 single stomach. These are destructive wherever found. Hymenoptera, largely 

 ants, form 1.85 per cent. A few chalcid flies in one bird were the only bene- 

 ficial species identified. Six birds had eaten spiders and one a mite, which 

 amount to 1.11 per cent. Miscellaneous matter, mollusks, a biting bird louse 

 (Mallophaga) , and earwig remains figure as 2.15 per cent. Stinkbugs, which 

 were secured four times, amount to 0.93 per cent. 



The following insects were identified in these stomachs : 



ORTHOPTERA. 



Plectrotettiao sp 



Homorocoryphus sp 



Scapteriscus didactylus 



HEMIPTERA. 



Thyanta sp. 



COLEOPTERA. 



Selenophorus sp 



Atcenius stercorator 



coleoptera — continued. 



Cerotoma denticomis 

 Coptocycla signifera- 

 Diaprepes spengleri _ 

 Lachnopus sp 



hymenoptera. 



Campsomeris dorsata 



Strumigenys sp 



Pheidole fallax var. antillensis 



Odontomachus hwmatoda subsp. insu- 

 laris 



Vegetable food. — The vegetable food of the mockingbird (68.79 per cent), 

 though more than double the bulk of the animal food, has little economic sig- 

 nificance. With the exception of less than 1 per cent of rubbish, it may roughly 

 be called berries or fruits, all of wild species and none of importance to man. 



iBul. 30, Biological Survey, U. S. Dept. Agr., 1907, p. 53. 



