74 



BULLETIN 326, U. S. DEPARTMENT OF AGRICULTURE. 



ing rapidly around, chasing each other back and forth, or probing the flowers. In 

 March the young on Vieques were full grown, but on Porto Rico they appear to 

 nest in May and June. A full-grown young of the year was taken near Ciales 

 July 13. 



Food. — Thirty stomachs examined represented the months from January to 

 August, with the exception of June. Animal matter forms 9S.57 per cent and 

 vegetable 1.43 per cent, the latter consisting of a large seed of panic grass 

 found in one stomach. The bulk of the animal food is composed of small 

 Homoptera, Diptera, and Hymenoptera. 



Small Homoptera found in 15 stomachs amount to 33.35 per cent. 13.21 per 

 cent being recognized as lantern flies (Fulgoridse). Leaf hoppers (Jassidse) 

 were taken twice. Snout beetles come to 3.26 per cent, and other Coleoptera, 

 death-watch and leaf beetles mainly, to 5.97 per cent. One mosquito was iden- 

 tified. Remains of Diptera, which as a whole amount to 16.93 per cent, occur 

 in 14 stomachs. Hymenoptera amount to 29.81 per cent ; ants were found in 5 

 stomachs and other Hymenoptera in 26. Spiders were eaten seven times and 

 amount to 7.80 per cent, while miscellaneous matter, mainly earwig remains, 

 totals 1.45 per cent. 



This large hummer has a rather varied insect fare and, though many Hymen- 

 optera are eaten, they are compensated for by the injurious leaf hoppers, 

 lantern flies, and beetles consumed. Though small, the hummingbirds have 

 their own niche in the economy of life and do an appreciable amount of good. 

 Movement as rapid as theirs requires quick consumption of fuel, and their 

 stomachs, though small, must be filled frequently to keep up with the demand 

 for muscle-building nutriment. In the quantity of small Homoptera eaten, the 

 present species ranks near the warblers, and in the variety of beetles destroyed 

 it exceeds any of the other hummers found in Porto Rico. 



The following were identified in these stomachs : 



HOMOPTERA. 



Or 7)1 en is sp. 



COLEOPTERA. 



Lolerus sp 



Haptoncus luteolus. 



Catorama sp 



Cerotoma sp 



Psilopus sp 



Conicera aldrichi. 



HYMEXOPTERA. 



Solenopsis geminata 1 



ARACHXIDA. 



Epeira sp 2 



Epeira theii 1 



JAMAICAN BLACK SWIFT. Xeplicecetes niger jamaieensis (Bidgway). 



GOLOXDRIXA, VEXCEJO. 



The Jamaican black swift is apparently a rare resident species. Gundlach 

 (1878, p. 200) records it from Lares, Quebradillas, and Utuado. and notes young 

 birds from the latter locality. One was hawking about the sugar experiment 

 station at Rio Piedras on December 16, 1911, but the species was not again 

 seen until May 4. On that date near Yabucoa I saw a pair circling swiftly 

 back and forth, high above a pasture. One was shot as it passed overhead, and 

 came tumbling down, its companion following. The latter circled by once or 

 twice like a flash and then disappeared. The bird taken was only winged, and 

 showed a curious semicircular tuft of feathers in front of and above the eye 

 that strongly resembled the facial disk of an owl. This is not noticeable in 

 skins. Single birds were seen three times during the latter part of June about 

 Lares. 



Food. — Two stomachs of this swift contain animal matter only, composed 

 mainly of ants, which in one case amount to 91 per cent and in the other to 45 

 per cent. One species was identified (JVasmannia auropunctata), and one bird 



