BIRDS OF PORTO RICO. 



73 



Food. — In 29 stomachs animal matter amounted to 98.57 per cent and vege- 

 table to 1.43 per cent. Two birds had eaten seeds, and a third a small quan- 

 tity of vegetable rubbish, so that this undoubtedly is a regular, though small, 

 part of the food. The largest elements in the animal food were small Homop- 

 tera, flies, and spiders. Nearly all of the stomachs were well filled with solid 

 material, and, though these birds visit flowers systematically, as do all the other 

 hummers mentioned in this report, large numbers of insects are captured within 

 the corollas, and the part that nectar plays in the food is not so great as is 

 usually believed. Certainly they are hungry for meat, as well as sweets. They 

 undoubtedly regurgitate waste matter, in the form of pellets, from which the 

 nutriment has been digested. Several of these, 2 millimeters long by 1 wide, 

 ready to be expelled, were found on opening the stomachs, and in each case con- 

 sisted of a firmly compressed pellet containing chitinous fragments of insects 

 and spiders. 



Small Homoptera were found in 9 stomachs and amount to 20.66 per cent, of 

 which 16.35 per cent were certainly identified as Fulgoridse. Engraver beetles 

 {Platypus sp.) (7.77 per cent) occur in 7 stomachs. These beetles swarm in 

 many localities but little is known of their habits in Porto Rico. Other Coleop- 

 tera, including a leaf beetle, a phalacrid, and a weevil (CaulopMlus sp.), figure 

 as 2.07 per cent. Diptera were found in 18 stomachs and form 28.47 per cent, 

 while ants amount to 6.77 per cent. Other Hymehoptera, present in only 7 

 stomachs, represent 5.63 per cent. Spider remains in 11 stomachs come to 27.15 

 per cent and a single thrips (Frankliniella insularis) (0.05 per cent) completes 

 the count. In taking this thysanopteran a hint is given of possibilities in the 

 destruction of noxious species of economic importance. This large hummer can 

 unequivocally be placed with the beneficial species and, though relatively small, 

 does an appreciable amount of good. 



The following were found in the stomachs of this hummingbird : 



THYSANOPTERA. 





DIPTERA. 





Frankliniella insularis 



1 



Psilopus sp 



5 



HOMOPTERA. 





Dilophus sp 



1 



Ormenis sp 



2 



ARACHNIDA. 





COLEOPTERA. 





Theridula triangularis 



1 



CaulopMlus sp 



1 







Platypus sp 



7 







PORTO RICAN MANGO. Anthracothorax aurulentus (Audebert and Vieillot). 



ZUMBADOR, ZUMZUM, COLIBRI, ZUMBADOR DORADO. 



A common resident species in the island, the Porto Rican mango frequents open 

 localities, hedges through pastures, and bushy growths on open hillsides. It is 

 the common hummer of the coast region, and though a few were found in the 

 mountains, as near Cayey and Aibonito, they were not common in high altitudes, 

 and were never found in dense forests. On Vieques Island they were the most 

 abundant of humming birds but were rare on Culebra Island. They were very 

 pugnacious, continually chasing each other, or even driving away honey creepers 

 feeding in the same localities. In pastures they fed at the large flowers of the 

 emajagua (Paritium tiliaceum), and spent much time in trees, gleaning over 

 the bark, searching the trunks and twigs, and examining them closely. The 

 throat of one taken in a grapefruit grove near Manati was filled with ants. 

 On Vieques Island this species did not mingle with other hummingbirds, and 

 fed largely at the flowers of the molinillo (Leonotis sp.). In the small meadows 

 where these plants grew there were always a dozen or so of the hummers buzz- 



