BIRDS OF PORTO RICO. 113 



BOBOLINK. Dolichonyw oryzivorus (Linnaeus). 

 Chambergo. 



The bobolink is a rare migrant. Pelzeln (1871, p. 199, footnote) says that a 

 specimen received from the Paris Museum is marked Porto Rico, and Gundlach 1 

 says that it has been taken on Vieques Island, where previously recorded by 

 Cory (1892, p. 110). 



YELLOW-SHOULDERED BLACKBIRD. Agelaius xanthomus (Sclater). 

 Mariquita, Capitan. 



The yellow-shouldered blackbird is a common resident in Porto Rico. There 

 appear to be a few of these birds on Mona Island, as Bowdish (1902-3, p. 12) 

 recorded one, and Cory (1892a, p. 229) received two collected by W. W. Brown, 

 jr., in February and March, 1892. In Porto Rico the species is found mainly 

 below an altitude of 800 feet, and is most abundant in the coastal region, follow- 

 ing inland along the open valleys of the larger streams. Lares (1,200 feet) was 

 the highest point at which they were observed, none being seen in the high 

 central mountain range. In fall, winter, and spring this species moves over the 

 country in small flocks, returning at nightfall to some clump of trees or man- 

 groves to roost, so that it is common to see them flying back and forth morning 

 and evening. The flight at such times is direct, though undulating, and an occa- 

 sional flash of yellow shows on the wing. In the mangrove swamps a small 

 party frequently feeds in close array on the wet ground, or single individuals 

 clamber through the branches absorbed in their search for food. Often they are 

 seen climbing actively up and down the long fronds of the coconut palms, in 

 oriole fashion, or walking sedately among the cattle in pastures. 



The common call note is a sharp chick that is indistinguishable from that of 

 the Porto Rican oriole, and a low chuck is often heard. About the nests they 

 have the sharp, staccato, scolding notes of the red-winged blackbird of the North, 

 given as they circle and wheel overhead. The males do not sing a great deal, 

 though odd, wheezy, or reedlike notes, resembling those of the yellow-headed 

 blackbird, are sometimes heard. 



The breeding season is in May and June, sometimes as early as March, and 

 the young are usually out of the nest by the end of June. The -nests of this 

 species appear always to be built in coconut or royal palms, the birds nesting, 

 as a rule, in small colonies or sometimes in pairs. When the nest is in a royal 

 palm, the male spends most of his time on the tall projecting spike in the crown, 

 where he postures with drooping wings and spread tail, but sings very little. 

 When alarmed, the female flies up and clings to the side of the spike, just below 

 him, both scolding vigorously. All the nests observed were in the axils of the 

 long leaves. The birds feed near the nest, walking about on the ground, and 

 sometimes wading in shallow water. As soon as the young leave the nest, all 

 gather in small flocks, at first remaining near the nesting colony, but as they get 

 stronger on the wing going farther afield. At this season they avoid the intense 

 midday heat by frequenting coffee plantations, clumps of bamboo, and shaded 

 perches. 



In mixed flocks with the Porto Rican grackle, this species feeds in newly 

 plowed fields and in cane fields while the growth is small, following the plow for 

 the grubs and insects exposed. In this way they do much good. Around 

 Manati large flocks of old and young frequent the citrus groves, feeding on the 

 ground and flying up to perch in close flocks in the trees, the dead limbs being 

 preferred. In spring, with the other blackbirds, they frequent the bucare trees 

 (Erythrina sp.), probing the handsome blossoms for their nectar. 



1 Ornithologia Cubana, 1893, p. 118. 

 9767°— Bull. 326—16 8 



