The country for many miles about was arid, excepting only the few irrigated flats near the river where fodder, grain, and vegetables grew luxuriantly. Cacti and thorny shrubbery dotted the slopes, but even these plants of the dry lands were not abundant. Numerous small streams empty into the river during the wet months; but now (November) their courses were dry and parched. [Illustration: Rio Cachimayo at Peras Pampa, Sucre.] [Illustration: Bridge across the Rio Pilcomayo.] Birds were plentiful, but the species varied little from those typical of the uplands. However, they were nesting and this circumstance furnished a new and interesting field for study. One of our first walks took us to an old mill, fallen into decay through neglect. There were hundreds of dollars’ worth of machinery ruined through lack of care and the use of improper lubricants. I have frequently seen machinery of various kinds, ranging from typewriters and sewing-machines to Pelton wheels, seriously damaged because lard or tallow had been used instead of oil, and the wearing surfaces never cleaned. In one of the dust chutes a pair of chestnut flycatchers (_Hirundinea_) had built a flimsy nest of twigs and feathers. It contained two cream-colored eggs speckled with red. The birds remained in the vicinity all day long and paid no attention to the Indians working near by, but when a dog chanced to pass they darted at it furiously, making quick dashes at its head and snapping their bills with a loud, popping noise. Another pair of birds of the same species had a nest above the door of a near-by house. Leaf-cutting finches also called tooth-billed finches (_Phytotoma_), were very abundant. The inhabitants destroyed them whenever possible, as the birds cut the blossoms off the fruit-trees and grape-vines. The bright, saffron-breasted male sat in the top of some thorny bush and uttered queer, unmusical wails that reminded us of the mewing of a forlorn alley cat, while his gray-and-black-striped mate incubated the eggs in a small but compact nest hidden farther down among the spine-armed branches. We examined numbers of the nests; each one contained three eggs of a deep-green color, marked with a few black lines about the large end. Oven-birds built their dome-shaped mud nests on fence-posts or the larger branches of the few poplar-trees that had been planted about the huts for shade, and sang in unison from dawn to dusk as if their hearts were overflowing with happiness. Parrakeets had excavated holes in the face of steep banks, and chattered and quarrelled noisily over their domestic affairs. I suspect that they also appropriated the cavities prepared by swallows, as there seemed to be frequent disputes between these neighbors.