Bioacoustics of Tachycineta leucorrhoa

—By far the most abundant Swallow at all points visited. Arriving from the north early in July, it remains through the summer and does not leave until the following April. Abundant alike in the crowded streets of Buenos Aires and on the monotonous pampas, it is known everywhere the the name Golondrina, and its appearance after the cold weather is hailed as one of the earliest signs of returning summer. Through October and November it breeds at Concepcion wherever it can find a suitable spot, placilig its nest of grass, wool, and feathers in any safe cavity about a dwelling-house or shed, or not infrequently in the deserted nest of a Furnarius or Anumbius . From a nest of the latter bird I took a set of this Swallow’s eggs — five in number—on October 30, the parent birds hovering close about my head as I examined the nest. The eggs are pure white. During the mating season the male has a very pretty song not unlike that of the Eastern Bluebird, though not as long, and seldom delivered without interruption.