Nesting biology of the blue-and-white swallow (pygochelidon cyanoleuca) in northeastern ecuador

Abstract

The Blue-and-white Swallow (Pygochelidon cyanoleuca) is found in open country from Costa Rica to Patagonia. With a broad geographic range and both migratory and resident subspecies, P. cyanoleuca likely exhibits substantial variation in life history and breeding biology. Here, we present data on its nesting in northeastern Ecuador. From the years 2003-2009 we made general observations of breeding biology and detailed observations at 16 nests. We measured dimensions of four nests, took a time series of size and mass measurements on 12 eggs and five nestlings, and videotaped 110.5 hours of behavior at one nest. We found that nesting activity occurred from June to January, with no records in July. Mean measurements (cm ± SD) of four nests were: outer diameter, 11.3 ± 1.0; outer height, 3.5 ± 0.7; inner diameter, 5.3 ± 0.5; inner depth, 2.6 ± 0.3. Clutch size was always three eggs that were a plain white color or had very small, light brown speckles. Twenty-seven eggs of unknown age had mean measurements of 17.4 ± 0.6 mm long, 12.7 ± 0.3 mm wide. A subset of 12 eggs with accurate mass data weighed 1.4 ± 0.1 g. Based on observations of two color-banded birds at a nest, both adults provisioned young. We recorded a feeding rate at the nest of 6.1 feeds per nestling-hour. These data are largely consistent with previous studies of P. cyanoleuca and Hirundinidae more broadly.