The American Cliff Swallow can be seen under the numerous bridges in Iowa with gourd shaped sheltered nests built of dried mud nesting along with a few nests or in extensive colonies. Paddlers and boaters see these sleek, fast iridescent birds swoop to catch insects across rivers, then, fly straight into their nests to feed their little ones or eat “on the wing”. Insects are their main diet along with occasional berries.
The male and female both prepare for their young. Once their 3 – 6 eggs are laid, the incubation period lasts 14 -16 days by both parents. The babies fledge at 21 -23 days. Old nests that have been repaired and re-patched with dried mud is often used. Feathers and dried grasses placed inside create a soft location for their brown dotted, pale pink eggs.
These birds have an almost constant chattering and squeaking vocalization that is magnified and echo under the bridge structures.
They are some of the earliest birds to migrate leaving Iowa in the mid to early August to winter in the southern parts of South America. Migration occurs in the daylight hours in flocks. They will return again from March through May with the male first choosing the nest.
Info credits to: www.audubon.org and www.birthwatchingblog.us
Photo Credits to Wikipedia: 1894 Painting, American Cliff Swallow