Both sexes of barn swallows help build the nest out of mud pellets, dry grass, straw, horsehair, and white feathers.
Both sexes of barn swallow help build the nest, which measures a cup or half-cup.
The nest’s exterior is made from mud pellets mixed with fibers such as dry grass, straw, and horsehair. The nest is lined with dry grass and white feathers. Originally nests were built in caves or on cliffs but now they’re almost always on artificial structures.
• Image | © Tony’s Takes, Some Rights Reserved, (CC BY-NC-ND 2.0)
• Sources | (BirdLife International, 2016; Brown & Brown, 1999; McWilliams, 2000; Perrins, 1989; Roth, 2002; Terres, 1991; Turner & Rose, 1989; The Wikimedia Foundation, 2019)