Barn Swallow

The barn swallow is the most widespread swallow in the world, found on every continent. The adult male of the nominate subspecies is 17–19cm long, including 2–7cm of tail streamers, with a wingspan of 32–34.5cm and a weight of 16–22g. It has steel-blue upperparts, a rufous forehead, chin and throat separated from off-white underparts by a broad dark blue breast band, and a deeply forked tail with a line of white spots. Females have shorter streamers and are less glossy, and juveniles are browner and lack the streamers (Wikipedia, general species account).

It is a bird of open country that feeds on insects caught in flight and normally nests on man-made structures, building a cup of mud pellets, so it has spread with people. Eight subspecies breed across the Northern Hemisphere, and six of them winter across much of the Southern Hemisphere (Wikipedia, general species account).