17-5-2017 ALBUFERA, VALENCIA - BARN SWALLOW (Hirundo rustica)

The barn swallow (Hirundo rustica) is a migratory passerine bird, recognized as the most widespread species of swallow in the world. It is a distinctive bird with blue upperparts and a long, deeply forked tail, known for its graceful flight and agile maneuvers. The adult male of the nominate subspecies is 17–19 cm in length, including elongated outer tail feathers, and has a wingspan of 32–34.5 cm. It is adorned with a rufous forehead, chin, and throat, which are set apart from the off-white underparts by a broad dark blue breast band. The outer tail feathers are elongated, contributing to the iconic "swallow tail."

The barn swallow can be identified by its steel blue upperparts, a rufous face, and a dark blue breast band that separates the rufous from the off-white underparts. The deeply forked tail is a key characteristic, with a line of white spots across the upper tail's outer end. Females resemble males but have shorter tail streamers and less glossy blue coloring. Juveniles are browner with paler rufous faces and whiter underparts, lacking the adult's long tail streamers.

The barn swallow favors open country with low vegetation, such as pastures, meadows, and farmland, often near water. It avoids heavily wooded or steep areas and densely built-up locations. The species typically nests in man-made structures like barns and stables, or under bridges and wharves.

This bird has a vast global range, breeding across the Northern Hemisphere and wintering in much of the Southern Hemisphere. Its distribution spans Europe, Asia, Africa, and the Americas.

Barn swallows are semi-colonial and may settle in groups. They exhibit site fidelity, often returning to the same location annually for breeding. The species is known for its aerial insectivory, catching insects in flight with remarkable agility.

The barn swallow communicates with a variety of calls, including a "witt or witt-witt" and a loud "splee-plink" when excited or deterring intruders. Alarm calls include a sharp "siflitt" for terrestrial predators and a "flitt-flitt" for avian predators. The male's song, used for territory defense and mate attraction, consists of a twittering warble followed by a series of musical notes.

Barn swallows are monogamous and often mate for life, with the male arriving first at the breeding grounds to select a nest site. They build cup-shaped mud nests lined with soft materials, frequently in colonies where each pair defends a territory. The female typically lays two to seven spotted white eggs, with the clutch size varying by latitude.

The barn swallow can be confused with other Hirundo species and the welcome swallow in overlapping ranges. However, its red face and blue breast band distinguish it from African species, and it differs from the welcome swallow by its deeply forked tail and white tail spots.

The diet consists mainly of flying insects, which the barn swallow captures in open areas or follows animals and humans to catch disturbed prey. It may also pick insects from water surfaces, walls, and plants. The species drinks and bathes by skimming over water bodies.

The barn swallow is classified as Least Concern by the IUCN, with an extensive range and large global population. While not endangered, local declines may occur due to specific threats, such as habitat loss or pesticide use. However, the species has benefited from human expansion and the availability of nesting sites.