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A species of migratory passerine [[bird]] found throughout most of the world's temperate regions. They have a distinctive forked tail and pointed wings. Their feathers are dark blue on the upper side and off-white beneath, with a reddish-brown throat. They are known to build cup-shaped mud nests on vertical surfaces.

h4. External links

"Wikipedia article":https://en.wikipedia.org/wiki/Barn_swallow
barn swallow