The Barn Swallow is distributed throughout most of the world. Birds seen in South America are migrants from North America that arrive in about September and leave around March / April.

The sub-species in the Americas is H. r. erythrogaster which differs from the nominate found in Europe and Asia by having only a partial black breast band, having a more extensive rufous throat and having rufous to chestnut underparts below the breast band compared to whitish on the nominate.

Another point to note is that while they are in South America they are moulting and even juveniles perform a complete moult at this time. As a result they are not usually so colourful and neat as when in their breeding plumage.