Undertaking an incredible but hazardous journey from South Africa to northern Europe, the migrating swallow can cover more than 200 miles a day at speeds of 17-22 miles per hour. Swallows arrive in the UK in April and May, returning to their southern wintering grounds in September and October.

Seen by northern Europeans as a welcoming sign of the first day of spring, Aristotle warned that "one swallow does not make a spring" given the unpredictability of spring weather. Nevertheless, northbound movements of swallows are closely linked to the northward shift of warm weather that in itself encourages the emergence of insect food. These birds are extremely agile in flight and spend most of their lifetime on the wing.