Manx shearwaters migrate from Wales to Brazil, leaving behind their chicks, which follow them as soon as they can fly. One made the trip in 16 days, averaging 460 miles per day. A Manx shearwater was taken from Wales to Boston, far off its normal migratory route. Yet it returned to its home burrow in Wales 3,200 miles away in 12 1/2 days.

The Manx shearwater had to know where it was when released in Boston to determine the direction to Wales.