Manx Shearwaters are long-lived. One was trapped in Northern Ireland in 2003 which had been ringed in 1953. And it would have had to have been an adult to have been ringed, so was at least 55 years old.
Given their lifespan and migration patterns they could well fly over 5 million miles in a lifetime.
Half the population live on Skomer, which I visited last week, but they only return to their burrows at night, so I didn't see any. (A disappointment more than made up by the puffins).