The bar tailed godwit migrates to/from Alaska/New Zealand.
One female bird been tracked flying the southbound leg non-stop in 8 days, a distance of 7270 miles !
She maintained speeds of between 30mph and 44mph, at altitudes of up to 6,500 ft., so had plenty of night flying experience at the end of that trip.
I wonder what the chances are of completing the trip in the northern hemisphere autumn/southern spring without going IMC at some point.