Alone female Western North Pacific grey whale has set a record for long-distance migration, according to a study. Nicknamed Varvara, the nine year-old whale was tagged off Russia's Sakhalin Island in 2011. She crossed from the northwestern to the north eastern side of the Pacific and followed the western Canadian and US coast to breeding grounds off Baja California, Mexico. She swam 10,880km in 69 days"the longest recorded distance travelled during a mammal migration" scientists said. She returned home on a more southerly route, completing a 172-day, 22,511 km trek, also a record. for round-trip migration. Until now, the acknowledged for mammal migration has been a hump back whale which made a one-way 9,800km trip from waters off Brazil to Madagascar. AFP