Humpback whales back in Britain, with rise in sightings from Kent to Isles of Scilly

More sightings may be a positive sign for growing population but also indicative of effect of climate change

The slap of an enormous tail upon grey waters as a humpback whale leaps from the sea is becoming an increasingly possible - although still rare - natural thrill around Britain.

The 30-tonne, 15 metre-long migratory giants are being spotted in growing numbers and locations this winter from Kent to the Isles of Scilly.