Dorset Wildlife Trust was alerted to the dead-stranding of a pygmy sperm whale on Friday 10 December. The pygmy sperm whale washed ashore on Thursday and is one of only around 10 recorded sightings ever of this elusive, dolphin-like creature in the UK.

Pygmy sperm whales are a type of toothed whale, like sperm and killer whales, but only measure up to a maximum 3.35m long, making them more dolphin sized. Although they are widespread around the globe, they prefer deep water, are not sociable and keep a very low profile when at the surface.  As a result, they are one of the most rarely observed of all cetaceans.

Pygmy sperm whales, Kogia breviceps, have a dark grey back with a paler, sometimes pinkish underside. The blunt, rounded head is distinctive, as is the under-slung jaw with tiny, needle-shaped teeth only on the lower jaw. It feeds on deep-diving squid and fish and has a very unusual survival strategy in that it expels a dark fluid to mask its escape when threatened.

The whale on Hive Beach was just a youngster measuring less than 1.8m long and may have died at sea and been carried inshore by Storm Barra last week.

Its body has been collected by the Cetacean Strandings Investigation Programme (CSIP) at the Natural History Museum in London for further investigation.

The cause of death was not obvious, although some damage to the skin and fins was sustained, possibly from washing ashore on the pebble beach. There were also some ‘rake’ marks inflicted by another species of cetacean such as a pilot whale, although whether this was prior to or after death is currently uncertain.

Dorset Wildlife Trust records all dead-stranded cetaceans (whales, dolphins and porpoises) in Dorset and works closely with the CSIP to report and recover fresh and rare specimens for post-mortem examination and to discover more about them and the causes of death. It was possible to record and recover the dead whale quickly for further investigation.

If you find a live-stranded cetacean, please contact British Divers Marine Life Rescue 01825 765546 – 24 hours, urgently to engage a rescue. Never try to return it to the sea. If you find a dead-stranded animal, inform Dorset Wildlife Trust on 01305 264620 (Monday-Friday, 9am-5pm) or CSIP on 0800 652 0333.