Rare pygmy sperm whale discovered on Dorset coast
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.
This unfortunate animal 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. The 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.
The fact that we know so little about these whales highlights the importance of protecting our oceans. You can support The Wildlife Trusts’ aim to win protection for 30% of our land and sea by 2030 at wildlifetrusts.org/30by30.
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. Fortunately, by liaising over this stranding with CSIP it was possible to record and recover it 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.