A Pygmy killer whale (Feresa attenuata) was noted in distress last Sunday by holiday makers at Birha seaside resort on Sunday 10th January 2016. Attempts to guide the whale back in to the ocean seemed successful, however, the animal beached and died (presumably that evening) approximately 3.5 km’s east of the Birha river mouth.
Photos were sent through to East London Museum scientist Kevin Cole on Sunday by Siani Tinley of the EL Aquarium. He identified the whale as a Pygmy killer whale. The photos illustrated the live animal being attended to by members of the public. On Monday he was informed that the animal had died and he contacted Mrs Kathryn Timms at Birha to give a status update on the stranding. Mrs Timms and Mrs Vass (also from Birha) assisted by securing the whale above the high tide in anticipation of an on-site necropsy (animal autopsy). The stranding was reported to Dr Greg Hofmeyr (Curator of Marine Mammals at Bayworld, PE) who kindly made arrangements at short notice to prepare for a necropsy. This was undertaken yesterday by Greg, Kevin and Bayworld intern Thuli Kom.
This species is not well researched and although Bayworld has records (8 strandings have been recorded for the Eastern Cape to date), the Birha specimen is a first for the East London Museum in 25 years. The Pygmy killer whale can be confused with the melon-headed whale. The distinctive white belly patch and rounded head confirmed the identification differing from the melon-headed whale. On site the mammary slits were noted sexing the animal as female. All measurements were taken and the animal photographed before the necropsy began. The total length of the female was 231 centimetres.
Investigations revealed that there was some discolouration of the lymphatic system, sub-cutaneous parasites and a large growth near the uterus. It was later discovered that the female was carrying a small foetus (a perfect miniature of the adult form measuring 28 cm). This has been secured to be preserved at Bayworld. It may be presumed that the whale was ill.
Dr Hofmeyr calmly shared knowledge about the species and the internal organs with folk from Birha who watched the proceedings. One of the many questions which he answered was why the muscles were so dark in colour. He replied that there was a very high concentration of myoglobin in the muscle. It has been suggested on the basis of this that Pygmy killer whales are a relatively deep-diving species. The Pygmy killer whales occur in tropical and subtropical seas of all major oceans – usually in deep warm waters and rarely near land (except around oceanic islands). No seasonal migrations have been reported for the species and we do not have a good population estimate. They feed on squid and small fish and have been known to attack other dolphins.