A BEACHED SOWERBY'S WHALE
Jonathan H. Hooper
BSc, BVM&S, MRCVS
A Sowerby's beaked whale was recently washed ashore
on the beach near Peninver. Little is known of this rarely seen member of
the cetacea. Only forty specimens have been reported in Scotland since records
began.
The Cetacea are divided into two sub-orders: the Odontoceti or toothed whales to which Sowerby's beaked whale belongs, and the Mysticeti, which have no teeth but filter feed on plankton using adaptive baleen plates in the mouth.
Sowerby's beaked whale is also known as the North Sea beaked whale. It belongs to the family of beaked whales (the Ziphiidae) of which there are about twenty distinct species. Four of these species have been reported in British waters: Sowerby's, True's, Gervais' and Cuvier's.
Sowerby's whale resembles a very large dolphin. It has a distinct 'beak' involving elongated flexible jaws which extend from the skull, a relatively small head with small eyes and a long slender body. Although belonging to the 'toothed whales' the teeth are vestigial. In the male there is a single pair of tusk-like teeth which protrude upward from the middle of the lower jaw; they extend backwards with a slight forward curve at the tip. These teeth remain unerupted in the females and juveniles. (Teeth are used as a key feature in the speciation and identification of this group.) There are two V shaped grooves under the throat. The flippers are small and narrow and the dorsal fin sickle shaped and situated about two thirds along the back. The tail fluke has a fairly straight trailing edge. There is a noticeable bulge in front of the oval blowhole on top of the head. There are no external ears but auditory orifices, whilst eyesight is poor the sense of hearing is well developed. The colour of the skin is generally slate grey shading paler over the belly. The smooth skin is hairless and often marked with lighter coloured streaks and arcs which are healed scars. The external sexual organs are hidden within muscular folds of skin to maintain a streamlike form. In the male a small slit near the base of the tail fluke hides the retractable penis; there is a distinct umbilicus in front. In the female the genital opening is much closer to the anal vent. The pair of teats is concealed within slits on either side of the genital area.
The adult male can grow to five metres in length and weigh over a tonne.
Unfortunately only a limited amount of information could be obtained from the specimen beached at Peninver before the storms that had brought it ashore carried it away again. The animal was male and measured 15 ft 8 inches which is a record for this species in Scotland. This was the sixth Sowerby's whale reported in Scotland this year. It had not been dead long, being in excellent condition with fresh blood present in the mouth and genital vent. Rub marks encircling the neck and its general condition indicate that it may well have been caught up and drowned in a net.
Sowerby's whale is distributed right across the North Atlantic and its western range extends from Iceland and the Arctic right down to North Africa. As a group the beaked whales are animals of the deep ocean (pelagic) and are rarely seen in the open sea, hence our knowledge of their biology and behaviour is very limited.
Examination of their stomach contents indicates that they feed at great depths on squid, octopus, cuttlefish and possibly very deep sea fish. The flexibility of their jaws presumably helps to catch agile prey. The teeth play no part in feeding but have probably evolved as a secondary sexual characteristic in males. There is evidence that males use their teeth during intra specific aggression possibly to defend territory and/or access to breeding females. This may explain the longitudinal scars seen on their skin. The circular scars are presumed to be caused by giant squid. It is possible that they hunt singly or in very small groups. A stranding of three individuals was reported on Lewis this year. They appear to communicate with high-pitched whistles. Their movements are poorly understood, but they are rarely seen in coastal waters. It would seem that they breed and also give birth in Spring in their southern waters and migrate north in Summer to feed off the continental shelf. Using information derived from related species we may assume that sexual maturity takes up to nine years, with a gestation period of at least two years. As in all whales a single young is produced.
The following species of Cetaceans have been recorded in waters off the west coast of Scotland: Porpoise, White beaked dolphin, White-sided dolphin, Risso's dolphin, Minke whale, Pilot whale, Bottle-nosed dolphin, Bottle-nosed whale, Common porpoise, False killer whale, Killer whale, Sperm whale, Fin whale, Sei whale, Sowerby's whale, Gervais' whale, Cuvier's whale, White whale, Humpback whale, Blue whale and Right whale.
Relatively few stranded or beached whales have been reported from the west coast of Scotland. This is surprising since the coastline is hugely indented with many beaches, and there is a combination of prevailing onshore westerly winds from the open North Atlantic, and the Gulf Stream. Reportings probably reflect the lack of human population rather than a true record of events.
It is still largely a mystery why whales become stranded or are found beached. Certainly most are washed ashore already dead. Causes of mortality include bacterial, viral or parasitic disease, drowning in nets, and propellor trauma. Toxaemia may be significant with increasing pollution.
Strandings of live whales are often of deep sea species which may have had navigational problems in coastal waters, or are weak due to illness or senility. In cases of mass strandings a close social interaction within a group and altruism (selflessness) probably play a role.
It is evident that we require to know a great deal more about these magnificent animals in order to correlate their population numbers, behaviour, reproduction, disease and pollution contamination status.
At present the Sea Mammal Research Unit of the Zoological Society is conducting a mortality survey of whales (and other sea mammals) around Britain. If you find or hear of a stranded or beached whale in Kintyre please contact Mr R. Reid on 0463 243030 or Mr J. H. Hooper on 0586 552427, or the Coastguard or the Police.
No. 33 Spring 1993
SOMERLED LIVES ON
One of our more interesting correspondents is Dr
David Jackson, an American scholar who is, of all things, a Tibetologist.
He is of the Stewarts of the Park, who almost certainly were closely related
to the Stewarts of the Drum and the Stewarts of Refluich, both of whom claimed
descent from Ardgowan and thus from the Royal line. Not content with this,
Dr Jackson has also traced descent through his maternal grandmother from
Somerled and last summer visited Norwegian relatives who were able to show
him direct descent from a great-grandson of Somerled - Dugal Ruaidhrison
of Kintyre, appointed ruler of the district by King Haakon in 1249. His son
Asle Dugalsson was a prefect in Valdres, Oppland, Norway and the family have
a tree going right back to Somerled through this line.
It is fascinating to learn that there are innumerable descendants of Somerled in Norway to this day and that while he is credited with driving out the Vikings from Scotland his family kept in close touch with their Viking relatives in Norway for four generations and that one at least returned there. Dr Jackson states that Somerled himself married a Norwegian princess, Ragnhild Olavsdotter, in 1140. She was the mother of Reginald, founder of Saddell Abbey.
The island of Cara does not immediately spring to mind as a centre of importance, but on 18th and 19th June 1456 the Lord of the Isles, also descended from Somerled, held court here. Two Notarial Instruments were granted "in the island of Cara near the Monkshaven." On the shore of Kintyre opposite Cara the surveyor Timothy Pont recorded the place-name 'Mungasdale' - the monk's valley - when he visited this part of Argyil between 1585 and 1595. This later became the village now spelled 'Muasdale'. In 1263 King Haakon of Norway anchored off Cara on his way to the Battle of Largs. A Norse saga records that his royal Chaplain died there, and that his body was carried to Saddell Abbey for burial by its Cistercian friars.
No. 33 Spring 1993
Page 2: A Presidential Brush-off // Family History
Page 3: The Bronze Age Cist Burials at Monybachach, Skipness
Page 4: Campbeltown's Glasgow Face
Page 6: The Ritchies of Sanda Island
Page 7: The Haldanes in Kintyre
Page 8: By Hill and Shore - Delights from Mr. Angus Martin
Page 9: Three Interesting e-mails // Tropical Beans // Some Bits and Bobs
Page 10: The Wm Low Supermarket // Carradale Rental 1724