STAMP ANIMALS—II The massive sperm whale

Press, Volume CXIV, Issue 33455, 9 February 1974, Page 10

STAMP ANIMALS—II The massive sperm whale

By

ARTHUR W. PARROTT

One of the best representations on stamp of the sperm whale is to be found on the 1971 issue of South Georgia, where it is illustrated on the 2d value with the giant equid on which it feeds. The New Zealand centenary issue depicts a sperm whale breaking the surface of the water as it is captured. Although stylised. the 1960 Fernando Po stamps also give a good indication of the size and shape of the ipecies. The sperm whale was made famous by Herman Melville, who wrote the classic book on whaling in which Moby Dick, the albino sperm whale became a legend. Albino whales are extremely rare, but an exce 11 en t example was captured by Norwegian whalers off the coast of Peru during the 1951-52 season The sperm whale is the largest of the toothed whales. It may be recognised by its huge head, which comprises a third of its total length, the absence of a dorsal fin (represented only by a hump on the back), and the presence of a single functional blow-hole on the left side at the tip of the snout. The blow-hole sends up an oblique spout eight or 10 ft high. Under the head is a long, narrow lower jaw fur tiished with 18 to 30 conical teeth on each side. Each tooth is about eight Inches long. There are no functional teeth in the upper jaw — only sockets into which the teeth of the lower jaw can fit when the mouth is closed. In the gums of the upper jaw, however, rudimentary teeth may be present, about one inch in length. These never, or very seldom, erupt through the gums White aa\ The sperm whale s head contains a large cavity in which is stored a clear liquid known as spermaceti.

When this liquid is exposed to the air it immediately solidifies into a white wax Spermaceti was once kept separate from the body oil derived from the rendering down of the blubber, and sold separately for the manufacture of candles. It is now’ mixed with the blubber oil, as there is little or no demand for it todav as a separate oil. The sperm whale’s born; is beautifully streamlined Con tours are rounded with a thick padding of blubber so that all external projections have disappeared, except for a pair of flippers used tor balancing and steering The female is only about half the size of the male. There are many references fn literature to specimens measuring up to 70 ft long, but such giants are extremely rare. Many of these ••measurements” were probably estimated and whaler-, like fishermen are liable tn exaggerate 68ft male The largest sperm whale ever measured was a male of 67ft 1 lin. It was captured near the Kurile Islands, in the North-West Pacific, by » Russian whaling expedition during the summer of 1950. !t was not weighed but it was calculated to be about 78 tons. A 67ft specimen was taken in Japanese waters in 1946. and a 65 ft one was captured near the Faroes Islands bv some Norwegians in 1964. Over 100 years ago mate sperm whales measuring 84ft and weighing up to 100 tons were reported but these have not been verified. However, a specimen raptured off the Galapagos Islands in 1817 must have been huge because it yielded 100 barrels of oil, compared with the average of 50 to 55 barrels. A tooth from this anima! was 9» in. long, 9 in. fn circumference and 91b in weight. In 1897 a sperm whale

reputedly 75ft long was captured' in Aigoa Bay, on the south-east coast of'Cape Province. South Africa. It yielded 3000 gallons of oil, 4000 gallons of spermaceti and a 41b hunk of ambergris. A valuable catch indeed. The skeleton of this whale was presented to the Port Elizabeth Museum. Cows up to 60ft long in older records were evidently wrongly sexed as the largest measured female, captured in the southern ocean during the 1940-41 whaling season, was 40ft 3in. Cows do not generally grow much over 35ft and as that is the legal minimum size limit, few females are taken commercially. Age estimate* It is difficult to estimate how long whales live. Few, if any, would die of old age because once they become sick or feeble they are either killed by predators or, unable to catch their usual prey, starve to death. With age the teeth become worn down and broken and

** *«■#*#** J fins do nothing to help the whale capture or hold its prey. It has recently been suggested that the sperm whale’s age may be ascertained by a detailed study of its teeth. Japanese scientists are using a technique to determine the number of rings laid down in the dentine of the teeth, each ring representing a constant period of time.

This theory was first studied by a Japanese scientist <n 1958. As dentine is deposited there appear layers of unequal breadth and optical density. Comparing the number of dentine layers in the teeth with the length of the whale, the scientist concluded that every year two broad opaque bands in the dentine are formed. These bands are separated by transparent bands: that is, they represent two layers.

I.ater, other scientists measured the increment of the last dentine layers in the teeth of tagged whales. From these data they concluded that fewer than two lentine layers a year were formed by the sperm whale. Further work is required before the method can he used with certainty. 65 years old A specimen captured by a Japanese whaling expedition m 1961, was estimated, using the dentine method, to he 65 years old. The movements and distribution of the sperm whale are controlled mainly by feeding requirements and the breeding cycle. They are almost world-wide in distribution and found in cold as well as tropical waters.

Females are never seen,in antarctic waters, but males are sometimes found in very large pods, sometimes called ‘ harems’’. Large males, averaging about 50ft and weighing 30 to 35 tons, are found in these groups. A 50ft individual yields about 50 barrels of oil

Females and calves are found in warmer waters to gether in pods that may contain hundreds of individuals. These groups, where one old hull is in charge, are often referred to as harems. But recent observations have shown that these harems include many small bulls and the very old are large bulls are evidently ab sent. Old bulls however are present in small bachelor parties. Social groups Those who have studied the sperm whale at sea. can distinguish six main social groups: solitary males, pairs of males, pods of bachelor males, pods of immature whales of both sexes, pods with an old male in charge, and nursery schools. Sexual maturity is strained about eight years in males, when they measure between 35 and 46 ft. The gestation period is between 12 and 13 months and a single calf is bom. It is about 14ft long at birth There appears to be no fixed breeding season and young calves are found throughout the year. The mother nurses the youngster for about six months, by which time it is about. 20ft long. Sperm whales are capable of verv deep and sustained

dives: the average feeding dive, always a deep one, may last about 50 minutes. There are records of them being entangled in submarine telephone cables at depths from 600 to 3700 ft. Entangled in cable A 47ft bull was found entangled in a cable between Ecuador and Peru at a depth of 3700 ft. in 1955. The animals have been recorded ing to a depth of 3200 ft where the pressure is 14001 b per square inch, and they may stay there for an hour or more. Evidence suggests they may be able to dive considerably deeper than this — even to 10,476 ft. Dr Malcolm Clarke timed two sperm whales dives in August, 1969. One’s dive was 53 minutes and the other lasted 1 hour 52 minutes. This, I believe, is the longest duration of a dive on record. The principal food of the sperm whale is squid. Other marine animals such as groper, ling and lanternfishes, are found in the stomachs of captured specimens, but they are insignificant compared with the quantities of squid consumed. The mysterious substance known as ambergris or "grey amber" is invariably associated with the sperm whale. This fatty substance is formed in the digestive tract of the whale and although its origin is not definitely known, it is supposed to be the result of irritation set up by the horny beaks of the squids on which the whale feeds, becoming embedded in the walls of the stomach and intestines. It looks somewhat like mottled soap. Beaches near sperm whale feeding grounds yield a considerable supply of ambergris — Mason’s Bay, Stewart: Island, is said to be one of them. Generally, the largest pieces are taken from the digestive tracts of captured whales, A piece from an animal captured by a Norwegian whaling expedition in Australian waters in 1912 weighed i 0031 b and sold for 23,000

Once a valuable raw material, ambergris was used in the manufacture of perfume because of its peculiar, prop erty of fixing and holding the scent. A synthetic preparation is now used for this purpose and consequently the market price of ambergris has been reduced considerably.

Whaling has taken its toil on the sperm whale population: last century large migratory schools were frequently seen, but today only very small pods of two to five individuals are encountered. They cruise at only about four knots, but when necessary can attain speeds of 10 knots. (To be continued).

Postage stamps depicting the sperm whale are: Fernando Po, 1960, 10c + 5c and 30c + 10c (stylised); Neu Zealand, 1956, 2p Southland centenary issue; South Georgia. 1963, 2p definitive issue; South Georgia, 1971, 2p definitive issue; St Pierre and Miquelon, 1969, 3fr definitive issue; Australian Antarctic Territory, 1973, $l, attacking giant squid.