NATURE NOTES.

New Zealand Herald, Volume LXVII, Issue 20596, 21 June 1930, Page 25 (Supplement)

NATURE NOTES.

BY J. DItUMMOND, F.L.S., F.Z.S.

GREAT WHALES*

Difficulties in observing the habits of whales are obvious, but in view of the dimensions of the whaling industry much more precise knowledge of these great mammals of the sea might be expected than is possessed. Whalers mostly are intent on their work. If some with inquiring minds study whales from any but the utilitarian point of view, they are reluctant to put their knowledge on paper and print it. Mr. Frank Bullen was an exception, but even his "Voyage of the Cachelot" ranks chiefly as a delightful story of experiences. For. these reasons the world will welcome a large volume on whales in the set of Discovery Reports 'issued by the Discovery Committee, London, -and published by the Cambridge University press in the . dignified style that characterises all its work.

This Discovery Expedition was sent to the dependencies of the Falkland Islands to gather information regarding whales and factors that influence them. It built at South Georgia a laboratory at which observations were recorded.- This expe.dition,- by-the way, was given its title because it bought the vessel that made a stir in New Zealand over a quarter of a century ago when Captain Scott and his National Antarctic Expedition made Lyttelton the headquarters of one of the most daring exploits in history. Refitted for new work in southern latitudes on the other side of the earth, Captain Scott's vessel was commissioned as the Royal Research Ship Discovery.

Whales, in tho first place excite admiration by their prodigious size in these days of small things compared with lumbering creatures of the past. In Genesis they are described in the simplest term as great whales. The blue whale which was washed ashore at Okarito, South Westland, and whose skeleton is in the Canterbury Museum in Christchurch, once hpld the record as the greatest of them all, with a length in a straight line, not over the curves of the body, of 87ft. A blue whale caught by the Discovery Expedition at South Georgia was 95ft. 6in. long. Tho Norwegian Whalers' Association has described five whales 100 feet or more long. These measurements seem to bo unreliable. Still 100 feet is not an improbable length for a blue whale. The largest fin whale caught at South Georgia was 80ft. sin. long.

The calf of a blue whale is about 23ft. long when born, the calf of a fin whale about 21ft. The time of gestation is slightly over ten months with blue whales, and eleven months and a-half with fin whales. Weaning takes place when a baby bluo whale is about 45ft. long. Fin whales are much smaller when they are weaned. In blue whales the nursing time is about seven months. After weaning, the rate of growth slows down. The great sizes of blue whales and fin whales give an impression that they must need an exceptionally long time to grow to maturity, and must live to a great age compared with other creatures. It has been shown that growth is surprisingly rapid during gestation and adolescence, and that one of these whales becomes an adult in an unexpectedly short period.

No direct means have been, found yet to determine the age of any individual whale but it is possible sometimes to judge if one whale is older or younger than another. With younger whales, these are grounds'for guesses at their actual ages. Size is a rough criterion up to a point. There is reason to believe that when a whale reaches a size at which it should be adult, it is about two years of age. A female fin whale 65ft. long probably would not be more than three years and one 78ft. probably would not be less than four years. Beyond this it is impossibjo to go at present.

These papers do not recommend any definite measures by which the whaling industry should he adjusted, but they bring forward facts and inferences from the biology and habits of whales that bc-ar on the effect of hunting the race. A point that specially interests New Zealand, where there has been some outcry against an inordinate killing of whales, is that, in proportion to the value of the products obtained, far more damage is done to the race in temperate and subtropical waters such as South African station? than by whaling stations and factory-ships in the dependencies of the Falkland Islands. The economic extravagance of whaling in South African waters is strongly emphasised.

In blue whales and fin whales, as a rule, the sexes are represented in about equal numbers. At times the sexes are segregated to some extent. Less harm is done to the race by killing a male than by killing a female. Usually, in any number of whales killed, half of them are females. Whales are not scattered evenly over the Southern Ocean. They, are concentrated in areas, although . they are generally on the move. This shows that they keep together on going through some areas, but have a more dispersed formation through other areas, or they travel in herds that spond part of their time in revisiting areas and part in travelling over different routes in the open ocean. Large numbers of whales regularly visit the coastal waters of South Georgia, where food supplies are concentrated. They spend most of their time in migrations, which take them far from land, and most of the whales caught off South Georgia are found within about forty miles of tho coast. If they become scarce within that range, tho whalers do not usually expect to find more by going further from the land.

Correspondents sometimes ask if the kauri ranks among the world's tallest trees. Misleading statements have been published as to the measurements of the world's greatest trees. The latest reliable information is supplied by Mr. E. Maxwell, au experienced forester. Ho does not accept height alone, or height with recorded diameter, as settling the points, as much depends on the taper and the height above the ground at which tho diameters were taken, but he states that the first five places as giant trees seem to be: Tho Californian redwood (Sequoia sempervirens), the kauri, .Australia's giant gum-tree (Eucalyptus regnans), tho Californian big tree (Sequoia gigantia), and the Douglas fir, known in New Zealand as Oregon pine.

Mr. Maxwell regards tho redwood as one "of tho finest trees in the world, if not the finest, as well as one of the most interesting. Its greatest height is three hundred and forty-six feet, with a diameter of twenty-eight foot at the buttressed base. Tho big. tree reaches a height of three hundred and fifty feet and over, and a diameter of more thaw thirty feet. The authentic height of tho giant gum is three hundred and twentysix feet, and a diameter of twenty feet. Tho Oregon pine has reached three hundred feet. Mr. Maxwell gives tho kauri a height of seventy-five feet to tho first branch, but not the completo height. Ho states that, although no great hoight of the kauri has been recorded, compared with the Sequoias and the Eucalypts, it is unique in its almost completo lack of taper. Dr. F. von Hochstetter, who visited New Zealand in tho early days, gives the hoight of the kauri to tho top of tho crown as ono hundred and fifty to one hundred and eighty feet.