HOW WHALES SLEEP

Hokitika Guardian, 9 August 1927, Page 3

HOW WHALES SLEEP

Where and when do whales sleep? This question is asked and partly answered by Robert V . Gray, of Exniouth, in a report to the English scientific journal, “Nature.” Mr Gray is the son of an old whaling captain, and has had many opportunities for first-hand observation in the northern seas. Whales are warm-blooded creatures, refilled to the fur-bearing animals that live on land rather than to the fishes i of their natural habitat; it is assumed, therefore, that they require sleep In ( much the same manner as land-living j mammals. Once in a while they have been caught asleep at the surface by whalers—usually with fatal results to the whale. A whale suddenly aroused by being harpooned thrashes about fox a few moments instead of diving at once, as whales do upon being harpooned while they are awake. Foi this reason, old-time whai'ers used to arouse sleeping whales by rapping sharply on their boats before easting their harpoons, because the startled lloundering ol the monsters might smash or swamp their craft. But whale found sleeping at the surface are a comparative rarity, and Mr Gray agrees with other whalers in believing that they require more sleep than they have been observed to take. He is of the opinion that they can sleep under water, and quotes statements to the effect that they may sleep under lee fields.

But sleeping under water, for an airbreathing mammal, has its difficulties. Mr Gray inclines to the opinion that a sleeping whale, whether at the surface or submerged, does not breathe at ail. but closes its blow-hole tightly to exclude water and slumbers while literally holding its breath. He calls attention to the fact that harpooned whales frequently remain submerged for as much as an hour, exerting every muscle in their light, for life, and reasons that the very much reduced breath-requirement of the sleeping aniI mals would make it possible for them to remain submerged and sleeping for several hours before it became necessary to come up and “ blow.”