Orcas, left, rest in Johnstone Strait off northern Vancouver Island, British Columbia. During these quiet periods, orcas float at the surface, breathing slowly several times over a minute or two, then submerge for three or four minutes before resurfacing in almost the same spot and repeating the pattern. Orcas do not have regular daily resting times and may sleep for only 1 0 to 20 minutes; the longest sleep period observed in the orcas off Vancouver Island was four hours.
Rauno Lauhakangas