Deep Diving in Wild, Free-Ranging Beluga Whales, Delphinapterus leucas

摘要: Three adult female beluga whales, Delphinapterus leucas, were captured during summer in the Canadian high Arctic and equipped with satellite-linked radio transmitters that measured recorded ambient pressure every 20 s. Diving behaviour was divisible into three distinct categories: (1) near-surface, (2) "spike" dives to 20–150 m depth, (3) prolonged, flat-bottomed a maximum depth of 350 m. The duration these prolonged 9.3–13.7 min, but upper bound is known be underestimated. Average descent rates varied between range 1.43–2.20 m/s ascent 1.23 1.84 m/s. Within periods 20 s duration, 2.55 2.35 m/s, respectively. After most rate declined progressively as surface approached, particularly final 100 m. Such usually to, or near seabed probably for foraging. Up 42% an animal's time could spent at depths 8 m more.