Feeding habits of Baird's beaked whale Berardius bairdii, in the western North Pacific and Sea of Okhotsk off Japan

Abstract

We examined the stomach contents of 26 Baird's beaked whales caught off the coast of Japan by small‐type coastal whalers. The main prey for these whales was rat‐tails and hakes in the western North Pacific. Pollock and squids were also important food in the whales collected from the southern Sea of Okhotsk. The prey species found in the stomachs of the whales were almost identical to those caught in bottom‐trawl nets at depths greater than about 1000 m in the western North Pacific, which suggests that the Baird's beaked whale forages for prey at depths of about 1000 m or more. Baird's beaked whales in the western North Pacific migrate to waters of 1000–3000 m in depth, where demersal fish are abundant. This implies that Baird's beaked whales migrate to waters where demersal fish, especially rat‐tails and hakes, are abundant. Although there is limited information on the feeding habits of ziphiid whales, they are generally thought to prefer squid. The present data suggest that demersal fish are also important prey for ziphiid whales.

Diving behaviour of a Baird’s beaked whale, Berardius bairdii, in the slope water region of the western North Pacific: first dive records using a data logger

“…, 1997; Walker et al. , 2002; Ohizumi et al. , 2003), the actual underwater behaviour is not well understood because of the difficulty in collecting data by direct observation.…”

“…Geographical distribution and stomach contents of Baird’s beaked whales suggest their remarkable ability for deep diving (Ohizumi et al. , 2003).…”

Declining Abundance of Beaked Whales (Family Ziphiidae) in the California Current Large Marine Ecosystem

“…Mesoplodon whales eat smaller prey and more fish than Z. cavirostris , which seems to feed mainly on larger cephalopods [57]. B. bairdii feed substantially on demersal fishes, although cephalopods appear important as well [57]–[59].…”

The red flying squid (Ommastrephes bartramii): A review of recent research and the fishery in Japan

“…It is an important prey of northern fur seals (Callorhinus ursinus) in the central North Pacific (Mori et al, 2001), and a minor prey of short-beaked common dolphins (Delphinus delphis; body length range, 155-190 cm) in the western North Pacific (Ohizumi et al, 1998) and of Baird's beaked whales (Berardius bairdii; body length range, 8.85-10.48 m) off central Japan in summer (Ohizumi et al, 2003a). Dall's porpoises (Phocoenoides dalli), however, appear not to feed on O. bartramii in the North Pacific during summer (Ohizumi et al, 2003b).…”