Mesoplodon hectori (Gray, 1871)

Russell A. Mittermeier & Don E. Wilson, 2014, Ziphiidae, Handbook of the Mammals of the World – Volume 4 Sea Mammals, Barcelona: Lynx Edicions, pp. 326-357 : 353

14.

Hector’s Beaked Whale

Mesoplodon hectori

French: Baleine-a-bec de Hector / German: HectorZweizahnwahl / Spanish: Zifio de Hector

Other common names: Skew-beaked Whale

Taxonomy. Berardius hectori Gray, 1871 ,

New Zealand, Wellington, “killed in Tatai [sic] Bay [= Titai Bay], Cook’s Straits.”

This species is monotypic.

Distribution. Most records come from either New Zealand or the Atlantic coast of South America, but also recorded in Tasmania, Western Australia, and South Africa; distribution remains unclear due to the small number of confirmed strandings. There are no records of this species between New Zealand and the Pacific coast of South America, but it is unclear whether this represents a break in distribution or a lack of research activity in this region. Earlier records from the Pacific coast of USA have since been reclassified as Perrin’s Beaked Whale ( M. perrini ).

Descriptive notes. Total length 343-443 cm; weight ¢.500 kg (unconfirmed). Body of Hector’s Beaked Whale is spindle-shaped, with greatest girth around its midpoint. Flukes are wide in relation to body length, and tailstock is compressed laterally. Dorsal fin is small and set approximately two-thirds the distance between tip of the beak and end of the tail. Coloration is typically dark brown, dark gray, or black dorsally and pale underneath. Rostrum and lowerjaw form a beak thatis indistinct from the low sloping forehead. There are two grooves on the throat. Adult males have a single tusk on each side of the lowerjaw; these tusks are positioned close to tips of mandibles; they are approximately triangular in shape and are laterally flattened.

Habitat. Presumably waters greater than 200 m deep. Nothing further is known about habitat preferences of Hector’s Beaked Whale.

Food and Feeding. Hector’s Beaked Whale is known to consume deep-water cephalopods and may consume other deep-water organisms such as fish and invertebrates. Theylikely forage at depths greater than 500 m for much of their lives.

Breeding. There is no information available for this species.

Activity patterns. There is no information available for this species.

Movements, Home range and Social organization. There is no specific information available for this species, but Hector’s Beaked Whaleslikely occur in small groups.

Status and Conservation. CITES Appendix II. Classified as Data Deficient on The [IUCN Red List. There are no estimates of global population size of Hector’s Beaked Whale. Like other species of beaked whales, Hector’s Beaked Whale is potentially affected by ingestion of plastic debris, bycatch in driftnetfisheries, climate change, and noise pollution. Nevertheless, nothing is known about the form or extent of these potential impacts.

Bibliography. Dalebout et al. (2002), MacLeod et al. (2006), Mead (1989b).

Figures

1. Baird’s Beaked Whale (Berardius baiwrdu), 2. Arnoux’s Beaked Whale (Berardius arnuxu), 3. Cuvier’s Beaked Whale (Ziphius cavirostris), 4. Northern Bottlenose Whale (Hyperoodon ampullatus), 5. Southern Bottlenose Whale (Hyperoodon planifrons), 6. Shepherd’s Beaked Whale (Tasmacetus shepherd), 7. Longman’s Beaked Whale (Indopacetus pacificus), 8. Hubbs’s Beaked Whale (Mesoplodon carlhubbsi), 9. Stejneger’s Beaked Whale (Mesoplodon stejnegeri), 10. Pygmy Beaked Whale (Mesoplodon peruvianus), 11. Perrin’s Beaked Whale (Mesoplodon perrini), 12. True’s Beaked Whale (Mesoplodon marus), 13. Strap-toothed Whale (Mesoplodon layardii), 14. Hector’s Beaked Whale (Mesoplodon hectori)

Distribution. Most records come from either New Zealand or the Atlantic coast of South America, but also recorded in Tasmania, Western Australia, and South Africa; distribution remains unclear due to the small number of confirmed strandings. There are no records of this species between New Zealand and the Pacific coast of South America, but it is unclear whether this represents a break in distribution or a lack of research activity in this region. Earlier records from the Pacific coast of USA have since been reclassified as Perrin’s Beaked Whale ( M. perrini ).