Tasmacetus shepherd, Oliver, 1937

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 : 349

6.

Shepherd’s Beaked Whale

Tasmacetus shepherd

French: Baleine-a-bec de Shepherd / German: Tasmanien-Schnabelwal / Spanish: Zifio de Shepherd

Other common names: Tasman Beaked Whale, Tasman Whale, Tasmanian Beaked Whale

Taxonomy. 7 Tasmacetus shepherdi Oliver, 1937 ,

New Zealand, North Island, “cast upon the beach at Ohawe, in the province of Taranaki.”

This species is monotypic.

Distribution. Poorly known due to a lack of records for the species, but it appears to have a circumpolar distribution within colder waters in the Southern Hemisphere.

Descriptive notes. Total length 600-700 cm; weight ¢.5000 kg (unconfirmed). Body of Shepherd’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 ofthe tail. Coloration is more complex than in most species of beaked whales; Shepherd’s Beaked Whales are dark on the dorsal surface and pale underneath. They also have a pale patch on their forehead and a pair of pale patches running along the side of the body. Adult males may also have linear scars from intraspecific aggression. Rostrum and lowerjaw form a welldefined beak, and there are two grooves on the throat. Shepherd’s Beaked Whale is unique in the family Ziphiidae because it has 17-27 pairs of small, peg-like, functional teeth in both upper and lower jaws. Adult males also have a pair of large conical tusks at the tip of the lower jaw that are presumed to function as weapons in male-male combat. Tusks of females do not erupt from gums.

Habitat. There is no specific information available for this species other than its preference for deep oceanic waters.

Food and Feeding. It is thought that Shepherd’s Beaked Whale primarily consumes deep-water fish rather than squid, but this is based on information from a very small number of individuals. As with other species of beaked whales, Shepherd’s Beaked Whale likely forages at depths greater than 500 m for much ofits life.

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 information available for this species.

Status and Conservation. CITES Appendix II. Classified as Data Deficient on The IUCN Red List. There are no estimates of global population size of Shepherd’s Beaked Whale. [tis rarely sighted at sea and may be naturally rare within its distribution. Like other species of beaked whales,it is potentially affected by ingestion of plastic debris and noise pollution, and it may be caught as bycatch in driftnet fisheries. As a species that is apparently restricted to cooler waters, it may also be vulnerable to effects of climate change. Nevertheless, nothing is known about the form or extent of these potential impacts.

Bibliography. Macleod et al. (2006), Mead (1989c), Rice (1998).

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. Poorly known due to a lack of records for the species, but it appears to have a circumpolar distribution within colder waters in the Southern Hemisphere.