Although the geographic range of this species is not clearly known, Tasmacetus shepherdi (Shepherd's beaked whale, Tasman whale) probably has a circumpolar distribution in temperate waters of the southern hemisphere. All known specimens have been found on beaches in New Zealand, Australia, Brazil, Tierra del Fuego, Argentina, Chile, and the Galapagos Islands (Evans 1987, Tinker 1988).
Biogeographic Regions: indian ocean (Native ); atlantic ocean (Native ); pacific ocean (Native )
The body of these whales is around 6-7 meters in length. The head is small with a long, narrow beak. The dorsal fin is small and is located 1/3 of the body length from the tail. The tail fluke is not notched, and the flippers are small and oval in shape. The back is uniform grayish-brown in color, fading to nearly white on the underbelly. Since very few of these whales have been seen while alive and body colors quickly darken following death, the true coloration of Tasmacetus shepherdi is not known (Evans 1987, Tinker 1988).
Shepherd's beaked whale can be easily distinguished from other members of the family Ziphiidae by the presence of 17-29 conical teeth in both the upper and lower jaw. Males possess two additional teeth on the anterior most part of the lower jaw. These teeth, described as possessing "bulbous bases and conical crowns", are larger than the homodont cheek teeth, and are separated from the cheek teeth by a 4 cm diastema. One tooth sits on either side of the mandibular symphysis (Walker 1975, Evans 1987, Tinker 1988).
The blowhole is crescent in shape and is asymmetrically located on the left side of the top of the head. The eye sits directly below the blowhole. The first five vertebrae are fused and the first through seventh pairs of ribs possess two heads (Evans 1987, Tinker 1988).
Range mass: 5600 to 6500 kg.
Range length: 6 to 7 m.
Other Physical Features: endothermic ; bilateral symmetry
- Evans, P. 1987. The Natural History of Whales and Dolphins. New York, New York: Facts on File Publications.
- Tinker, W. 1988. Whales of the World. New York, New York: E. J. Brill.
- Walker, E. 1975. Mammals of the World. Baltimore, MD: The Johns Hopkins University Press.
- UNESCO-IOC Register of Marine Organisms
Based on stomach contents and locations where Tasmacetus shepherdi have washed ashore, this species is likely benthic and inhabits temperate waters of the southern hemisphere (Evans 1987, Tinker 1988).
Aquatic Biomes: benthic
Habitat and Ecology
Shepherd’s beaked whales are known to feed on several species of fish (primarily eelpouts), as well as squid and crabs, possibly near the bottom in deep waters. This seems somewhat unusual, as most beaked whales appear to feed almost exclusively on cephalopods.
These whales eat squid and various fishes. Many of these fishes are benthic, suggesting that Tasmacetus shepherdi feeds at or near the sea floor (Tinker 1988).
Animal Foods: fish; mollusks
Primary Diet: carnivore (Molluscivore )
Life History and Behavior
Perception Channels: tactile ; chemical
Nothing is currently known about the reproduction of this species.
Key Reproductive Features: gonochoric/gonochoristic/dioecious (sexes separate); sexual
The IUCN lists Tasmacetus shepherdi under the "insufficiently known" category (Simmonds and Hutchinson 1996).
US Federal List: no special status
CITES: no special status
IUCN Red List of Threatened Species: data deficient
IUCN Red List Assessment
Red List Category
Red List Criteria
- 1996Data Deficient
- 1994Insufficiently Known(Groombridge 1994)
Evidence from stranded individuals of Tasmacetus shepherdi indicated that they had swallowed discarded plastic items (reference?), which may eventually lead to death (e.g. Scott et al. 2001).
This species, like other beaked whales, is likely to be vulnerable to loud anthropogenic sounds, such as those generated by navy sonar and seismic exploration (Cox et al. 2006).
Predicted impacts of global climate change on the marine environment may affect this species of whale, although the nature of impacts is unclear (Learmonth et al. 2006).
Relevance to Humans and Ecosystems
Tasmacetus shepherdi is not economically important.
IUCN Red List Category
- IUCN (2008) Cetacean update of the 2008 IUCN Red List of Threatened Species.
Shepherd's beaked whale
Shepherd's Beaked Whale (Tasmacetus shepherdi) also commonly called the Tasman Beaked Whale or simply the Tasman Whale is a cetacean of the family Ziphidae. The whale has hardly been studied at all. No certain identification has been made at sea and only 28 specimens have been recorded stranded.
Shepherd's Beaked Whale had a long beak which narrows to a pointed tip and a bluff melon. It is the only beaked whale with a full set of functional teeth. The body is about seven metres long and the dorsal fin is located about two-thirds the way along the back. The fin is falcate. The back is coloured dark brown to black with lighter patches running diagonally on the sides with a light underside.
Population and distribution
No population estimates exist for Shepherd's Beaked Whale. As of 2003, 20 stranded specimens had been collected from New Zealand, 3 from Argentina, 2 from the Juan Fernández, 1 from Australia and 1 from the Sandwich Islands. There have been two reports of live sightings - one in New Zealand and one from the Seychelles. On 5 March 2004 a twentieth-eighth stranding was found by a surfer on the coast of Taranaki in the north of Waitara, New Zealand (close to the site of the first stranding in 1933). The specimen was removed for autopsy by the Department of Conservation.
No information is available about group sizes, diving pattern or migatory patterns. The paucity of information may be due to the species having a very shy manner, or its rarity, or both.
There are no reports of this species being hunted or killed accidentally by humans.
- ^ Taylor, B.L., Baird, R., Barlow, J., Dawson, S.M., Ford, J., Mead, J.G., Notarbartolo di Sciara, G., Wade, P. & Pitman, R.L. (2008). Tasmacetus shepherdi. In: IUCN 2008. IUCN Red List of Threatened Species. Downloaded on 24 March 2009. Database entry includes a brief justification of why this species is of data deficient.
- Shepherd's Beaked Whale in the Encyclopedia of Marine Mammals Thomas A. Jefferson, 1998. ISBN 0-12-551340-2
- National Audubon Society Guide to Marine Mammals of the World Reeves et al., 2002. ISBN 0-375-41141-0.
- Whales, Dolphins and Porpoises Carwardine, 1995. ISBN 0-7513-2781-6
- News report on 28th recording stranding
- Laughlin, C. 1996. Probable Sighting of Tasmacetus Shepherdi in the South Atlantic. Marine Mammal Science, 12(3): 496-497.