In addition, proponents and land managers should refer to the Recovery Plan (where available) or the Conservation Advice (where available) for recovery, mitigation and conservation information.
|EPBC Act Listing Status||Cetacean|
|Adopted/Made Recovery Plans|
|Policy Statements and Guidelines||
Industry Guidelines on the Interaction between offshore seismic exploration and whales (Department of the Environment and Water Resources (DEW), 2007h) [Admin Guideline].
Australian National Guidelines for Whale and Dolphin Watching (Department of the Environment and Heritage, 2005e) [Information Sheet].
|Scientific name||Mesoplodon hectori |
This is an indicative distribution map of the present distribution of the species based on best available knowledge. See map caveat for more information.
Scientific name: Mesoplodon hectori
Common name: Hector's Beaked Whale
Hector's Beaked Whale was first described in 1971 by the British biologist, John Gray, and named after the curator of the Colonial Museum in Wellington, New Zealand, where the type specimen originated (Leatherwood & Reeves 1983). No subspecies are currently recognised (Rice 1998). Specimens from southern California, hitherto classified as M. hectori, have been described recently as a new species, M. perrini (Dalebout et al. 2002).
Hector's Beaked Whale is dark grey to brown, with pale grey undersides extending forward to a white lower jaw. A pair of moderately small, flattened triangular teeth that erupt near the tip of the lower jaw in males make the sexes distinctive (Jefferson et al. 1993). Males also have white undersides to the flukes and there can be a white area in the vicinity of the umbilicus (navel) (Leatherwood & Reeves 1983). The dorsal fin is small and round-tipped, while the short flippers have parallel edges and the tail flukes are broad and almost straight edged (Shirihai 2002). Scratches and scars are common on the flanks, particularly in males (Martin 1990).
Almost nothing is known of the natural history of Hector's Beaked Whale. This overview is based on the few data available from New Zealand, South Africa and Australia. Hector's Beaked Whales reach physical maturity at a length of about 4.0 m. Female Hector's Beaked Whales have been measured up to 4.43 m and males up to 4.30 m, suggesting that the estimated maximum size would probably be around 4.5 m, with a maximum weight of about 800 kg (Leatherwood & Reeves 1983).
Hector's Beaked Whales usually occur singly, but groups of two individuals have been observed (Shirihai 2002).
Only a few Hector's Beaked Whales have been recorded in Australia, including one from South Australia and two from Tasmania (Ross 2006). An additional record was identified in Western Australia, based on a DNA sample collected from a free-swimming whale (Gales et al. 2002).
The paucity of sightings for Hector's Beaked Whales precludes accurate calculation of the current extent of occurrence or area of occupancy. However, the species is considered to occur in one location in Australian oceanic sub-Antarctic and temperate waters, without any severe fragmentation.
The area of occupancy of Hector's Beaked Whales cannot be calculated due to the paucity of records in Australia. However, it is likely to be greater than 2000 km² (Peddemors & Harcourt 2006, pers. comm.). Future expansion of high-seas pelagic gillnet fisheries could result in increased incidental catches, potentially depleting local waters and leading to a decrease in area of occupancy.
Hector's Beaked Whales are considered to occur in one location as deep water is not to be a barrier to dispersal.
No distribution fragmentation is anticipated for Hector's Beaked Whales in Australian oceanic sub-Antarctic and temperate waters.
Hector's Beaked Whale occurs south of the Tropic of Capricorn and is distributed circumglobally between about 35° S to 55° S (Ross 2006; Shirihai 2002). Hector's Beaked Whales are primarily known from a few strandings in Argentina, Chile, the Falkland Islands, South Africa, New Zealand and in Australia (Ross 2006).
No estimates of population size exist for Hector's Beaked Whale and, with the exception of one whale taken in the 1800s in New Zealand (Jefferson et al. 1993), no records of human exploitation exist. According to Pitman (2002) so few Mesoplodonts (beaked whales) have been reliably identified at sea that it is impossible to accurately determine the population status of any species. Based on stranding and sighting data, Hector's Beaked Whale may be rare (Pitman 2002).
It is unlikely that Australian Hector's Beaked Whales are a distinct population, as no subspecies are currently recognized (Dalebout et al. 2002; Rice 1998). As Hector's Beaked Whale is a deep water species primarily living off the continental shelf, incidental bycatch of animals in neighbouring countries and/or international waters may affect the Australian population.
World-wide, Hector's Beaked Whale is not well surveyed. Their distribution is primarily assumed from incidental sightings, plus beach-cast animals, for all areas.
No population size is known, although Hector's Beaked Whales are not considered abundant as sightings and strandings are rare.
All cetaceans are protected within the Australian Whale Sanctuary under the EPBC Act 1999. The Sanctuary includes all Commonwealth waters from the three nautical mile state waters limit out to the boundary of the EEZ (200 nm and further in some places). Hector's Beaked Whales are also subject to International Whaling Commission (IWC) regulations and protected within the Indian Ocean Sanctuary and Southern Ocean Sanctuary.
Hector's Beaked Whales are thought to prefer deep oceanic waters of cool temperate (between 1020 °C) to sub-antarctic (between 18 °C) regions (Pittman 2002; Ross 2006), rarely venturing into continental seas (further discussion in Gales et al. 2002). No information on habitat is available, although these whales are presumed to feed at depth on mid- and deep-water squid (Macleod et al. 2003; Pitman 2002). Shipboard surveys of beaked whales (Mesoplodon spp. and Ziphius cavirostris) from 19911998 along the shelf edge and Gulf Stream waters off the northeast United States showed that these species frequent shelf-edge habitats (Waring et al. 2001). Beaked whales were present mostly along the colder shelf edge and associated significantly with canyon habitats (Waring et al. 2001). However, a more recent survey of the same area found that this previous proposed definition of beaked whale habitat may be too narrow, suggesting that beaked whales may be found from the continental slope to the abyssal plain, in waters ranging from well-mixed to highly stratified (Ferguson et al. 2006). It is likely that such habitats are utilised by Hector's Beaked Whales along much of Australia's extensive coastline (Ross 2006).
As for many species of beaked whale, Hector's Beaked Whale may also be found close to undersea features such as submarine escarpments and sea mounts where prey are believed to aggregate (Balcomb 1989). In the eastern tropical Pacific, beaked whales were sighted an average of 1000 km offshore, with a range of approximately 403750 km. The mean water depth of Mesoplodon beaked whale sightings in this region was just over 3.5 km, with a maximum depth of approximately 5.75 km (Ferguson et al. 2006).
Sexual maturity in Hector's Beaked Whale occurs at approximately 4.0 m in length (Ross 2006). Longevity data for Mesoplodonts are virtually non-existent, although they may be quite long lived (Pitman 2002). The maximum recorded age for the related Baird's Beaked Whale (Berardius bairdii) is 84 years, and for all other beaked whales recorded age is between 27 and 39 (Mead 1984 cited in MacLeod & D'Amico 2006). Natural causes of mortality are poorly understood, but are thought to include predation, disease and effects associated with 'old age' (MacLeod & D'Amico 2006).
Almost nothing is known regarding reproduction in Hector's Beaked Whales. Gestation period, calving interval, and calving areas are all unknown (Bannister et al. 1996; Ross 2006). Length at birth is about 1.8 m, but length at weaning is not known (Ross 2006).
There are no known reproductive behaviours that may make Hector's Beaked Whale vulnerable to a threatening process, although a suspected calving interval of at least three to four years leads to a slow reproductive capacity.
The diet of Hector's Beaked Whale is presumed to be mainly mid- and deep-water squid and some fish. The reference to Octopoteuthis deletron beaks found in stomachs of Hector's Beaked Whale (Bannister et al. 1996) has been retracted, as the whale involved has been re-classified as M. perrini (Dalebout et al. 2002).
Hector's Beaked Whale is presumed to actively pursue prey, but the mode of capture is not known. It is possibly capable of deep dives. Only adult males have functional teeth, consisting of one pair near the tip of the lower jaw, but these appear to be used more as weapons during agonistic encounters than in capturing prey (Ross 2006). Lacking functional gripping teeth, prey may be seized and disabled using the hard edges of the mandibles and the rostral palate (Bannister et al. 1996). The pair of V-shaped throat grooves typical of this family may enable distension of the throat, creating a sucking pressure allowing larger prey to be swallowed whole (Baker 1990; Pitman 2002).
In the Southern Hemisphere, the tooth positioning in Hector's Beaked Whales can easily lead to confusion with True's Beaked Whale, Longman's Beaked Whale or Arnoux's Beaked Whale. The larger body size and cone-shaped rather than flattened teeth are likely to help distinguish Cuvier's Beaked Whale from Hector's Beaked Whale (Leatherwood & Reeves 1983).
Beaked whales are notoriously difficult to identify at sea due to their propensity to spend little time at the surface, breathing only a few times before submerging for extensive periods. Whilst at the surface they are slow moving and inconspicuous, particularly as they don't 'blow' (Jefferson et al. 1993; Pitman 2002).
Cetacean surveys are constrained by several important factors including weather (e.g. sea state and light conditions), area to be covered, aim of the survey (abundance estimate versus ecological studies), the activities of the animals themselves (e.g. travelling, resting, surface versus deep feeding), and the type of craft used for the survey.
Surveys for oceanic cetaceans such as beaked whales have primarily been boat-based transects. There are almost no dedicated cetacean surveys conducted in temperate Australian waters, but surveys conducted en route to the Antarctic have covered substantial portions of potential range of Hector's Beaked Whales. Unfortunately, much of this range is in areas experiencing few calm days, leading to difficulty in sighting beaked whales. During non-dedicated surveys, a minimum requirement is to record all cetacean sightings encountered with corresponding GPS position, environmental data (sea conditions and habitat) and behavioural observations. From fishing vessels, all incidentally caught animals should be recorded with corresponding GPS position, plus attempts should be made to obtain basic biological information from dead animals.
Although there has never been a directed fishery, some Mesoplodonts are occasionally taken by opportunistic whalers (Pitman 2002). No other past threats to Hector's Beaked Whale are known.
Incidental entanglement in gillnets is a more likely potential threat (Reeves et al. 2003). Investigations of incidental captures in the pelagic drift gillnet fishery off the north-east United States coast, indicated that 46 fishery related mortalities of Mesoplodonts occurred between 1989 and 1998, 24 of which were Sowerby's Beaked Whales (M. bidens), four were True's Beaked Whales (M. mirus) and 17 were unidentified beaked whales (Waring et al. 2001). This highlights that entanglement in drift nets and other nets set, lost or discarded in international waters, should be considered as a current and potentially increasing threat to Hector's Beaked Whales (Bannister et al. 1996; Reeves et al. 2003; Ross 2006).
Recently, there have been a number of studies investigating the impacts of anthropogenic noise on beaked whales, particularly activities that transmit sounds into the water column. These studies have, in part, been driven by mass strandings of beaked whales coinciding temporally and spatially with naval manoeuvres (MacLeod & D'Amico 2006). For example, necropsies (autopsies) of stranded Blainville and Cuvier's beaked whales following low frequency acoustic sonar tests have revealed tissue trauma associated with an acoustic or impulse injury that caused the animals to strand (Frantzis 1998). It has been noted that beaked whales with group sizes of less than 20 (including the Mesoplodon spp.), and particularly groups composed primarily of immature, juvenile or cow-calf pairs, may be more susceptible to strandings associated with anthropogenic noise, although it is not known why this might be the case. Anthropogenic sounds may disrupt or interfere with the sounds produced by beaked whales, including disruption of navigation, and/or interfere with social communication. While data is limited, where there is data beaked whales appear to use relatively high frequency echolocation (up to 120 kHz or more) and non-echolocation sounds in the region of 116 kHz (MacLeod & D'Amico 2006).
Although little is known about reproduction in beaked whales, it is likely that Hector's Beaked Whales have a low reproductive rate, producing one offspring every three to four years. This means that population recovery is a slow process.
Bannister and colleagues (1996) and Ross (2006) recommended the following actions be taken to better understand the threats to Hector's Beaked Whale:
- Determine the distribution and monitor abundance of Hector's Beaked Whale in Australian waters to assess the possible impact of threats, particularly the effect of direct and indirect fishing activities. This should be done via a sighting program to monitor numbers, particularly in southern waters.
- Obtain information on Hector's Beaked Whale diet to determine their trophic level and assess any possible impact of the fishing industry on beaked whale food resources.
- Obtain basic biological information (including confirmation of colouration variations, diet, pollutant levels and genetic samples) from incidentally-caught and stranded Hector's Beaked Whale specimens, and ensure specimens are made available to appropriate scientific museums to enable collection of life history data and tissue samples for genetic analysis.
Projects currently initiated to address these threats include a requirement to report all incidental catches made within the Australian EEZ (Bannister et al. 1996). Disentanglement workshops have also been initiated, and may be particularly relevant for offshore fishers.
The Action Plan for Australian Cetaceans (Bannister et al. 1996) and the Review of the Conservation Status of Australia's Smaller Whales and Dolphins (Ross 2006) provide brief biological overviews and management recommendations of this species. In addition, Industry Guidelines on the Interaction between offshore seismic exploration and whales (EA 2001k), and Australian National Guidelines for Whale and Dolphin Watching (DEH 2005c) have been published.
No threats data available.
Baker, A. (1990). Whales and Dolphins of Australia and New Zealand: An Identification Guide. Page(s) 133 pp. Wellington, New Zealand: Victoria University Press.
Balcomb, K.C. (1989). Baird's Beaked Whale Berardius bairdii Stejnegeri, 1833: Arnoux's Beaked Whale Berardius arnuxii Duvernoy, 1851. In: Ridgway, S.H. & R. Harrison, eds. Handbook of Marine Mammals Vol. 4: River Dolphins and the Larger Toothed Whales. Page(s) 261-288.
Bannister, J.L., C.M. Kemper & R.M. Warneke (1996). The Action Plan for Australian Cetaceans. [Online]. Canberra: Australian Nature Conservation Agency. Available from: http://www.environment.gov.au/coasts/publications/cetaceans-action-plan/pubs/whaleplan.pdf.
Dalebout, M.L., J.G. Mead, C.S. Baker, A.N. Baker & A.L. van Helden (2002). A new species of beaked whale Mesoplodon perrini sp. n. (Cetacea: Ziphiidae) discovered through phylogenetic analyses of mitochondrial DNA sequences. Marine Mammal Science. 18(3):577-609.
Department of the Environment and Heritage (2005e). Australian National Guidelines for Whale and Dolphin Watching. [Online]. Available from: http://www.environment.gov.au/coasts/publications/whale-watching-guidelines-2005.html.
Department of the Environment and Water Resources (DEW) (2007h). Industry Guidelines on the Interaction between offshore seismic exploration and whales. [Online]. Available from: http://www.environment.gov.au/epbc/publications/seismic.html.
Ferguson, M.C., J. Barlow, B. Reilly, S.B. & T. Gerrodette (2006). Predicting Cuvier's (Ziphius cavirostris) and Mesoplodon beaked whale population density from habitat characteristics in the Eastern Tropical Pacific Ocean. Journal of Cetacean Research and Management. 7(3):287-299.
Frantzis, A. (1998). Does acoustic testing strand whales?. Nature. 392:29.
Gales, N.J., M.L. Dalebout & J.L. Bannister (2002). Genetic identification and biological observation of two free-swimming beaked whales: Hector's Beaked Whale (Mesoplodon hectori, Gray, 1871), and Gray's Beaked Whale (Mesoplodon grayi, Von Haast, 1876). Marine Mammal Science. 18:544-555.
Jefferson, T.A., S. Leatherwood & M.A. Webber (1993). FAO species identification guide. Marine Mammals of the World. [Online]. Rome: United Nations Environment Programme, Food and Agricultural Organization. Available from: ftp://ftp.fao.org/docrep/fao/009/t0725e/t0725e00.pdf. [Accessed: 15-Aug-2007].
Leatherwood, S. & R.R. Reeves (1983). The Sierra Club Handbook of Whales and Dolphins. San Francisco: Sierra Club Books.
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MacLeod, C.D., M.B. Santos & G.J. Pierce (2003). Review of data on diets of beaked whales: Evidence of niche separation and geographic segregation. Journal of the Marine Biological Association of the United Kingdom. 83:651-665.
Martin, A.R. (1990). Whales and Dolphins. London, UK: Salamander Books Ltd.
Pitman, R.L. (2002). Mesoplodont Whales Mesoplodon spp. In: Perrin, W.F., Wursig, B. & Thewissen, J.G.M., eds. Encyclopedia of Marine Mammals. Page(s) 738-742. London, Academic Press.
Reeves, R.R., B.D. Smith, E.A.Crespo, & G. Notarbartolo di Sciara, eds. (2003). Dolphins, Whales and Porpoises: 2002-2010 Conservation Action Plan for the World's Cetaceans. Switzerland and Cambridge: IUCN/SSC Cetacean Specialist Group. IUCN, Gland.
Rice, D.W. (1998). Marine mammals of the world. Systematics and distribution. Special publication number 4. Kansas: Society for Marine Mammalogy.
Ross, G.J.B. (2006). Review of the Conservation Status of Australia's Smaller Whales and Dolphins. Page(s) 124. [Online]. Report to the Australian Department of the Environment and Heritage, Canberra. Available from: http://www.environment.gov.au/coasts/publications/pubs/conservation-smaller-whales-dolphins.pdf.
Shirihai, H. (2002). The Complete Guide to Antarctic Wildlife. Princeton & Oxford: Princeton University Press.
Waring, G.T., J.M. Quintal & S.L. Swartz (2001). U.S. Atlantic and Gulf of Mexico marine mammal stock assessments - 2001. NOAA Technical Memorandum. NMFS-NE168.
This database is designed to provide statutory, biological and ecological information on species and ecological communities, migratory species, marine species, and species and species products subject to international trade and commercial use protected under the Environment Protection and Biodiversity Conservation Act 1999 (the EPBC Act). It has been compiled from a range of sources including listing advice, recovery plans, published literature and individual experts. While reasonable efforts have been made to ensure the accuracy of the information, no guarantee is given, nor responsibility taken, by the Commonwealth for its accuracy, currency or completeness. The Commonwealth does not accept any responsibility for any loss or damage that may be occasioned directly or indirectly through the use of, or reliance on, the information contained in this database. The information contained in this database does not necessarily represent the views of the Commonwealth. This database is not intended to be a complete source of information on the matters it deals with. Individuals and organisations should consider all the available information, including that available from other sources, in deciding whether there is a need to make a referral or apply for a permit or exemption under the EPBC Act.
Citation: Department of the Environment (2013). Mesoplodon hectori in Species Profile and Threats Database, Department of the Environment, Canberra. Available from: http://www.environment.gov.au/sprat. Accessed Tue, 10 Dec 2013 12:31:00 +1100.