Species Profile and Threats Database

For information to assist proponents in referral, environmental assessments and compliance issues, refer to the Policy Statements and Guidelines (where available), the Conservation Advice (where available) or the Listing Advice (where available).
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
Other EPBC Act Plans Threat abatement plan for the impacts of marine debris on vertebrate marine life (Department of the Environment, Water, Heritage and the Arts (DEWHA), 2009t) [Threat Abatement Plan].
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].
Information Sheets Australian National Guidelines for Whale and Dolphin Watching (Department of the Environment and Heritage, 2005e) [Information Sheet].
Non-statutory Listing Status
IUCN: Listed as Least Concern (Global Status: IUCN Red List of Threatened Species: 2013.1 list)
Scientific name Peponocephala electra [47]
Family Delphinidae:Cetacea:Mammalia:Chordata:Animalia
Species author (Gray,1846)
Infraspecies author  
Distribution map Species Distribution Map

This is an indicative distribution map of the present distribution of the species based on best available knowledge. See map caveat for more information.

Illustrations Google Images

Scientific name: Peponocephala electra

Common name: Melon-headed Whale

Originally described as Lagenorhynchus electra by Gray in 1846, the Melon-headed Whale was recently placed in the monospecific genus Peponocephala. There does not appear to be any current taxonomic confusion surrounding the species, and no subspecies are recognised (Jefferson & Barros 1997). The recognition of the new species status was aided by Australian material (Bannister et al. 1996).

The Melon-headed Whale is mostly dark grey, with a faint darker grey cape, narrowing at the head. A faint light band extends from the blowhole to the apex of the melon. A distinct dark eye patch, broadening as it extends from the eye to the melon, is characteristic for Melon-headed Whales. The lips are often white, and white or light grey areas are common in the throat region and the venter. At sea, the Melon-headed Whale is difficult to distinguish from the Pygmy Killer Whale (Feresa attenuata), but has a more pointed head and sharply pointed pectoral fins. Melon-headed Whales also have twice as many teeth as Pygmy Killer Whales. The upper jaws of Melon-headed Whales have 20–25 sharp pointed teeth, while the lower jaws have 22–24. Adult males are slightly larger than females (2.70 m and 2.60 m respectively) and may reach 228 kg in weight (Perryman 2002).

Melon-headed Whales occur in large groups, ranging from herds of 150–1500 animals to groups of less than 40. They are fast swimmers, breaking the water at a shallow angle, and jumping clear of the water. They may spy-hop and swim with dolphins (Fraser's Dolphin (Lagenodelphis hosei), Pantropical Spotted Dolphin (Stenella attenuata) and Spinner Dolphins (Stenella longirostris)). Melon-headed Whales have been reported herding other Melon-headed Whales and possibly attacking dolphins (Bryden et al. 1977; Dawbin et al. 1970; Leatherwood & Reeves 1983; Perryman et al. 1994).

In Australian waters, Melon-headed Whales have been recorded from Western Australia, Queensland (mass stranding of 53 animals), NSW (mass strandings of 150–250 animals at Crowdy Head, and seven animals at Point Plomer) and the Northern Territory (mass stranding of 40 animals at Elcho Island) (Chatto & Warneke 2000; Ross 2006). Other single strandings of Melon-headed Whales have been recorded in these states. It is therefore probable that Melon-headed Whales occur across the entire northern half of Australia (Bryden et al. 1977a), north of 35° S.

Offshore waters surrounding Browse Island support a larger number of cetacean species than any other area on the Western Australian coast, including large pods of oceanic dolphins, Melon-headed Whales, Pygmy Killer Whales (Feresa attenuata), False Killer Whales (Pseudorca crassidens), Minke Whales (Balaenoptera acutorostrata) and Pilot Whales (Globicephala spp.) (Jenner & Jenner 2007 cited in DEWHA 2008b).

The current extent of occurrence for Melon-headed Whales is estimated to be greater than 20 000 km² (based on the Australian Economic Exclusion Zone (EEZ) (200 nm and north of 35°S)) (V. Peddemors & R. Harcourt 2006, pers. comm.). Increasing ocean temperatures predicted by climate change scenarios could potentially increase the extent of occurrence of the Melon-headed Whale, with warmer water extending southwards.

The area of occupancy of Melon-headed Whales cannot be calculated due to the sparsity of records for Australia. However, it is likely to be greater than 2000 km² (V. Peddemors & R. Harcourt 2006, pers. comm.). Future expansion of high seas pelagic fisheries may result in increased interactions with Melon-headed Whales, including incidental catches and injury, potentially depleting local waters and leading to a decrease in area of occupancy.

Melon-Headed Whales are currently considered to occur in one location as deep water is not a barrier to movement in this species and there are no known unsurpassable fixed pelagic boundaries in the Australian region.

Melon-headed Whales are pantropical, occurring in all deep oceanic waters between 35° N and 35° S (DEWHA 2008b). They range north to the Gulf of Mexico, Senegal, Arabian Sea, Bay of Bengal, South China Sea, Taiwan, southern Honshu, Hawaiian Islands, and Baja California Sur. Melon-headed Whales range south to Espiritu Santo in Brazil, Timor Sea, northern NSW, and Peru (Rice 1998). Mignucci-Giannoni and colleagues (1998) also report the species from the Caribbean sea. Melon-headed Whale specimens from southern Japan, Cornwall in England, the Cape Province in South Africa, and Maryland, USA probably represent the extremes of the normal distribution for this species and may have come from populations in adjacent warm currents (Perryman et al. 1994; Rice 1998).

The Melon-headed Whale is a poorly known species. The only abundance estimates are for the eastern tropical Pacific, where it has been estimated that there are approximately 45 000 (Wade & Gerrodette 1993), the northern Gulf of Mexico with approximately 4000 individuals (Waring et al. 2001) and the eastern Sulu Sea with an estimate of 1200 individuals (Dolar et al. 1994). No global estimate of population size is available. However, no particular conservation problem has been identified (Reeves et al. 2003).

It is unlikely that Australian Melon-headed Whales are a distinct population, as no subspecies are currently recognised. Melon-headed Whales are found in all deep oceanic waters at tropical and subtropical latitudes, thus mortalities in neighbouring countries and/or international waters may affect the Australian population.

Melon-headed Whales are not known to be migratory but seasonal movements may be made, possibly related to food supply.

Melon-headed Whales are not well surveyed within Australian waters. Their distribution is primarily assumed from incidental sightings, plus beach-cast animals, for all areas. However, this assumption is believed to result in reliable distributional information for this species.

No population estimates are available for Melon-headed Whales in Australian waters. However, they may be more common in Australian waters than records suggest (Perryman et al. 1994). It is likely that the total number of mature animals within Australian waters is more than 10 000, considering the large group sizes recorded off the coast (Bryden et al. 1977).

All cetaceans are protected within The Australian Whale Sanctuary under the EPBC Act. The Sanctuary includes all Commonwealth waters from the 3 nm state waters limit out to the boundary of the EEZ (i.e. out to 200 nm and further in some places). Melon-headed Whales are also subject to International Whaling Commission regulations, and protected within the Indian Ocean Sanctuary and Southern Ocean Sanctuary.

Melon-headed Whales inhabit mainly equatorial waters that are warmer than 25 °C. Most sightings of Melon-headed Whales are from the continental shelf seaward, and around oceanic islands (Culik 2000d). In the eastern tropical Pacific, the distribution of reported sightings suggests that the oceanic habitat of this species is primarily in upwelling modified and equatorial waters (Perryman et al. 1994; Ross 2006).

Life history data for Melon-headed Whales are extremely limited. Reproductive information is based on data from a mass stranding in Japan (Jefferson & Barros 1997). Males reach sexual maturity at 16.5 years and 2.44 m in length, while females are sexually mature at about 11.5 years and 2.35 m. Physical maturity is attained by 13.5 years in both sexes. The maximum age for Melon-headed Whales is unknown, but they may live for over 30 years and attain lengths of approximately 2.75 m (Perrin ² Reilly 1984). There is some indication that females live longer than males (Jefferson & Barros 1997). The natural mortality rate is unknown but regular mass strandings reported from around the world (Jefferson & Barros 1997) indicate that natural mortalities may be high. Necropsies of these mass strandings report high parasite loads (Jefferson & Barros 1997).

Very little data exists for any breeding parameter of Melon-headed Whales (Jefferson & Barros 1997). There is some evidence to indicate a calving peak in July and August, but this is inconclusive (Jefferson et al. 1993). In the Southern Hemisphere, calving may peak between August and December (Klima 1994). Calves are born at around 1 m in length and gestation may last for approximately one year (as in most smaller delphinids) (Bryden et al. 1977; Jefferson & Barros 1997). No calving areas are known in Australian waters.

There are no known reproductive behaviours that may make Melon-headed Whales particularly vulnerable to a specific threatening process. However a probable calving interval of two to three years may lead to a slow reproductive capacity.

Melon-headed whales are known to feed on pelagic squid and fishes, and occasionally crustaceans (Jefferson & Barros 1997). Most of the fishes eaten by Melon-headed Whales consist of mesopelagic species, found in waters up to 1500 m deep, suggesting that feeding takes place deep in the water column (Jefferson & Barros 1997).

Few observations of foraging Melon-headed Whales have been made. They are known to regularly constitute mixed groups with other species of cetaceans, including Fraser's Dolphins, Rough-toothed Dolphins (Steno bradanensis) and Bottlenose Dolphins (Tursiops aduncus) (Jefferson & Barros 1997). By driving fish towards the water's surface, Melon-headed Whales appear to provide feeding opportunities for some seabirds (Jefferson & Barros 1997).

There is no information on the movement patterns of Melon-headed Whales in Australian waters. However, elsewhere they appear to be present in their ranges year-round (Jefferson & Barros 1997).

Distinctiveness and detectability
At sea, Melon-headed Whales are often difficult to distinguish from Pygmy Killer Whales. Major differences are that the Melon-headed Whale has a dark triangular 'mask' over the face with the apex pointing posteriorly, a dark cape below the dorsal fin, and an acute flipper apex (Peddemors & Ross 1988). Large herds are characteristic of Melon-headed Whales and, at a distance, this often provides a clue to this species. They often move quickly, leaping clear of the water and showing the characteristic pointed flipper.

Recommended methods
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. traveling, resting, surface versus deep feeding), and the type of craft used for the survey.

Surveys for oceanic cetaceans, such as Melon-headed Whales, have primarily been boat-based transects. There are almost no dedicated cetacean surveys conducted in continental Australian waters. 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 (V. Peddemors 2006, pers. comm.).

No past threats have been identified as affecting Melon-headed Whales. Current threats to Melon-headed Whales possibly include: illegal and incidental catches in northern Australian waters; incidental catches in gillnets in Sri Lanka; and small numbers taken in purse seine nets in the eastern tropical Pacific. Melon-headed Whales have been captured in low numbers in small cetacean fisheries in several places, including Japan, Indonesia and Sri Lanka. Potential threats to Melon-Headed Whales include entanglement in driftnets set outside the Australian EEZ and in lost or discarded netting (Reyes 1991); pollution (including increasing amounts of plastic debris at sea, oil spills and dumping of industrial wastes into waterways and the sea) leading to bio-accumulation of toxic substances in body tissues (Bannister et al. 1996; Kemper et al. 1994), and the recent discovery of the disease morbillivirus in the carcass of a Melon-headed Whale stranded at Fraser Island, Queensland, in July 2006 (Long 2006).

Pollution, ship strikes and anthropogenic marine noise have been suggested as contributing to cetacean strandings in the Australia's North Marine Region, where Melon-headed whale strandings are known to have occurred (DEWHA 2008).

General threats to cetaceans that may affect Melon-headed Whales in Australia's South-west Marine Region include commercial fishing, oil and gas exploration and development, Department of Defence activities, shipping, human maritime and shore sourced pollution, recreational boating and whale/dolphin watching activities (DEWHA 2008a).
Although little is known about reproduction in Australian Melon-headed Whales, it is likely that they have a low reproductive rate, producing one offspring every two to three years. This suggests that population recovery is a slow process.

Bannister and colleagues (1996) and Ross (2006) recommend the following actions be taken to better understand the threats to Melon-headed Whales:

  • Determine the distribution, and monitor abundance, of Melon-headed Whales 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 subtropical and tropical waters. There should be consideration to pool existing sightings and strandings data to locate possible concentration areas.
  • Obtain information on Melon-headed Whale diet to determine their trophic level and assess any possible impact of the fishing industry on Odontocete food resources.
  • Obtain basic biological information (including diet, pollutant levels and tissue samples for genetic analysis) from incidentally-caught, and stranded, Melon-headed Whale specimens.

Current projects initiated to address these threats include a requirement to report all incidental catches made within the Australian EEZ. Disentanglement workshops have also been initiated, and may be particularly relevant for offshore fishers.

No threats data available.

Bannister, J.L., C.M. Kemper & R.M. Warneke (1996). The Action Plan for Australian Cetaceans. [Online]. Canberra: Australian Nature Conservation Agency. Available from:

Bryden, M.M., R.J. Harrison and R.J. Lear (1977). Some aspects of the biology of Peponocephala electra (Cetacea: Delphinidae) I. General and reproduction biology. Australian Journal of Marine and Freshwater Research. 28:705-715.

Bryden, M.M., W.H. Dawbin, G.E. Heinsohn, & D.H. Brown (1977a). Melon-headed whale, Peponocephala electra, on the east coast of Australia. Journal of Mammalogy. 58:180-187.

Chatto R. & R.M. Warneke (2000). Records of cetacean strandings in the Northern Territory of Australia. The Beagle, Records of the Museums and Art Galleries of the Northern Territory. 16:163-175.

Culik, B. (2000d). Peponocephala electra. In: Review on Small Cetaceans: Distribution, Behaviour, Migration and Threats. [Online]. Compiled for the Convention on Migratory species (CMS).

Dawbin, W.H., B.A. Noble & F.C. Fraser (1970). Observations on the Electra Dolphin, Peponocephala electra. Bulletin of the British Museum (Natural History), Zoology. 20:175-201.

Department of the Environment and Heritage (2005e). Australian National Guidelines for Whale and Dolphin Watching. [Online]. Available from:

Department of the Environment and Water Resources (DEW) (2007a). Draft East Marine Bioregional Plan: Bioregional Profile: A Description of the Ecosystems, Conservation Values and Uses of the East Marine Region.

Department of the Environment and Water Resources (DEW) (2007h). Industry Guidelines on the Interaction between offshore seismic exploration and whales. [Online]. Available from:

Department of the Environment, Water, Heritage and the Arts (DEWHA) (2008). The North Marine Bioregional Plan: Bioregional Profile: A Description of the Ecosystems, Conservation Values and Uses of the North Marine Region. [Online]. Canberra: DEWHA. Available from:

Department of the Environment, Water, Heritage and the Arts (DEWHA) (2008a). The South-West Marine Bioregional Plan: Bioregional Profile: A Description of the Ecosystems, Conservation Values and Uses of the South-West Marine Region. [Online]. Canberra: DEWHA. Available from:

Department of the Environment, Water, Heritage and the Arts (DEWHA) (2008b). North-West Marine Bioregional Plan: Bioregional Profile: A Description of the Ecosystems, Conservation Values and Uses of the North-West Marine Region. [Online]. Canberra: DEWHA. Available from:

Department of the Environment, Water, Heritage and the Arts (DEWHA) (2009t). Threat abatement plan for the impacts of marine debris on vertebrate marine life. [Online]. Available from:

Dolar, M.L.L., S.J. Leatherwood, C.J. Wood, M.N.R. Alava, & C.L. Hill (1994). Directed fisheries for cetaceans in the Phillipines. Rep. Int. Whal. Rep. Int. Whal. Comm. 44:439-449.

Jefferson, T.A. & N.B. Barros (1997). Peponocephala electra.. Mammalian Species. 553:1-6.

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: [Accessed: 15-Aug-2007].

Kemper, C.M., P. Gibbs, D. Obendorf, S. Marvanek & C. Lenghaus (1994). A review of heavy metal and organochlorine levels in marine mammals in Australia. Science of the Total Environment. 154:129-139.

Klima, M. (1994). Niethammer J. & F. Krapp, eds. Peponocephala electra - Melonenkopf oder Breitschnabeldelphin. 6:482 - 488. Wiesbaden, Germany: Aula-Verlag.

Leatherwood, S. & R.R. Reeves (1983). The Sierra Club Handbook of Whales and Dolphins. San Francisco: Sierra Club Books.

Long, T. (2006). Quoted in: 'Hopes post-mortem will shed light on whale's death'. [Online]. Available from: [Accessed: 14-Aug-2006].

Mignucci-Giannoni, A.A., M.A. Rodriguez-Lopez, J.J. Perez-Zayas, R.A Montoya-Ospina & E.H. Williams, J.R. (1998). First record of the melonhead whale (Peponocephala electra) for Puerto Rico. Mammalia. 62:452-457.

Peddemors, V.M. (2006). Personal Communications. Sydney: Graduate School of the Environment, Macquarie University.

Peddemors, V.M. & G.J.B. Ross (1988). First record of the melon-headed whale Peponocephala electra (Gray, 1846) for the East African coast. African Journal of Ecology. 26:345-346.

Peddemors, V.M. & R. Harcourt (2006). Personal Communication. Sydney: Graduate School of the Environment, Macquarie University.

Perryman, W.L. (2002). Melon-headed whale - Peponocephala electra. In: Perrin W.F., B. Wursig & J.G.M. Thewissen, eds. Encyclopedia of Marine Mammals. Page(s) 733 - 735. San Diego: Academic Press.

Perryman, W.L., D.W.K. Au & T.A .Jefferson Leatherwood S (1994). Melon-headed whale - Peponocephala electra. Ridgway S.H. & S.R. Harrison, eds. Handbook of Marine Mammals. 5:363-386. 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.

Reyes, J.C. (1991). The conservation of small cetaceans: a review. Report prepared for the Secretariat of the Convention on the Conservation of Migratory Species of Wild Animals. UNEP/CMS Secretariat, Bonn.

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:

Wade P. & T.Gerrodette (1993). Estimates of cetacean abundance and distribution in the eastern tropical Pacific. Report of the International Whaling Commission. 43:477-493.

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.

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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 (2014). Peponocephala electra in Species Profile and Threats Database, Department of the Environment, Canberra. Available from: Accessed Tue, 23 Sep 2014 00:31:37 +1000.