|Scientific Name:||Feresa attenuata|
|Species Authority:||Gray, 1875|
|Red List Category & Criteria:||Data Deficient ver 3.1|
|Assessor/s:||Taylor, B.L., Baird, R., Barlow, J., Dawson, S.M., Ford, J., Mead, J.G., Notarbartolo di Sciara, G., Wade, P. & Pitman, R.L.|
|Reviewer/s:||Hammond, P.S. & Perrin, W.F. (Cetacean Red List Authority)|
This species is naturally uncommon. The combination of potential declines driven by impacts from high intensity anthropogenic sounds and bycatch in fisheries is believed sufficient that a 30% global reduction over three generations cannot be ruled out.
|Range Description:||This is a tropical/subtropical species that inhabits oceanic waters around the globe generally between 40°N and 35°S. It does not generally approach close to shore, except in some areas where deep, clear waters are very close to the coast (such as around oceanic archipelagos like Hawaii). Reports of its occurrence in the Mediterranean Sea, while common in the literature, are not supported by authenticated records. It is also doubtful whether it occurs regularly in the Red Sea or Persian Gulf (Leatherwood et al. 1991). A few high-latitude strandings and sightings are thought to be extralimital records, and are generally associated with incursions of warm water (Ross and Leatherwood 1994; Donohue and Perryman 2002; Williams et al. 2002).|
Native:Algeria; Anguilla; Antigua and Barbuda; Aruba; Australia; Bahamas; Bangladesh; Barbados; Belize; Benin; Brazil; Brunei Darussalam; Cambodia; Cameroon; Cayman Islands; China; Cocos (Keeling) Islands; Colombia; Comoros; Congo; Congo, The Democratic Republic of the; Cook Islands; Costa Rica; Côte d'Ivoire; Cuba; Curaçao; Djibouti; Dominica; Dominican Republic; Ecuador; El Salvador; Equatorial Guinea; Fiji; France; French Guiana; French Polynesia; Gabon; Gambia; Ghana; Grenada; Guam; Guatemala; Guinea; Guinea-Bissau; Guyana; Haiti; Honduras; India; Indonesia; Iran, Islamic Republic of; Italy; Jamaica; Japan; Kenya; Kiribati; Korea, Republic of; Liberia; Madagascar; Malaysia (Peninsular Malaysia, Sabah, Sarawak); Maldives; Marshall Islands; Mauritania; Mayotte; Mexico; Micronesia, Federated States of ; Morocco; Mozambique; Myanmar; Nauru; Netherlands Antilles (Bonaire, Netherlands Leeward Is.); New Caledonia; Nicaragua; Nigeria; Niue; Northern Mariana Islands; Oman; Pakistan; Palau; Panama; Papua New Guinea; Peru; Philippines; Pitcairn; Portugal; Puerto Rico; Saint Kitts and Nevis; Saint Vincent and the Grenadines; Samoa; Senegal; Sierra Leone; Singapore; Solomon Islands; Somalia; South Africa; Spain; Sri Lanka; Suriname; Taiwan, Province of China; Tanzania, United Republic of; Thailand; Timor-Leste; Togo; Tokelau; Tonga; Trinidad and Tobago; United States; Venezuela, Bolivarian Republic of; Viet Nam; Virgin Islands, British; Virgin Islands, U.S.; Wallis and Futuna; Western Sahara; Yemen
|FAO Marine Fishing Areas:||
Atlantic – eastern central; Atlantic – southeast; Atlantic – southwest; Atlantic – western central; Indian Ocean – eastern; Indian Ocean – western; Pacific – eastern central; Pacific – northwest; Pacific – southeast; Pacific – southwest; Pacific – western central
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||Although there is little information on the population biology of this species, the pygmy killer whale appears to be naturally uncommon. Wade and Gerrodette (1993) estimated that there were about 38,900 (CV=31%) of these whales in the eastern tropical Pacific. There are estimated to be 817 (CV=112%) in the Hawaiian portion of the US EEZ, and 408 (CV=60%) in the northern Gulf of Mexico (Barlow 2006; Mullin and Fulling 2004).|
|Habitat and Ecology:||
The pygmy killer whale occurs in deep, warm waters, generally beyond the edge of the continental shelf, and rarely close to shore (except near some oceanic island groups where the water is deep and clear). This species is mainly tropical, but occasionally strays into warm temperate regions.
Little is known of the diet of this species, although it is known to eat fish and squid. It has occasionally been recorded attacking dolphins, at least those involved in tuna fishery interactions in the eastern tropical Pacific (Perryman and Foster 1980).
Because of their relatively low abundance, even small takes in localized areas could be significant. Although there is considerable controversy regarding the absolute level of declines, there is good evidence of large-scale reductions in many predatory fish populations (e.g., Baum et al. 2003, 2005; Sibert et al. 2006; Polacheck 2006) and over-fishing and collapse of several important “prey” fish stocks world-wide (e.g., Jackson et al. 2001). The effects of such fish population reductions and subsequent ecosystem changes on world-wide populations of pygmy killer whales are unknown but could result in population declines.
Predicted impacts of global climate change on the marine environment may affect pygmy killer whales, although the nature of impacts is unclear (Learmonth et al. 2006).
This species, like 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) and have been a part of multi-species unusual stranding events in Taiwan (Wang and Yang, 2006).
Pygmy killer whales have been killed directly in both harpoon and driftnet fisheries (Caribbean islands, Sri Lanka, Taiwan and Indonesia) and incidentally in various types of fishing gear (most areas of the species’ range).
A few individuals are known to be taken in drives and in driftnets in various regions, most notably Japan and Sri Lanka (Ross and Leatherwood 1994). Reports on the small-cetacean fisheries of St Vincent and Lamalera suggest that pygmy killer whales form a very small proportion of the catch and that catches probably have little impact on the subpopulations in those areas. In Sri Lanka, there is mortality of this species due to harpooning of dolphins for use as bait on long-lines for sharks, billfish, and other oceanic fishes (Ross and Leatherwood 1994).
Although they comprise less than 2% of all cetaceans in monitored by-catches in gillnet fisheries in Trincomalee, Sri Lanka and in villages on the south-west coast of Sri Lanka, this may amount to 300 - 900 pygmy killer whales each year (Ross and Leatherwood 1994). The numbers of animals killed incidentally in net fisheries, such as those in Sri Lanka, may be much higher than is so far documented, because monitoring of these widespread activities is incomplete. In the long term, such takes may have a significant impact on pygmy killer whales where their distribution overlaps with extensive gillnetting operations (Ross and Leatherwood 1994). Small incidental catches are known in fisheries in other areas including the Philippines and Taiwan (Ross and Leatherwood 1994, Dolar 1994, J. Wang pers. comm. 2007).
Evidence from stranded individuals of several similar species indicates that they have swallowed discarded plastic items, which may eventually lead to death (e.g. Scott et al. 2001); this species may also be at risk.
This species does not appear to be particularly abundant anywhere that it has been sighted. In Hawaii, subpopulations appear to be small, and this, along with their limited movements, suggests the species may be particularly vulnerable to human impacts regionally.
|Conservation Actions:||The species is listed on Appendix II of CITES. Research is needed to determine the impact of potential threats on this species.|
|Citation:||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. Feresa attenuata. In: IUCN 2013. IUCN Red List of Threatened Species. Version 2013.2. <www.iucnredlist.org>. Downloaded on 21 April 2014.|
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