Introduction to the WDC Species Guide

Everyone wants to learn about whales, dolphins and porpoises so WDC have put together a comprehensive guide to the 89 species currently recognised. You can find out more about the various species of whales, dolphins and porpoises and the threats that they face below.

The Evolution of Whales and Dolphins

The traditional understanding of cetacean (whales, dolphins and porpoises) evolution was that they were descended from hoofed land-mammals, but more recent molecular data suggests a close relationship to the ‘artiodactyls’, an order of even-toed ungulates which includes the giraffe, camel and hippopotamus. In time it may be that cetaceans will be considered a suborder of a more inclusive order Cetartiodactyla, but for the moment they remain classified as belonging to the order Cetacea.

The order Cetacea is further divided into two suborders: Mysticeti – the baleen whales (comprising 4 families, 6 genera and 14 species), and Odontoceti – the toothed whales (comprising 10 families, 33 genera and 75 species), representing a total of some 89 currently recognised species of whales, dolphins and porpoises.

Further along the taxonomic tree, cetacean genetics are still at an early stage for many taxa, with differing views on where one species begins or ends. In several cases, what are currently regarded as single species appear, in fact, to be two or more. For example, the two distinct populations of the species Sotalia fluviatilis were recently reclassified as two distinct species - Sotalia fluviatilis, the “tucuxi” being the river population and Sotalia guianensis, the “costero”, the coastal marine or Guiana dolphin. There is also strong genetic evidence for the long held view, due to marked differences in behaviour, feeding preferences and physical appearance, that there are in fact several species in the Orcinus genera, currently classified together as Orcinus orca.

Find out more about the world of whales and dolphins by suborder or family or directly through our species guide.

What do the various "Listings" mean?

The Species Guide has a series of listings. These cover the major conventions that afford protection for whales and dolphins and we believe are a useful way of giving some indication of how the global community has sought to consider the relative level of threats affecting whales and dolphins. Whilst these listings can be a useful starting point, it must be remembered that some countries do not wish to see protection afforded to whales and dolphins and so these listings are somewhat subject to political pressures within the various conventions and agreements.

The IUCN Red List of Threatened Species

The IUCN Red List Categories and Criteria are intended to be an easily and widely understood system for classifying species at high risk of global extinction. The general aim of the system is to provide an explicit, objective framework for the classification of the broadest range of species according to their extinction risk. However, while the Red List may focus attention on those taxa at the highest risk, it is not the sole means of setting priorities for conservation measures for their protection. Additionally, even though a species may not be afforded the highest protection in some cases it is imperative that individual populations are. 

EXTINCT (EX)

A taxon is Extinct when there is no reasonable doubt that the last individual has died. A taxon is presumed Extinct when exhaustive surveys in known and/or expected habitat, at appropriate times (diurnal, seasonal, annual), throughout its historic range have failed to record an individual. Surveys should be over a time frame appropriate to the taxon's life cycle and life form.

EXTINCT IN THE WILD (EW)

A taxon is Extinct in the Wild when it is known only to survive in cultivation, in captivity or as a naturalised population (or populations) well outside the past range. A taxon is presumed Extinct in the Wild when exhaustive surveys in known and/or expected habitat, at appropriate times (diurnal, seasonal, annual), throughout its historic range have failed to record an individual. Surveys should be over a time frame appropriate to the taxon's life cycle and life form.

CRITICALLY ENDANGERED (CR)

A taxon is Critically Endangered when the best available evidence indicates that it meets any of the criteria A to E for Critically Endangered (see Section V), and it is therefore considered to be facing an extremely high risk of extinction in the wild.

ENDANGERED (EN)

A taxon is Endangered when the best available evidence indicates that it meets any of the criteria A to E for Endangered (see Section V), and it is therefore considered to be facing a very high risk of extinction in the wild.

VULNERABLE (VU)

A taxon is Vulnerable when the best available evidence indicates that it meets any of the criteria A to E for Vulnerable, and it is therefore considered to be facing a high risk of extinction in the wild.

NEAR THREATENED (NT)

A taxon is Near Threatened when it has been evaluated against the criteria but does not qualify for Critically Endangered, Endangered or Vulnerable now, but is close to qualifying for or is likely to qualify for a threatened category in the near future.

LEAST CONCERN (LC)

A taxon is Least Concern when it has been evaluated against the criteria and does not qualify for Critically Endangered, Endangered, Vulnerable or Near Threatened. Widespread and abundant taxa are included in this category.

DATA DEFICIENT (DD)

A taxon is Data Deficient when there is inadequate information to make a direct, or indirect, assessment of its risk of extinction based on its distribution and/or population status. A taxon in this category may be well studied, and its biology well known, but appropriate data on abundance and/or distribution are lacking. Data Deficient is therefore not a category of threat. Listing of taxa in this category indicates that more information is required and acknowledges the possibility that future research will show that threatened classification is appropriate. It is important to make positive use of whatever data are available. In many cases great care should be exercised in choosing between DD and a threatened status. If the range of a taxon is suspected to be relatively circumscribed, and a considerable period of time has elapsed since the last record of the taxon, threatened status may well be justified.

NOT EVALUATED (NE)

A taxon is Not Evaluated when it is has not yet been evaluated against the criteria.

Find out more information on the IUCN classification.

The Convention on the Conservation of Migratory Species of Wild Animals (also known as CMS or Bonn Convention) listings explained

Appendix I - Endangered migratory species

Migratory species that have been categorised as being in danger of extinction throughout all or a significant proportion of their range are listed on Appendix I of the Convention.

Appendix II - Migratory species conserved through Agreements

Migratory species that have an unfavourable conservation status or would benefit significantly from international co-operation organised by tailored agreements are listed in Appendix II to the Convention. For this reason, the Convention encourages the Range States to conclude global or regional Agreements for the conservation and management of individual species or, more often, of a group of species listed on Appendix II.

Find out more information on the CMS listings.

The Convention on Trade in Endangered Species (CITES) listings explained

Appendix I

lists species that are the most endangered among CITES-listed animals and plants. They are threatened with extinction and CITES prohibits international trade in specimens of these species except when the purpose of the import is not commercial, for instance for scientific research. In these exceptional cases, trade may take place provided it is authorised by the granting of both an import permit and an export permit (or re-export certificate).

Appendix II

lists species that are not necessarily now threatened with extinction but that may become so unless trade is closely controlled. It also includes so-called "look-alike species", i.e. species of which the specimens in trade look like those of species listed for conservation reasons. International trade in specimens of Appendix II species may be authorised by the granting of an export permit or re-export certificate. No import permit is necessary for these species under CITES (although a permit is needed in some countries that have taken stricter measures than CITES requires). Permits or certificates should only be granted if the relevant authorities are satisfied that certain conditions are met, above all that trade will not be detrimental to the survival of the species in the wild.

Find out more information about the CITES listings.

International Whaling Convention (IWC)

Whilst the IWC does not actually seek to classify whales by a required level of conservation, the Treaty does allow for restrictions on what whales can and cannot be hunted. You can see the listings on the IWC website.