Classification of wildlife

In the Northern Territory (NT) every species of plant and animal is classified according to the International Union for the Conservation of Nature (IUCN) red list categories and criteria.

Species are assessed against five criteria (A to E) that consider all of the following:

  • population size, including number of sub-populations
  • the area occupied by the species and the size of its population
  • the number of locations where the species has been found
  • any trends or changes to the characteristics above.

The assessment gives each species a status that relates to its risk of extinction.

Read the guidelines for using the IUCN red list categories and criteria.

The status of species within the NT might be different to their status in other states or at the national level.

The last review of species conservation status within the NT was done in 2012.

Read more on the conservation status of native wildlife in NT.

Categories for classification

Extinct (EX)

A species is extinct when there is no reasonable doubt that the last individual has died. To call a species extinct, there must have been surveys carried out to look for the species across its previously known range. The survey needs to also consider the life cycle of the species and the times of year when it might be located there.

Extinct in the wild (EW)

A species is extinct in the wild when it is known only to survive in cultivation, in captivity or as a naturalised population/s outside the range they once lived in.

Calling a species needs for there to have been similar surveys to those done for extinct species.

Critically endangered (CR)

A species is critically endangered when all the evidence shows that the species meets at least one of the IUCN criteria A to E for critically endangered.

It is then at an extremely high risk of extinction in the wild. In cases where a species may be extinct but where not all surveys have been done to show the species absence, the species may be classified in a possibly extinct subcategory.

These species are considered threatened in the NT.

Endangered (EN)

A species is endangered when all evidence shows that it meets at least one of the IUCN criteria A to E for endangered species, indicating it is facing a high risk of extinction in the wild.

These species are considered threatened in the NT.

Vulnerable (VU)

A species is vulnerable when all the evidence shows that it meets at least one of the IUCN criteria A to E for vulnerable, indicating that it is facing a high risk of extinction in the wild.

These species are considered threatened in the NT.

Near threatened (NT)

A species is near threatened when it is not classified in one of the above threatened categories, but it is close to being or is likely to be in a threatened category soon.

Least concern (LC)

A species is least concern when there is sufficient information available to make an assessment and it is not classified as critically endangered, endangered, vulnerable or near threatened.

Species that are widespread with high numbers are in this category.

Data deficient (DD)

A species is data deficient when there is not enough information to make a direct, or indirect, assessment of its risk of extinction based on distribution and/or population.

Data deficient is not a category of threatened species, but data deficient species should not be assumed to be safe.

A species in this category may be well studied and well known but there is not enough specific data on numbers and distribution.

Species in this category need more information and future research will probably show that they need to be classified as threatened.

Not evaluated (NE)

A species is not evaluated when it is has not been assessed against the criteria. This may be because the species is a rare visitor to the Territory or that the taxonomy of the species has recently changed or is unclear.

Threatened species

Species that have been classified as extinct in the wild, critically endangered, endangered or vulnerable are threatened species and have greater protection in the NT under the Territory Parks and Wildlife Conservation Act.

Numbers of threatened species in each category are shown in bold in the table below.

Find out about threatened animals and threatened plants.

Classifications of NT species

The numbers of species and subspecies in each category for each of the major groups are listed below.

GroupEXEWCRENVUNTLCDDNETotal
Mammals 16 1 4813 17 63 23 2 147
Birds 2 0 5319 34 291 18 57 429
Reptiles 0 0 1312 8 243 43 0 310
Frogs 0 0 0 0 1 1 46 5 0 53
Invertebrates 0 0 2425 5 110 45 >50,000 191
(animal total) 18 1 121870 65 753 137 59 1133
Plants 0 0 32454 417 3148 862 7 4515
Total 18 1 1542124 482 3901 999 66 5648
Fish* 0 0 0 17 5 562 94 >100 669

* Threatened fish species are not listed under the Territory Parks and Wildlife Conservation Act, but many of these species are protected in regulations under the Fisheries Act.

Last updated: 24 July 2017