Extinction threat to indigenous land species – published April 2021
30 March 2023: This indicator has been updated. See Extinction threat to indigenous species.
What is measured
We report on the extinction threat to indigenous, resident, living land species that have been assessed by expert panels under the New Zealand Threat Classification System (NZTCS). They include bats, frogs, reptiles, terrestrial invertebrates, vascular plants, non-vascular plants (mosses, hornworts, and liverworts), lichens and terrestrial birds (which exclude seabirds and shorebirds, which are reported under conservation status of indigenous marine species).
Why it is important
Many of New Zealand’s indigenous plants and animals are endemic – found nowhere else in the world – and are our national taonga (treasure). New Zealand species make a significant contribution to global biodiversity, which is important for ecosystem processes and resilience, culture, and recreation. Indigenous species have particular importance to Māori, whose mātauranga (knowledge systems), tikanga (cultural practice), and mahinga kai (traditional food resources) are dependent on the wellbeing of indigenous species. Understanding the status of indigenous land species provides vital information for New Zealand conservation and kaitiaki decision-making.
Key findings
Many of our indigenous land species are threatened with extinction or at risk of becoming threatened:
- 84 percent of reptile species (89 of 106)
- 80 percent of bat species (4 of 5)
- 75 percent of frog species (3 of 4)
- 74 percent of terrestrial bird species (78 of 105)
- 46 percent of vascular plant species (1253 of 2744)
- 19 percent of hornworts and liverwort species (146 of 760).
Many of our indigenous land species populations are expected to decline further:
- 46 percent of reptile species populations are expected to decrease (49 of 106), compared with 5 percent expected to increase (5 of 106)
- 60 percent of bat species populations are expected to decrease (3 of 5), compared with 20 percent expected to increase (1 of 5)
- 50 percent of frog species populations are expected to decrease (2 of 4), with none expected to increase (0 of 4)
- 2 percent of hornworts and liverwort species populations are expected to decrease (16 of 760), with none expected to increase (0 of 760)
These expected population trends are made for the longer of 10 years or three generations of the particular species.
Where this data comes from
Department of Conservation
View data tables
You can also download data from the visualisation tool on this page. However, the data from the tool does not contain metadata, and does not have the same name as the data tables.
Related indicators
Conservation status of indigenous land species
Conservation status of indigenous freshwater species
Conservation status of indigenous marine species
Related content
New Zealand Threat Classification System (online database)
New Zealand Threat Classification System reports
About the data
We report on the extinction threat and expected population trend of New Zealand’s indigenous, resident, living species assessed after 2008.
The Department of Conservation (DOC) developed the New Zealand Threat Classification System (NZTCS) to provide a national system that is similar to the International Union for Conservation of Nature and Natural Resources Red List. Experts assign a threat of extinction status through a DOC-led process, based on criteria of abundance, distribution, and expected change in population over time. The criteria are used to monitor the status of individual species, and report on the state of indigenous biodiversity (Townsend et al, 2008).
Species are given extinction threat classification categories of ‘threatened’, ‘at risk’, ‘data deficient’, or ‘not threatened’. ‘Threatened’ is a higher extinction threat than ‘at risk’. The ‘threatened’ category is made up of the following subcategory classifications in order from higher risk to lesser high risk: ‘nationally critical’, ‘nationally endangered’ and ‘nationally vulnerable’. The ‘at risk’ category is made up of the following subcategory classifications in order from higher risk to lesser risk: ‘declining’, ‘recovering’, ‘relict’, and ‘naturally uncommon’.
Data-deficient species are those where an assessment was made that there is not sufficient population information available to determine the extinction threat classification. The quantitative criteria for each subcategory is provided in table 2 and table 3 of the NZTCS manual 2008.
Species are assessed under differing NZTCS assessment reports independently of each other, which means that species assessment years vary.
The expected population trend is estimated for the longer of 10 years or three generations from the assessment year. A generation is the average age of breeding adults. Expectations are based on historic, current, and expected threats and management.
Our analysis includes species that are:
- indigenous – native to New Zealand
- resident – breeds in New Zealand (or greater than 25 percent of the world population spends more than 50 percent of their time in New Zealand)
- living – not known to be extinct
- assessed since 2008 – in accordance with the latest NZTCS manual 2008
- taxonomically determinate – generally accepted by relevant experts as distinct units
- taxonomically unresolved – not formally resolved and named; or those that have been formally described but relevant experts doubt their validity.
We created species groups that are intended to be easily understandable for non-technical users, so that statistics on the extinction threat and expected population trends of these groups can be provided to users.
We have separated groups into those where all known species have been assessed and those where only some known species have been assessed. Our understanding of the extinction threat and expected population trend differs by species group. Some groups do not have all known species assessed, such as mosses and terrestrial invertebrates. Conclusions on these groups cannot be made. Other groups have all known species assessed, but there are high proportions of data-deficient species, such as lichens. Conclusions on these groups should be made with care.
Data quality
The accuracy of the data source is of medium quality.
Extinction threat to indigenous land species is a direct measure of the ‘Land species, taonga species, and genetic diversity’ topic.
Stats NZ and the Ministry for the Environment must report on topics related to the five environmental domains: air, atmosphere and climate, fresh water, land, and marine. These topics identify key issues within each domain.
Topics for environmental reporting describes the topics for each domain.
Data quality information has more information about the criteria we use to assess data quality.
References
Townsend, A. J., de Lange, P. J., Duffy, C. A. J., Miskelly, C. M., Molloy, J., & Norton, D. A. (2008). New Zealand Threat Classification System manual. Retrieved from https://www.doc.govt.nz/about-us/science-publications/conservation-publications/nz-threat-classification-system/nz-threat-classification-system-manual-2008/
Archived pages
Archived April 2021:
