The New Zealand Threat Classification System (NZTCS) is a tool for assigning a threat status to taxa of plants and animals in New Zealand. It was developed by the Department of Conservation (DOC) in collaboration with experts from various institutions and organisations. The NZTCS is intended to complement the global IUCN Red List by providing a more sensitive classification for taxa that are endemic, native or introduced to New Zealand.
The NZTCS was first published in 2002 and revised in 2008. It consists of nine categories and several qualifiers that provide additional information on each taxon. The categories are:
- Extinct: Taxa that have become extinct since humans first visited the New Zealand archipelago (c. 1000 years before present).
- Nationally Critical: Taxa that are facing an extremely high risk of extinction in the wild.
- Nationally Endangered: Taxa that are facing a very high risk of extinction in the wild.
- Nationally Vulnerable: Taxa that are facing a high risk of extinction in the wild.
- Declining: Taxa that are not threatened but are declining in population or area of occupancy.
- Recovering: Taxa that have undergone a decline within the last 1000 years and are now increasing in population or area of occupancy.
- Relict: Taxa that have undergone a large range reduction within the last 1000 years and now exist as remnant populations that are not threatened.
- Naturally Uncommon: Taxa that have naturally small or restricted populations or distributions that are not threatened.
- Not Threatened: Taxa that do not meet the criteria for any of the above categories.
The qualifiers are:
- Conservation Dependent (CD): Taxa whose survival depends on ongoing conservation management.
- Data Poor (DP): Taxa whose status is uncertain due to lack of data.
- Designated (De): Taxa whose status is assigned without applying the criteria due to peculiar circumstances.
- Extinct in the Wild (EW): Taxa that only survive in captivity or cultivation.
- Extreme Fluctuations (EF): Taxa whose population or distribution undergoes extreme and rapid variations.
- Increasing (Inc): Taxa whose population or distribution is increasing (> 10%).
- Island Endemic (IE): Taxa that are endemic to one or more offshore islands of New Zealand.
- One Location (OL): Taxa whose population or distribution is confined to one location, defined as a geographically or ecologically distinct area.
- Partial Decline (PD): Taxa whose population or distribution is declining in part of their range but stable or increasing elsewhere.
- Range Restricted (RR): Taxa whose distribution is naturally confined to specific habitats or geographic areas.
- Recruitment Failure (RF): Taxa whose population is not reproducing successfully or has an ageing structure.
- Secure Overseas (SO): Introduced taxa that are secure in their native range.
- Sparse (Sp): Taxa whose population is naturally scattered over a large area with low density.
- Stable (St): Taxa whose population or distribution is stable (± 10%).
- Threatened Overseas (TO): Introduced taxa that are threatened in their native range.
The NZTCS uses a listing process that involves expert panels, list facilitators, peer review and public consultation. The listing process is carried out every three years for each taxon group. The lists are published by the expert panels in peer-reviewed journals and on the DOC website.
The NZTCS provides a framework for assessing and reporting the status of New Zealand’s biodiversity, as well as informing conservation priorities, management actions, research needs and public awareness. The NZTCS is based on rigorous scientific evidence and transparent criteria, but also acknowledges the limitations and uncertainties inherent in such assessments.