NE
Conservation Status

Not Evaluated
Species

Has not yet been evaluated against IUCN criteria.
1,629 Species
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Overview

Understanding This Status

Not Evaluated (NE) means a species has not yet been assessed against the IUCN Red List Categories and Criteria. It indicates that no IUCN Red List evaluation has been completed for the species at the time of listing.

Not Evaluated is used for taxa that have not been formally assessed under the IUCN Red List Categories and Criteria. This can occur because the species is newly described, data have not yet been compiled for an assessment, priorities have focused on other groups or regions, or an assessment is planned but not completed. NE is therefore a status about the assessment process-not a statement about population size, trend, threats, or extinction risk.

This status can apply to any taxonomic group and any geographic area, including common, widespread species as well as rare or poorly known ones. Because NE provides no information on risk, it should not be treated as equivalent to "Least Concern," "Data Deficient," or any threatened category. In practice, NE highlights that conservation decision-makers, researchers, and the public lack an IUCN-based risk classification for the species.

NE matters because unassessed species can be overlooked in conservation planning, funding, and policy tools that rely on Red List categories. It underscores the need for targeted research and assessment work so that the species can be evaluated consistently and transparently, and-if necessary-prioritized for monitoring, management, and protection.

Common Misconceptions

IUCN Standards

Assessment Criteria

A species is listed as Not Evaluated (NE) when it has not yet been assessed against the IUCN Red List Categories and Criteria. NE does not imply anything about extinction risk (high or low); it only indicates that a formal Red List evaluation has not been completed or published for that taxon.

How species are assessed: NE is assigned when no Red List assessment has been carried out (or finalized/published) for the species under the IUCN Red List Categories and Criteria. Because the assessment has not been completed, none of the criteria (A-E) are applied and no extinction-risk category is inferred. NE can occur for newly described taxa, taxa not yet prioritized for assessment, or taxa awaiting assessment updates/publication.

≈1.9-2.0 million species globally (roughly the described species that have not yet received an IUCN Red List assessment) Species Globally
≈0% of IUCN-assessed species (NE are, by definition, not assessed); equivalently, ≈92-93% of described species remain unassessed Of Assessed Species
↑ Increasing

In absolute terms, the NE pool tends to grow because new species are described faster than they can be formally assessed, and assessment capacity is constrained by funding, data availability, and taxonomic expertise. Although IUCN assessments are increasing over time, they generally do not keep pace with ongoing species discovery and the very large backlog of undescribed/poorly known diversity (especially among invertebrates and fungi).

Geographic Patterns: NE species are concentrated where biodiversity is high and baseline survey/monitoring is limited: tropical forests (Amazon Basin, Congo Basin, Southeast Asia, New Guinea), tropical mountain regions with high endemism (e.g., Andes, Southeast Asian highlands), and remote/under-sampled systems such as deep-sea habitats, complex coral-reef-associated fauna, and many tropical freshwater basins. Small islands and karst/cave systems also contribute disproportionately because they contain many narrowly endemic species that are often newly described and data-poor.

Implications

What This Means

For the Species

  • The species' extinction risk is unknown because it has not been assessed against IUCN Red List criteria.
  • Not Evaluated does not imply the species is safe or threatened; it only indicates a lack of formal IUCN assessment.
  • The species could be common, rare, declining, or even highly threatened-NE provides no direct signal of population trend or threat level.
  • Conservation actions may be delayed or poorly targeted because baseline information (range, population size, threats) may be incomplete or not synthesized.
  • If threats exist (habitat loss, exploitation, disease, climate impacts), they may go unrecognized in global prioritization processes until an assessment is completed.

Conservation Priority

Typically a data-and-assessment priority rather than an immediate threat-based priority: conservationists often prioritize NE species for surveys, monitoring, and Red List assessment when there are signals of risk (restricted range, rapid habitat loss, heavy trade/harvest, known declines) or when the species is endemic, taxonomically unique, or poorly studied. In practice, NE species may receive lower attention than already-assessed threatened species unless there is strong evidence or precautionary concern.

Legal Protections

  • CITES: May still be listed on CITES Appendices I/II/III based on trade risk; NE does not affect CITES listing status.
  • U.S. ESA (Endangered Species Act): May be listed as Endangered/Threatened (or be a candidate species) regardless of IUCN status; NE does not prevent ESA protections.
  • EU framework: The EU Wildlife Trade Regulations can restrict trade independently of IUCN status; species may also be protected under the EU Habitats Directive or Birds Directive if covered.
  • National and subnational laws: Many countries protect native wildlife via endangered species acts, hunting regulations, habitat protection laws, and protected-area rules independent of IUCN assessment.
  • CMS (Convention on Migratory Species): Migratory species may be listed on CMS Appendices and gain cooperative protections regardless of IUCN status.
  • Regional agreements and directives (e.g., Bern Convention, OSPAR, ASEAN wildlife frameworks): May apply based on regional conservation priorities rather than IUCN category.
  • Fisheries/forestry regulations: Harvest quotas, bycatch rules, and land-use protections can apply even if a species is NE.

Funding Implications

NE status often limits eligibility for funding streams tied explicitly to IUCN threatened categories (e.g., projects restricted to CR/EN/VU species) and can weaken urgency in donor decision-making. However, NE species can still attract support for baseline research, field surveys, taxonomy, monitoring, and Red List assessments, and may be funded under broader habitat, ecosystem, protected-area, anti-trafficking, or biodiversity-inventory grants. Demonstrating credible threat indicators (e.g., small range, exploitation, habitat loss) can help secure precautionary funding even without a formal IUCN category.

Stories of Change

Status Transitions

Success Stories

Olinguito

not_evaluated least_concern

After being recognized as a distinct species and drawing targeted research attention, improved field knowledge (distribution and habitat use) enabled a formal conservation assessment that did not indicate imminent extinction risk at the global scale. This is a common "NE → LC" pathway driven by taxonomy clarification plus basic range/threat documentation.

Pygmy three-toed sloth

not_evaluated critically_endangered

Once formally evaluated, its extremely restricted range and habitat pressures became central to the assessment outcome. While not a recovery story, it illustrates how moving out of Not Evaluated can reveal elevated risk when a species is range-limited and threatened.

Tapanuli orangutan

not_evaluated critically_endangered

Following recognition as a distinct species, assessment efforts focused on its very small, fragmented population and ongoing habitat threats, resulting in a high-risk category rather than an "administratively neutral" NE status.

Tragic Losses

Tapanuli orangutan

A prominent example of how NE can mask urgency: once evaluated, the species' limited population and continued habitat loss placed it in the highest threatened category short of extinction.

Saola

After discovery and subsequent evaluation, extremely limited confirmed records, intense snaring pressure, and habitat impacts drove assessment into a severe threat category-showing how an NE listing can simply reflect an assessment gap rather than safety.

How You Can Help

Take Action

Conservation Strategies

  • Prioritize rapid baseline assessments (distribution, population size/trends, threats) to move species from NE to an evaluated Red List category.
  • Fill data gaps with targeted field surveys (presence/absence, abundance, breeding sites, habitat use) using standardized protocols and repeatable sampling.
  • Strengthen taxonomic clarity (voucher specimens, DNA barcoding, revised species descriptions) to avoid misidentification and hidden diversity that blocks assessment.
  • Leverage museum/herbarium and citizen-science occurrence records to map range, detect decline signals, and identify survey hotspots.
  • Conduct threat screening and risk triage (land-use change, harvest, invasive species, pollution, climate exposure) to flag candidates for urgent assessment.
  • Implement precautionary habitat protection in known/likely strongholds while evaluation is pending (site safeguards, reduced disturbance, buffer zones).
  • Build local monitoring networks (community rangers, researchers, NGOs) to collect continuous data needed for assessment and management.
  • Develop and publish Species Conservation Profiles/Action Plans even before Red List evaluation when evidence suggests vulnerability.
  • Improve data accessibility by publishing to open repositories (GBIF, iNaturalist exports, national biodiversity portals) with clear metadata and georeferencing.
  • Secure funding and capacity for assessments (training IUCN assessors, supporting Red List Authority Specialist Groups, regional workshops).

How You Can Help

  • Record and submit verified sightings to reputable platforms (iNaturalist, eBird, local biodiversity portals) with clear photos/audio, date, precise location (or obscured for sensitive species), and habitat notes.
  • Support or join local bioblitzes and targeted survey efforts aimed at under-documented taxa (invertebrates, fungi, plants) to generate occurrence data needed for evaluation.
  • Contribute to digitization/transcription projects for museum/herbarium collections (e.g., Notes from Nature, Zooniverse biodiversity projects) to unlock historical distribution data.
  • If qualified, partner with researchers/NGOs to collect standardized monitoring data (transects, camera traps, acoustic recorders) and share datasets openly with metadata.
  • Report suspected threats and changes at known sites (new development, illegal harvest, pollution events, invasive species) to local conservation authorities and site managers.
  • Advocate for precautionary protection of habitats that likely contain NE species (support protected area expansion, oppose destructive projects, request environmental impact assessments include poorly known taxa).
  • Fund or donate to assessment and survey work (grants to local NGOs/universities; support IUCN SSC Specialist Group work, BGCI for plants, or regional assessment workshops).
  • Avoid purchasing wildlife, plants, or products of uncertain origin-especially from online marketplaces-since unassessed species can be quietly overexploited.
  • Practice and promote biosecurity (clean boots/gear between sites, don't release pets or bait) to reduce spread of pathogens and invasives that may threaten unassessed species.
  • Promote open data by encouraging local projects to publish records to GBIF or national portals and by using Creative Commons licensing when appropriate.
  • Participate in community science for understudied groups (moths, beetles, fungi, freshwater invertebrates) by setting up light sheets, camera traps, or audio recorders and sharing results with experts.
  • Support Indigenous and local community-led stewardship and monitoring programs that can rapidly improve knowledge of NE species in their territories.

All Not Evaluated Species

1,629 species documented in our encyclopedia