This is an unofficial, independent compilation. It is not produced, reviewed, or endorsed by the IUCN or the IUCN Red List. It gathers observations noticed while preparing Red List data for use on Wikipedia and Wikidata, and it is shared in the hope that some are useful for a future release.
This page collects observations about the data in IUCN Red List version 2026-1. The tables below group the observations; each links to a description with a short preview, a full sortable list, and a CSV download. The intent is to help with data review for the next release. Every observation may be incomplete or mistaken.
How this was put together, how to read the lists, and its caveats →
Missing data: a record is absent or incomplete. Text cleanup: stray characters or markup in a field. For review: a difference worth a look, not an error. Nothing found: the check found nothing in this release.
Missing and outdated records
Assessments and taxa that are absent, unreachable in the API, or without a current assessment.
| Observation | Type | Rows | Open |
|---|---|---|---|
Assessments whose geographic scope is blank, so any scope filter, including the usual "Global" filter, silently drops them. |
Missing data | 52 | details · full list · csv |
Historical assessment ids that appear in a taxon's API record but return HTTP 404 (not found) when requested directly. |
Missing data | 3 | details · full list · csv |
Assessed subspecies and varieties whose parent species has no assessment of its own, leaving them reachable only by their SIS id. |
Missing data | 358 | details · full list · csv |
Taxa whose assessments are all historical: none is flagged as current, usually because the taxon was removed, merged, or reclassified. |
For review | 4,218 | details · full list · csv |
Text cleanup
Stray whitespace, markup, and values that disagree with each other in name, synonym, and narrative fields.
| Observation | Type | Rows | Open |
|---|---|---|---|
Taxonomy field values with stray whitespace (leading, trailing, doubled, or non-breaking), each with a suggested cleaned-up value. |
Text cleanup | 1,099 | details · full list · csv |
Synonym names with stray whitespace (leading, trailing, doubled, or non-breaking), each with a whitespace-normalised suggestion. |
Text cleanup | 11,827 | details · full list · csv |
Synonym names containing HTML markup, stray HTML entities, or typographic quotes, each with a cleaned plain-text suggestion. |
Text cleanup | 2,802 | details · full list · csv |
Synonyms whose name field contains a bracketed nomenclatural note, such as [orth. error], alongside the name itself. |
Text cleanup | 2,309 | details · full list · csv |
English common names with a likely error or a formatting choice worth checking (species codes, all-capitals text, stray whitespace, backticks standing in for apostrophes), with a tidied suggestion where one is clear. |
Text cleanup | 615 | details · full list · csv |
Assessments whose narrative text differs between the HTML and plain-text CSV exports, often because heavy redundant markup left the plain-text version empty or truncated. |
Text cleanup | 523 | details · full list · csv |
Assessments whose recorded scientific name does not agree with the separate genus, species, and infrarank fields it should be built from. |
Text cleanup | 4 | details · full list · csv |
A field-by-field profile of text irregularities in the taxonomy data, showing which fields have the most stray whitespace or unusual characters. |
For review | 8 | details · full list · csv |
Catalogue of Life crosscheck
Differences found when checking every assessed name against the Catalogue of Life; each is on exactly one of these pages.
| Observation | Type | Rows | Open |
|---|---|---|---|
IUCN names that appear nowhere in the Catalogue of Life, with no close spelling match and no other name for the taxon there either. |
For review | 745 | details · full list · csv |
IUCN names that appear nowhere in the Catalogue of Life, each paired with the most similar CoL spelling and a note on how the two differ. |
For review | 799 | details · full list · csv |
The IUCN name is not in CoL, but one of the taxon's other IUCN-listed names is there as a synonym; a lead to check, not a confirmed match. |
For review | 134 | details · full list · csv |
Assessed IUCN taxa whose name the Catalogue of Life records as a synonym of a different accepted name. |
For review | 11,664 | details · full list · csv |
Genus, family, order, and class names used in the IUCN classification that the Catalogue of Life records only as synonyms. |
For review | 717 | details · full list · csv |
Names whose parent taxon is spelled slightly differently in IUCN and the Catalogue of Life, suggesting the same placement written two ways. |
For review | 94 | details · full list · csv |
Names that match the Catalogue of Life exactly but whose author attribution is spelled slightly differently in the two catalogues. |
For review | 9,343 | details · full list · csv |
The two catalogues accept different names for the same taxon; IUCN's synonym list already links the pair. |
For review | 2,742 | details · full list · csv |
Names the Catalogue of Life places under a genuinely different parent taxon (not just a different spelling of the same one). |
For review | 1,663 | details · full list · csv |