Endemism.org is a data and reference site focused on species that occur naturally within a defined geographic area and nowhere else in their native range. The site brings together endemic-species records, native distributions, taxonomic information, geographic patterns, and quantitative biodiversity data in a format designed for direct reference.
What the site covers
Endemism.org documents endemism at several geographic scales, including countries, islands, archipelagos, mountain systems, river basins, springs, caves, aquifers, and other clearly defined natural areas. Coverage may include animals, plants, freshwater organisms, terrestrial invertebrates, and narrower taxonomic groups when reliable information is available.
Country profiles are built around measurable data rather than general descriptions. Depending on the available evidence, a page may include endemic species counts, endemic shares within native groups, threatened endemic species, endemic genera or families, geographic concentrations, and verified species-level records.
Endemism is based on natural native distribution. Introduced, naturalized, cultivated, captive, or conservation-translocated populations do not expand a species’ original native range.
How species records are treated
Species-level records are kept separate from subspecies, varieties, forms, populations, and other infraspecific units. Accepted scientific names are preferred, and older names are treated as synonyms when current taxonomic sources support that treatment.
A species is not classified as endemic simply because observations are concentrated in one place. Occurrence records can help describe distribution, but endemic status requires evidence about the natural range itself. A lack of records outside an area is not treated as proof that the species occurs nowhere else.
Common names are included only when they can be supported. Scientific names remain the primary identifier for species records.
Data from different sources
Endemic-species numbers can differ between authorities because datasets may use different taxonomic treatments, geographic boundaries, dates, extinction rules, or levels of coverage. A mammal dataset, plant checklist, national biodiversity inventory, and conservation assessment may all describe different biological units.
Counts from incompatible datasets are therefore kept separate. Species, taxa, genera, families, native records, assessed records, and estimated totals are not added together to create an artificial all-species figure.
When both a numerator and denominator come from the same compatible dataset, a percentage may be calculated from those values. The original scope and level of precision are retained so an approximate source value is not presented as an exact measurement.
Geographic precision
Endemism often occurs at a much smaller scale than a national border. A species endemic to a single island, spring system, watershed, mountain range, or cave can also qualify as endemic to the country containing that area, but the narrower supported range provides more useful biological information.
For that reason, species records use the most precise defensible native range available. Regional figures are not presented as national totals, and counts from separate states, provinces, islands, or other areas are not combined unless the underlying source explicitly supports that calculation.
Sources and taxonomy
Information is drawn from specialist taxonomic databases, government biodiversity and wildlife agencies, botanical authorities, conservation databases, museums, universities, and peer-reviewed scientific literature. Source choice depends on the organism group and the type of claim being documented.
Taxonomy changes over time. Species may be split, merged, synonymized, transferred to another genus, or reassessed as new evidence becomes available. These changes can alter endemic-species counts even when the underlying geographic distribution has not changed.
What the site does not do
Endemism.org does not treat a short list of well-known species as a substitute for the available species record. When reliable species identities can be verified, checklists are extended as far as the evidence reasonably allows. When the available evidence supports only a partial or taxon-specific dataset, that narrower scope is retained.
The site also does not create unsupported totals to make different sources appear consistent. Where no defensible all-taxa endemic count exists, independently defined datasets are presented separately.
Corrections and updates
Species distributions, accepted names, conservation assessments, and biodiversity inventories change as new records and taxonomic revisions are published. Pages may therefore be revised when stronger evidence, newer dataset versions, or corrected records become available.
Factual errors, taxonomic changes, distribution corrections, and source issues can be reported through the site’s contact channel. Corrections are evaluated against the underlying biological evidence before published information is changed.