Occurrence Facet Aggregation
gbif_occurrence_facetsRead-onlyIdempotent
Aggregate occurrence counts across a dimension (COUNTRY, STATE_PROVINCE, YEAR, BASIS_OF_RECORD, DATASET_KEY, KINGDOM_KEY, etc.). Returns one page of facet values ranked by count descending — the top facetLimit at facetOffset 0, a later slice of the same ranking past that. No record payloads returned. Core tool for distribution analysis and trend queries: "which countries have the most records for this species?", "how has observation volume changed since 2010?". Scope the aggregation with taxonKey, country (uppercase ISO 3166-1 alpha-2), publishingCountry, stateProvince, year, geometry, basisOfRecord, datasetKey, occurrenceStatus, or iucnRedListCategory filters. Also the way to split a result set too large for gbif_search_occurrences to page (offset+limit caps at 100,001): facet by DATASET_KEY, then search each datasetKey on its own. Aggregates sightings only by default, matching gbif_search_occurrences and gbif_count_occurrences; to measure the presence/absence split itself, pass facet OCCURRENCE_STATUS with occurrenceStatus ANY.
Input Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
| year | No | Year or year range (e.g., "2020,2024") to scope the aggregation. Both endpoints inclusive. Omit the field to aggregate across every year — a blank or whitespace-only value is rejected rather than dropped, because GBIF answers one with the unfiltered aggregation. | |
| facet | Yes | Dimension to aggregate by (e.g., COUNTRY, YEAR, BASIS_OF_RECORD, SPECIES_KEY, OCCURRENCE_STATUS, IUCN_RED_LIST_CATEGORY). DATASET_KEY is the dimension to split on when a result set is too large to page: every occurrence carries exactly one datasetKey, so its buckets sum to totalOccurrences with no gap and no overlap, and it has the cardinality to cut a large scope into pageable pieces. BASIS_OF_RECORD and PUBLISHING_COUNTRY are gap-free too and both have a matching filter on the occurrence tools, so either can drive a further split of a bucket still too large — but on that same scope they return 9 and 41 buckets against DATASET_KEY's 550, so neither replaces it as the first cut. A dimension a record can lack silently drops that record: faceting one 60,290,950-record scope by YEAR returned 224 buckets summing to 59,407,400, leaving 883,550 undated records in no bucket at all, and MONTH, STATE_PROVINCE, and SPECIES_KEY lose records the same way — stateProvince included, even though the occurrence tools can now filter on it. Sums are comparable only across the same occurrenceStatus scope. | |
| country | No | ISO 3166-1 alpha-2 code, uppercase, of where the occurrence was recorded, to scope to one country. Not the publisher's country — that is publishingCountry, and the two disagree on most records. Scope to one country, or pass back a value this tool returned under facet COUNTRY to drill into that bucket. Lowercase and alpha-3 forms ("gb", "USA") match nothing upstream, which is why only the uppercase two-letter form is accepted here. | |
| geometry | No | WKT polygon to scope the aggregation to a geographic area (e.g., POLYGON((8 47, 9 47, 9 48, 8 48, 8 47))). Coordinates are longitude latitude. Omit the field to aggregate everywhere — a blank or whitespace-only value is rejected rather than dropped, because GBIF answers one with the unfiltered aggregation. | |
| taxonKey | No | Backbone taxon key to scope the aggregation. Matches the given taxon and all descendant taxa (subspecies, varieties, etc.). | |
| datasetKey | No | Scope the aggregation to a single dataset by its GBIF dataset UUID (8-4-4-4-12 hex). Obtain one from gbif_search_datasets, gbif_get_dataset, a DATASET_KEY facet, or the datasetKey field on an occurrence record. Omit the field to aggregate across every dataset — an empty string is rejected rather than read as no scope, because GBIF answers a blank datasetKey with the unfiltered aggregation. | |
| facetLimit | No | Maximum number of facet values to return (default 10, max 100). | |
| facetOffset | No | Zero-based offset into the ranked facet values, for paging past the first facetLimit values on high-cardinality dimensions like DATASET_KEY. Advance by facetLimit to fetch the next page (0, then facetLimit, then 2×facetLimit, …). | |
| basisOfRecord | No | Scope to a specific basis of record. | |
| stateProvince | No | State, province, or first-level administrative division, matched as a verbatim string — exact and case-sensitive. Pass back a value this tool returned under facet STATE_PROVINCE rather than a guessed one: GBIF stores what each dataset recorded without normalizing it, so "England", "England - Greater London", and "Greater London" are three distinct values, "england" is none of them, and an unmatched value aggregates zero records rather than erroring. Omit the field to aggregate across every state or province — a blank or whitespace-only value is rejected rather than dropped, because GBIF answers one with the unfiltered aggregation. | |
| occurrenceStatus | No | Presence/absence scope. Defaults to PRESENT so the aggregation counts sightings, not the surveys that looked and found nothing, and agrees with gbif_count_occurrences on the same filters. Use ANY for both — required to see both buckets when facet is OCCURRENCE_STATUS — or ABSENT for non-observations alone. | PRESENT |
| publishingCountry | No | ISO 3166-1 alpha-2 code, uppercase, of the organization that published the record — not where the occurrence was observed, which is country. Scope to one publisher country, or pass back a value this tool returned under facet PUBLISHING_COUNTRY to drill into that bucket. Lowercase and alpha-3 forms ("us", "USA") match nothing upstream, which is why only the uppercase two-letter form is accepted here. | |
| iucnRedListCategory | No | Scope to records whose taxon carries this IUCN Red List category: CR Critically Endangered, EN Endangered, VU Vulnerable, NT Near Threatened, LC Least Concern, DD Data Deficient, EX Extinct, EW Extinct in the Wild, CD Conservation Dependent. Leave unset and facet on IUCN_RED_LIST_CATEGORY to see the whole distribution instead. |
Output Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
| cap | No | facetLimit applied when the page was capped. Re-call with facetOffset advanced by this value to page on. Absent otherwise. | |
| error | No | Present when the call failed. Absent on success. | |
| facet | No | The facet dimension aggregated. | |
| shown | No | Facet values returned in this page when the page was capped. Absent otherwise. | |
| counts | No | Facet values ranked by count descending — one page of up to facetLimit entries starting at facetOffset, not necessarily the top ones. | |
| notice | No | Guidance when no facet values were returned, the page came back full and more values may remain, a verbatim stateProvince filter matched nothing, or a presence/absence filter narrowed the aggregation. Absent only when none applies. | |
| truncated | No | Heuristic continuation flag: present and true when this page returned a full facetLimit of values, so more distinct values may exist past facetOffset + facetLimit. GBIF exposes no total distinct-value count, so this is an estimate, not exact. Absent when the page came back short, which is the only proof the ranking is exhausted. | |
| facetLimit | No | Maximum facet values requested. | |
| facetOffset | No | Zero-based offset applied to the ranked facet values. | |
| occurrenceStatus | No | The presence/absence filter applied upstream — PRESENT, ABSENT, or ANY when no filter was sent. Says what totalOccurrences and every bucket cover. | |
| totalOccurrences | No | Total matching occurrences across all facet values. |