Orcinus orca

Authority-bound identity

Use Orcinus orca (Linnaeus, 1758), retaining its basionym Delphinus orca and NCBI identifier 9733 as traceable name links. [NCBI taxonomy](https://ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?id=9733&lvl=0).

1. Which authority, version and taxon concept define Orcinus orca for this record? definition
2. Which verified GBIF and NCBI records correspond to that concept, and when were they checked? provenance

Classification does not imply equivalence

Retain alternative classifications without splitting the registry entry automatically: NOAA's 2024 stock assessment discusses proposed species recognition and provisional subspecies treatment for residents and Bigg's killer whales. [NOAA stock assessment](https://www.fisheries.noaa.gov/s3/2026-04/final_2024-mmsar_killer-whale.pdf).

1. Does the supplied label identify an ecotype, subspecies, population, stock or social group? boundary
2. What evidence supports membership, and how would a different taxonomic treatment change the claim's coverage? provenance

Traceable individual match

Require inspectable evidence for an individual match and preserve uncertain or conflicting catalogue assignments.

1. Which fin features, saddle markings or genetic comparisons support this identity? provenance
2. Could image angle, injury, image quality or an incomplete catalogue explain an apparent mismatch? measurement

Stage-aware body interpretation

Adult males generally have greater size and taller dorsal fins than females; retain uncertainty for immature animals and avoid deriving reproductive state from size alone. [NOAA species account](https://www.fisheries.noaa.gov/species/killer-whale).

1. Are sex and age based on known history, anatomical evidence or appearance-based estimation? provenance
2. Which observations establish calf dependency, maturity or reproductive state for this animal? measurement

Occurrence is not residency

Orcas occur in every ocean; an occurrence record does not establish year-round residency or the range of a particular population. [NOAA distribution overview](https://www.fisheries.noaa.gov/species/killer-whale/science).

1. Which repeated, dated observations establish seasonal or persistent use of this marine area? measurement
2. Does an apparent absence reflect survey coverage, detection limits or supported departure? boundary

Diet requires population context

Fish-focused resident and marine-mammal-focused Bigg's ecotypes illustrate why prey dependence cannot be inferred from the species name alone. [NOAA feeding overview](https://www.fisheries.noaa.gov/species/killer-whale/science).

1. Is the prey assignment supported by observed feeding, prey remains, molecular analysis or dietary tracers? provenance
2. Does the evidence establish a single feeding event, seasonal use or sustained dependence? boundary

Association is not kinship

Record observed associations, proposed pod membership and documented maternal links as separate claims with their own evidence.

1. Which repeated encounters support a persistent social association rather than a temporary aggregation? measurement
2. What birth history, longitudinal evidence or genetic analysis supports a proposed maternal relationship? provenance

Acoustic attribution limits

Keep call detection, repertoire matching and behavioural interpretation separate; require regional validation before assigning an acoustic record to a population.

1. Which reference recordings and concurrent sightings support the proposed caller or population? provenance
2. How do recording coverage, background noise and overlapping callers limit the interpretation? measurement

Observations before diagnosis

Record body condition, injuries and potential exposures with dates and methods; treat causal attribution as a separate evidential step.

1. What change in body condition, movement or visible injury is documented relative to this animal's history? measurement
2. What evidence connects the change to prey limitation, contaminants, noise, entanglement or another cause? provenance

Unit-specific decisions

Require an assessment's unit, date and authority before applying it; resolve current local protocols before approaching, sampling or attempting assistance.

1. Does the cited assessment concern the global taxon or the population involved, and is a newer assessment available? boundary
2. Which current authority and protocol govern observation, reporting, sampling or intervention at this location? action

Kinds and varieties

Reported by the breadth pass; each item needs checking against its source before it becomes normative.

• North Pacific residents (fish-eating, matrilineal communities, including the Southern Resident stock)
• Bigg's / transient killer whales (North Pacific mammal-eaters)
• North Pacific offshore killer whales (outer-coast shark and fish eaters)
• North Atlantic Type 1 (generalist / fish-eating)
• North Atlantic Type 2 (mammal-eating)
• Antarctic Type A (open-water minke-whale hunters)
• Antarctic Type B (pack-ice seal hunters, including large B and small Gerlache B)
• Subantarctic Type D (blunt-snouted, rare; Antarctic Type C / Ross Sea fish-eaters are a further field form)

1. Which of these kinds and varieties hold for the sense of Orcinus orca this model covers, and on what evidence? provenance

Identifiers and schemes

Reported by the breadth pass; each item needs checking against its source before it becomes normative.

• Linnaean binomial (original combination) - Delphinus orca Linnaeus, 1758 - Type locality given as European seas; later transferred to Orcinus Fitzinger, 1860.
• Accepted binomial - Orcinus orca (Linnaeus, 1758) - No widely accepted living subspecies; ecotypes are informal.
• Wikidata - Q26843 - Item for the species, not for an individual or a captive display animal.
• NCBI Taxonomy - 9733 - Taxid for the species; genome and barcode records hang off this node.
• ITIS TSN - 180469 - North American integrated checklist.
• WoRMS AphiaID - 137187 - Authoritative marine taxonomic record.
• IUCN Red List species number - 15421 - Global assessment; regional and DPS listings use other instruments.
• GBIF taxonKey - 2436436 - Occurrence backbone usage for the species; confirm against the current GBIF backbone if citing counts.

1. Which of these identifiers and schemes hold for the sense of Orcinus orca this model covers, and on what evidence? provenance

Standards and regulation

Reported by the breadth pass; each item needs checking against its source before it becomes normative.

• IUCN Red List of Threatened Species - global Data Deficient (2017), IUCN SSC Cetacean Specialist Group, because ecotype taxonomy is unresolved.
• CITES Appendix II (CITES Secretariat) - international commercial trade in specimens is controlled; all cetaceans are listed unless a stricter appendix applies.
• Convention on the Conservation of Migratory Species of Wild Animals, Appendix II (UNEP/CMS) - range-state cooperation, not a take ban by itself.
• United States Marine Mammal Protection Act 1972 (NOAA Fisheries) - take, import and harassment rules for all stocks in U.S. waters.
• United States Endangered Species Act - Southern Resident distinct population segment listed Endangered (NMFS, 2005); other U.S. stocks are not ESA-listed.
• Canada Species at Risk Act / COSEWIC designatable units - Southern Residents Endangered; Northern Residents, West Coast transients and offshores assessed at risk separately from the global species.
• IWC Scientific Committee (International Whaling Commission) - research and bycatch advice; orcas are odontocetes and sit awkwardly relative to the large-whale moratorium.
• National vessel-approach rules (e.g. U.S. and Canadian Salish Sea distances for Southern Residents) - operational regulation of watching, not of the taxon name.

1. Which of these standards and regulation hold for the sense of Orcinus orca this model covers, and on what evidence? provenance

Real-world use

Reported by the breadth pass; each item needs checking against its source before it becomes normative.

• Encountered as a free-ranging apex predator in coastal and pelagic waters of all oceans, including high latitudes and some enclosed seas.
• Photo-identified and catalogued as named matrilines and communities (e.g. Center for Whale Research J/K/L pods; DFO Northern Resident catalogue), which is how managers count them.
• Target of commercial and community whale-watching in the Salish Sea, Norway, Iceland, New Zealand, Patagonia and the Antarctic Peninsula.
• Historically live-captured for oceanarium display; several jurisdictions now restrict or ban captive orcas, so the display animal is a declining, legally distinct use of the same taxon.
• Cultural being and clan emblem in several Pacific Northwest Indigenous legal orders and in Inuit and Māori naming, independent of the Linnaean species.
• Limited directed take and fisheries depredation conflict (longline and catch-robbing) in a few regions; not a global meat commodity.
• Since about 2020, a small Iberian population has repeatedly disabled yacht rudders, which is an interaction with vessels, not a fishery.

1. Which of these real-world use hold for the sense of Orcinus orca this model covers, and on what evidence? provenance

Typical measurements

Reported by the breadth pass; each item needs checking against its source before it becomes normative.

• adult male total length - 6-9 - m
• adult female total length - 5-7.5 - m
• adult male body mass - 3600-6600 - kg
• adult female body mass - 2500-4000 - kg
• newborn length - 2.0-2.5 - m
• adult male dorsal-fin height - 1.0-1.8 - m
• gestation - 15-18 - month
• female longevity in the wild - 50-80+ - year

1. Which of these typical measurements hold for the sense of Orcinus orca this model covers, and on what evidence? provenance

Failure modes and hazards

Reported by the breadth pass; each item needs checking against its source before it becomes normative.

• Treating the Linnaean species as the management unit hides endangered ecotypes (Southern Residents) inside a global Data Deficient listing.
• Prey collapse, especially Chinook salmon for Southern Residents, drives nutritional stress and missed pregnancies.
• Persistent organic pollutants (PCBs, PBDEs) biomagnify in mammal-eating forms and are linked to reproductive failure and immune suppression.
• Oil spills can delete whole matrilines; the AT1 transients declined sharply after the Exxon Valdez spill.
• Chronic vessel noise and close approaches reduce foraging time in boat-dense habitat.
• Live-capture and long-term captivity produce stereotypy, reduced lifespan relative to wild females, and rare fatal attacks on trainers; these are hazards of the display use, not of the wild taxon.
• Entanglement and, less often, ship strike.
• Depredation on fisheries and, in the Strait of Gibraltar, repeated ramming of yacht rudders create human-orca conflict without implying a general wild threat to people.
• Wild attacks on humans are exceedingly rare; captivity is the setting in which serious human injury has been documented.

1. Which of these failure modes and hazards hold for the sense of Orcinus orca this model covers, and on what evidence? provenance

Regional variation

Reported by the breadth pass; each item needs checking against its source before it becomes normative.

• English splits 'killer whale' (older, still official in U.S. and Canadian recovery documents) from 'orca' (now the usual public name); both name the same taxon.
• North Pacific three-ecotype practice (resident / Bigg's / offshore) does not map onto Antarctic Types A-D or onto North Atlantic Types 1 and 2.
• Legal status is local: Southern Residents are Endangered in the U.S. and Canada, while the same binomial is Data Deficient globally and unlisted under ESA in most other U.S. waters.
• French épaulard, German Schwertwal, Japanese shachi, Inuktitut aarluk, and various Pacific Northwest Indigenous names are not synonyms of one another in cultural use even when they pick out the same animals.
• Antarctic Type C often shows a yellow diatom film that field workers use as a regional cue, not a taxonomic character.

1. Which of these regional variation hold for the sense of Orcinus orca this model covers, and on what evidence? provenance

Neighbouring kinds and how to tell them apart

Reported by the breadth pass; each item needs checking against its source before it becomes normative.

• false killer whale (Pseudorca crassidens) - Smaller, uniformly dark, no white eye patch or saddle; the shared 'killer' name is historical, not a field mark.
• pilot whales (Globicephala melas / G. macrorhynchus) - Bulbous melon, broad-based falcate fin, no white eye patch; often called 'blackfish' with orcas in older fishery English.
• pygmy killer whale (Feresa attenuata) - Far smaller (to about 2.6 m), rounded head, no tall triangular male fin or white saddle.
• Orcaella (Irrawaddy and snubfin dolphins) - Different genus; small, rounded-head coastal/river dolphins whose name only collides in print.
• an individual orca, a captive display animal, or orca as meat - The registry object is the species taxon: Red List and ESA status attach to populations/ecotypes, not to a single body, a park animal, or a product.
• great white shark (Carcharodon carcharias) - Analogous apex-predator role in some coastal systems; body plan, thermoregulation and taxonomy are unrelated, and orcas prey on white sharks.

1. Which of these neighbouring kinds and how to tell them apart hold for the sense of Orcinus orca this model covers, and on what evidence? provenance