Northern Right Whale Dolphin

Lissodelphis borealis

LCLeast Concern
Anim1749 - Flickr - NOAA Photo LibraryNorthern Right Whale Dolphin (Lissodelphis borealis)Northern right whale dolphin mid-leap in a low arc above gray water, slender finless black bodyThree northern right whale dolphins bow-riding beside a boat, finless dark backs visible through green water
Photo: Credit: NOAA NMFS. · Public domainAnim1749 - Flickr - NOAA Photo LibraryPhoto: Daniel Benák · CC BY 4.0Northern Right Whale Dolphin (Lissodelphis borealis)Photo: Rudyard · CC BY 4.0Northern right whale dolphin mid-leap in a low arc above gray water, slender finless black bodyPhoto: cello caruso-turiello · CC BY 4.0Three northern right whale dolphins bow-riding beside a boat, finless dark backs visible through green water

The northern right whale dolphin is one of the easiest dolphins in the world to identify at a distance: it has no dorsal fin at all, giving it a smooth, torpedo-like back unlike almost any other dolphin sharing US waters. It travels in tight groups far offshore, often alongside Pacific white-sided dolphins, and rarely comes close to shore. Nearly all US records come from California's outer waters, with sightings recorded in every month but concentrated most heavily in fall.

Range through the year

Where Northern Right Whale Dolphin is seen

Northern Right Whale Dolphin is recorded in 3 US states from 102 occurrence records, most heavily in California (98 records) and Washington (3).

Current range102 records · 3 states
AlabamaArizonaArkansasCalifornia · 98 records · view state pageColoradoConnecticutDelawareDistrict of ColumbiaFloridaGeorgiaIdahoIllinoisIndianaIowaKansasKentuckyLouisianaMaineMarylandMassachusettsMichiganMinnesotaMississippiMissouriMontanaNebraskaNevadaNew HampshireNew JerseyNew MexicoNew YorkNorth CarolinaNorth DakotaOhioOklahomaOregon · 1 recordsPennsylvaniaRhode IslandSouth CarolinaSouth DakotaTennesseeTexasUtahVermontVirginiaWashington · 3 recordsWest VirginiaWisconsinWyomingAlaskaAKHawaiiHIPuerto RicoPR
Occurrence data by state and month
Northern Right Whale Dolphin – occurrence records by US state and month (102 total across 3 states)
StateJanFebMarAprMayJunJulAugSepOctNovDecYear
California462141618282151198
Washington·1···1···1··3
Oregon·········1··1

Based on 207 georeferenced US records, 2000-2026. Shading is observation density (where people record sightings), not true abundance. Alaska, Hawaii & Puerto Rico shown as insets.

Explore by state

Northern Right Whale Dolphin across 1 state

Occurrence records, conservation status, and the places it turns up, state by state. Open a state for detail, or visit its full page.

  • CaliforniaNativeOccasional207 records

    State rankUnranked

    Notable placesSanta Monica Mountains National Recreation Area · Golden Gate National Recreation Area · Bolsa Chica Ecological Reserve · Año Nuevo State Reserve

    Countiesrecorded in 12

    Year-round in California, with recorded sightings peaking in March–June, with a smaller rise in October.

    Full California page →All California mammals →

IUCN Red List status

  1. LC
  2. NT
  3. VU
  4. EN
  5. CR
  6. EW
  7. EX

LC – Least Concern

Widespread and abundant; not at risk.

SizeNorthern Right Whale Dolphin beside a 1.8 m adult, drawn to scale
Created by potrace 1.16, written by Peter Selinger 2001-2019 Created by potrace 1.16, written by Peter Selinger 2001-2019
Body length
2–3.1 m6 ft 7 in–10 ft 2 in
Weight
60–115 kg132–254 lb

Silhouettes drawn to scale against a 1.8 m5 ft 11 in adult.

Elevation

From 129 georeferenced records, the Northern Right Whale Dolphin is recorded from sea levelsea level to 13 m43 ft, with half of sightings below sea levelsea level.

Each band shows the share of georeferenced sightings that fall within it. Records cluster where people live and hike, so low, populated elevations are over-represented. Read this as observation density, not true abundance.

Observation peakOctober203 records

Seasonality from research-grade observation dates across the US (203 records, all years). Reflects when the species is recorded, not a guarantee of presence.

Best encounter

Where and when to see a Northern Right Whale Dolphin

Your best chance: California, in October.

Where
CaliforniaCA
When
October
Trophic relationshipsFood web What a Northern Right Whale Dolphin eats, and what eats it.
Eaten by

Few natural predators as an adult

This speciesNorthern Right Whale Dolphin
Smallfin Gonate SquidBerryteuthis anonychusBoreal Clubhook SquidOnychoteuthis borealijaponicaMedusafishIcichthys lockingtoniBrokenline LanternfishLampanyctus jordaniPatchwork LanternfishNotoscopelus resplendensTail-light LanternfishLampadena urophaosPrickly LanternfishMyctophum asperumPacific SauryCololabis saira
Eats8

A sample of documented feeding relationships, filtered to species that also occur in the US. Diet and predators vary by region and season, and this is not a complete list, many animals eat, and are eaten by, more than what has been formally recorded here.

Life history

The Northern Right Whale Dolphin (60–115 kg132.3–253.5 lb) is a carnivore that first breeds around 10 years, and carries a 365-day gestation. Maximum recorded longevity is 42 years.

Life cycle

  1. Gestation1 years (≈12 months)
  2. Sexual maturity10 yr (female)
  3. Typical lifespan42 years
  4. Maximum recorded longevity42 years

Reproduction

Gestation
365days≈12 months
Litters / year
0.5littersabout one every 2 years
Age at first breeding
10years

Diet composition

Carnivore

By foraging composition: 60% fish, 40% invertebrates.

  • Fish60%
  • Invertebrates40%

Most active around the clock.

Typical values for the species, not local measurements. Maximum longevity is the longest lifespan on record; most individuals live far less.

Commonly confused with

Animals people sometimes mistake for the northern right whale dolphin, and how to tell them apart.

A dolphin without a dorsal fin

Its genus name, Lissodelphis, translates roughly to smooth dolphin, and the reference is literal. This species has no dorsal fin at all, just a smooth, unbroken back that sets it apart from every other dolphin along the US Pacific coast. It’s also fast and social, typically traveling in tight groups rather than alone, and often reported swimming alongside Pacific white-sided dolphins in mixed pods.

A deep-water diet

Recorded prey includes squid such as the smallfin gonate and boreal clubhook squid, along with mesopelagic fish like lanternfish and medusafish, plus Pacific saury. Nearly all of these live in deep water below the sunlit surface layer. That points to a dolphin that dives well beyond where most coastal species feed.

California’s offshore waters, recorded year-round

California accounts for nearly every confirmed US record of this species, adding up to several hundred sightings across more than a decade of data. Sightings turn up in every month of the year, without the sharp seasonal gap some other cetaceans show, though records rise somewhat in fall. Nearly every record sits right at the surface near the outer coast, the only place a deep-diving species like this is ever actually seen.

Reproduction and lifespan

Northern right whale dolphins reach maturity around age ten, carry a pregnancy for about a year, and typically give birth every other year. Wild individuals have been recorded living past 40, a solid lifespan for a mid-sized dolphin that spends its life far from shore.

Conservation

The IUCN lists the northern right whale dolphin as Least Concern. It faces no widespread documented threat. Its offshore habits do mean much of what’s known about the species comes from strandings and at-sea surveys rather than easy coastal observation.

Sources

  1. GBIF – Lissodelphis borealis
  2. Wikipedia – Northern right whale dolphin
  3. iNaturalist – Northern Right Whale Dolphin
  4. Wikidata – Northern right whale dolphin

Data & sources

The data and visualizations on this page draw on these open sources: