In the 1800s Arctic whalers returned with tales of a ‘unicorn of the sea’—a mysterious tusked whale that scientists later named the narwhal while its white, vocal cousin, the beluga, was already well-known to Indigenous hunters.
Comparing narwhals vs beluga whales matters because these two toothed whales shape Arctic food webs, support Inuit and other Indigenous communities, and face different conservation challenges as the ice and industry change. Though both species share Arctic waters and a toothed-whale lineage, narwhals and beluga whales differ in six clear ways: external anatomy, size and color, vocal behavior, social organization, habitat preferences, and conservation status. The article walks through those six differences with examples, numbers, and what they mean for conservation and people.
Physical and Anatomical Differences
These outward traits are the quickest way to tell the two species apart and tie directly to biology and human uses. Below are the two most visible anatomical contrasts.
1. Tusk presence and function
Only narwhals grow the long, spiralized upper left canine known as the tusk; most males have one, and some females occasionally do too. The tusk commonly reaches up to approximately 2.7 m (9 ft) in length.
Anatomical and histological studies show dense innervation along the tusk’s pulp and canal system, and recent research demonstrates the tusk can sense changes in water chemistry and temperature—so it acts as a sensory organ as well as a male sexual signal. Museums often label tusks as both cultural and scientific artifacts, and Inuit carvers historically used narwhal tusks in trade and art.
Beluga whales lack any external tusk; their teeth are all inside the mouth and visible only when feeding or in museum skulls. At sea, a protruding tusk makes narwhals easy to identify from a distance, while belugas are recognized by other cues (color and head shape).
2. Size, coloration, and skull shape
Adult belugas usually appear white and have a rounded, bulbous forehead or “melon.” Beluga body length typically ranges from about 3 to 5 m. Narwhals are mottled gray and dark when young and often lighten with age; they average roughly 3.5 to 5.5 m in length.
Belugas have unfused cervical vertebrae, giving them a flexible neck that helps them turn and search for prey in shallow bays and river mouths. Narwhals have a less mobile neck and a slimmer melon relative to body size, traits linked to their offshore, deep-foraging lifestyle.
Beluga lifespans are commonly estimated at about 35–50 years. Field guides, museum specimen records, and Inuit knowledge all help with identification: white belugas are unmistakable in summer estuaries, while a narwhal’s tusk or mottled pattern is the giveaway offshore.
Behavioral and Acoustic Differences
Both species echolocate and make social calls, but their acoustic repertoires and social behaviors diverge in ways that affect research and subsistence use. Below are the vocal and social contrasts.
3. Vocalizations and echolocation
Belugas earned the nickname “canaries of the sea” because of a wide range of whistles, chirps, and clicks, often concentrated in shallow, social settings. Their vocalizations occupy high-frequency bands—many calls span from a few kHz up into tens of kHz—making them easy to detect in coastal passive acoustic monitoring.
Narwhal calls tend to be lower-frequency and include monosyllabic pulsed calls and clicks that often link to deep-foraging bouts. Tagging and spectrogram studies (e.g., recordings from Hudson Bay and Greenland) show narwhal calling, and click rates, are associated with dives and prey-searching at depth.
Those acoustic differences matter: passive acoustic monitoring programs use species-specific signatures to tell which whale is present, informing management and Indigenous hunting safety. Lower-frequency offshore calls can travel further under ice, while high-frequency beluga calls attenuate faster in shallow water.
4. Social structure, group size, and migration
Belugas commonly form stable coastal pods that range from tens to low hundreds of individuals and show strong site fidelity to estuaries and bays. Some seasonal coastal aggregations can reach several hundred animals, and a few stocks (like Cook Inlet) consist of much smaller, resident populations.
Narwhals tend to form larger seasonal aggregations offshore; summer groups off Greenland and in northern Hudson Bay can number in the hundreds to thousands during open-water months. They undertake longer migrations tied to sea-ice cycles and use leads and polynyas as movement corridors.
These social and migratory differences affect vulnerability. Coastal, resident belugas face local pressures like small-boat disturbance and pollution, while narwhals’ large offshore aggregations can be more exposed to industrial seismic activity and changing ice routes that disrupt migrations.
Habitat, Ecology, and Conservation
Where these whales live and what they eat drive how we manage them. The two species overlap across Arctic waters but use different parts of that seascape and thus face distinct threats and policy needs.
5. Range, habitat preferences, and diving behavior
Narwhals are strongly ice-associated and spend much of their year offshore in pack-ice and deep-water areas. Tagging studies have recorded narwhal dives to depths of up to around 1,500 m during foraging trips.
Belugas frequent shallow coastal areas, estuaries, and river mouths—habitats that offer benthic and nearshore prey. Typical beluga dives are much shallower, usually in the hundreds of meters or less, matching diets of bottom-dwelling fish and invertebrates.
These habitat choices change exposure: narwhals face threats linked to ice-loss and offshore industry, whereas belugas often encounter coastal contaminants, vessel traffic, and freshwater changes—each context requiring different management approaches.
6. Conservation status and human threats
Both species include populations with different conservation statuses. For example, the Cook Inlet beluga stock is listed as endangered with a population estimate of about 279 individuals (NOAA), illustrating how a coastal, resident group can be critically small.
Narwhal populations are generally monitored with concern: ice loss, increased shipping, seismic surveys, and expanding commercial activity in the Arctic raise risks. Some Greenland stocks are managed with harvest quotas informed by Fisheries and Oceans Canada and local agreements.
Authoritative assessments (IUCN, NOAA, national agencies) show variation across stocks rather than a single status for each species. Management implications are clear: small, resident beluga populations need strict local protections, while narwhal conservation focuses on sea-ice integrity, noise, and regulated offshore development.
Summary
Tusk vs no tusk: Narwhal males (and some females) grow a sensory tusk up to ~2.7 m; belugas lack an external tusk.
Appearance and size: Belugas turn white and have flexible necks (about 3–5 m); narwhals are mottled, often 3.5–5.5 m, and less neck-flexible.
Sound and behavior: Belugas are highly vocal in shallow waters; narwhals use lower-frequency calls tied to deep dives, sometimes reaching ~1,500 m.
Social and seasonal patterns: Beluga pods are often coastal and resident (tens to low hundreds); narwhal aggregations can number in the hundreds to thousands and migrate with the ice.
Conservation contrasts: Some beluga stocks (Cook Inlet ~279) are critically small; narwhals face growing offshore threats from ice loss and industrial activity—different threats, different management.
Protecting Arctic whales means protecting both coastal estuaries and offshore ice habitats, and following updates from IUCN, NOAA, and national agencies as research and management evolve.
