Common Bottlenose Dolphin (Tursiops truncatus)
MammalMarineToothed Whale
Two common bottlenose dolphins surfacing off São Miguel Island in the Azores.
Image: Jules Verne Times Two, CC BY-SA 4.0, via Wikimedia Commons.
Overview
The common bottlenose dolphin (Tursiops truncatus) is a large, robust dolphin of temperate and tropical waters of the Atlantic, Pacific and Indian Oceans, the Mediterranean and the Black Sea. In the western North Atlantic it is found in deeper water at the continental shelf break and beyond, while a separate species, Tamenend's bottlenose dolphin, lives in nearshore coastal and estuarine waters from New York to Florida.
It has a short, thick beak set off from the melon by a crease, a lower jaw that projects beyond the upper, 18–26 pairs of large teeth in each jaw and a tall, curved dorsal fin near the middle of the back. It is dark to light gray above, fading to white — sometimes pinkish — below, with a dark stripe from eye to flipper.
Size figures vary by account and population: lengths are given as 6 to 13 feet without age or sex, or as 244–381 cm for adult males and 228–366 cm for adult females, and weights as 300 to 1,400 pounds, or about 500 kg for adult males and 250 kg for adult females. Males are larger than females, and newborns measure 84–140 cm.
Habitat & Range
Common bottlenose dolphins use a wide variety of habitats: harbors, bays, gulfs, sounds, lagoons and estuaries, passes between bays and the sea, open shorelines and large estuarine rivers, as well as nearshore waters, deeper water over the continental shelf and the open ocean far offshore. One account focused on the British Isles says densities appear higher inshore, and in the Gulf of Mexico two forms, inshore and offshore, may occur and are thought to interact little.
They are usually found in water of 50 to 90 °F at the surface, are absent from polar waters and are generally not found beyond latitude 45° except around Britain and northern Europe. In U.S. waters they occur off the West Coast, around Hawaii, along the East Coast from Massachusetts to Florida, and through the Gulf of Mexico and the Caribbean.
Diet
The common bottlenose dolphin is an opportunistic feeder on fish, squid and crustaceans such as crabs and shrimp: by an account written before the coastal western North Atlantic form was treated as a separate species, inshore dolphins typically take fish and invertebrates near shore, while deep-water dolphins eat mainly squid and open-water fish. Prey is usually 5–30 cm long and is swallowed whole, head first, so that its spines do not catch in the throat. Estimates of daily intake differ, from 4.5–16 kg to about 18–36 kg.
Dolphins hunt alone or together, finding prey by listening or by echolocation. Groups have been observed herding fish into tight schools; dolphins may also trap fish against sandbars and seawalls, and they have been known to strand themselves on shore to catch prey.
Behavior
These dolphins are very social, living in fission–fusion societies in which groups often split up and come back together. Groups commonly number fewer than 20, with units of 2–15 more common than large groups in one account, but groups of several hundred occur and more than 1,000 have been recorded offshore. Groupings include nursery groups of mothers and calves, juvenile groups up to their mid-teens, and adult males living alone or, more often, in strongly bonded pairs.
They are active by day and by night. To rest, a dolphin slows down and rests one side of its brain at a time, staying conscious enough to breathe, often in a tight, slow-moving group. In the same older account, deep-water dolphins breathe every 1–2 minutes and inshore ones twice a minute, though dives of 4.5 minutes without a breath are known; active dolphins often slap the water with their flukes and leap.
Human Interaction & Conservation
Getting caught in fishing gear is one of the main threats: dolphins can become entangled, hooked or caught in commercial nets, traps and longlines. Injuries from anglers' rod-and-reel gear are increasing, especially in the southeastern United States, as dolphins take bait and catch, eat discarded fish or are illegally fed by people. The largest direct kills were in the Black Sea, where hunting apparently reduced local populations, and in the Gulf of Mexico oil development, heavy boat traffic and pollution also affect them.
Bottlenose dolphins are the dolphins most commonly held in captivity. In the United States the species is protected by the Marine Mammal Protection Act of 1972, and it is listed in Annexes II and IV of the EC Habitats Directive, among species in need of strict protection. IUCN's global assessment lists the common bottlenose dolphin as Least Concern (2019).
Reproduction & Life Cycle
After a gestation of about 12 months, a female gives birth to a single calf, with a peak of births in the warmer months — in Sarasota Bay, Florida, mostly from May to July. Calves nurse for about 18–20 months and generally stay with their mothers for 3 to 6 years, and females have given birth at up to 45 or 48 years of age; bottlenose dolphins likely undergo menopause.
Accounts differ on maturity and birth intervals. Females mature at 5–10 or 5–12 years — 8.5 years, predicted, in the Sarasota study — and males at 8–13 or 10–13 years, and a female calves every 2–3 years by one account, every 3 to 6 years by others, or every 3.5 years on average (range 1–10) in Sarasota Bay.
Common bottlenose dolphins can live at least 40 years: males typically 40–45 and females more than 50, some to 60 or more, although one database gives lower wild estimates of up to 39 years for males and 49 for females. In Sarasota Bay the estimated maximum life spans are 67 years for females and 52 for males; in captivity the longest recorded is 51.6 years, or 53 by another account.
Sourced facts
Each value below is traced to the specific reference that states it. Open a row's evidence to see the source, where to look in it, and how firmly it supports the value. Sources checked 2026-10-20.
| Fact | What the source states | Evidence |
|---|---|---|
| Distinguishing traits | Large, robust gray dolphin with a short, thick beak set off from the melon by a crease, a lower jaw projecting beyond the upper, and a tall, curved dorsal fin near mid-back. Dark to light gray above, fading to white, sometimes pinkish, below, with a dark eye-to-flipper stripe.Has 18–26 pairs of large teeth in each jaw. One account says bottlenose dolphins near shore are often lighter in color than those offshore, while treating western North Atlantic nearshore animals as a separate species; European animals tend to be browner than western Atlantic ones. | Matches source · NOAA Fisheries (U.S. National Oceanic and Atmospheric Administration), Animal Diversity Web (University of Michigan Museum of Zoology), Natural Science Research Laboratory, Museum of Texas Tech University (The Mammals of Texas, 7th edition, Schmidly and Bradley, University of Texas Press), Marine Life Information Network (MarLIN), Marine Biological Association of the UK, Naturalis Biodiversity Center (Marine Mammals species database, Linnaeus NG) — how we knowNOAA Fisheries (U.S. National Oceanic and Atmospheric Administration)
Animal Diversity Web (University of Michigan Museum of Zoology)
Natural Science Research Laboratory, Museum of Texas Tech University (The Mammals of Texas, 7th edition, Schmidly and Bradley, University of Texas Press)
Marine Life Information Network (MarLIN), Marine Biological Association of the UK
Naturalis Biodiversity Center (Marine Mammals species database, Linnaeus NG)
|
| Geographic range | Native to temperate and tropical waters of the Atlantic, Pacific and Indian Oceans and the Mediterranean Sea, and also found in the Black Sea. Absent from polar waters and generally not found beyond latitude 45° except around Britain and northern Europe.Usually in water of 50 to 90 °F at the surface. U.S. waters: off California, Oregon and Washington, Hawaii, the East Coast from Massachusetts to Florida, the Gulf of Mexico and the Caribbean. In the western North Atlantic it is found in deeper waters at the continental shelf break and beyond, while Tamenend's bottlenose dolphin is found in nearshore coastal and estuarine waters from New York to Florida. | Matches source · Animal Diversity Web (University of Michigan Museum of Zoology), NOAA Fisheries (U.S. National Oceanic and Atmospheric Administration), Marine Life Information Network (MarLIN), Marine Biological Association of the UK, Natural Science Research Laboratory, Museum of Texas Tech University (The Mammals of Texas, 7th edition, Schmidly and Bradley, University of Texas Press), Mammal Diversity Database (American Society of Mammalogists) — how we knowAnimal Diversity Web (University of Michigan Museum of Zoology)
NOAA Fisheries (U.S. National Oceanic and Atmospheric Administration)
Marine Life Information Network (MarLIN), Marine Biological Association of the UK
Natural Science Research Laboratory, Museum of Texas Tech University (The Mammals of Texas, 7th edition, Schmidly and Bradley, University of Texas Press)
Mammal Diversity Database (American Society of Mammalogists)
|
| Habitat | Coastal and oceanic waters: harbors, bays, gulfs, sounds, lagoons, estuaries, passes between bays and sea, open shorelines and large estuarine rivers, plus nearshore waters, deeper water over the continental shelf and the open ocean far offshore.In the Gulf of Mexico two forms may occur, inshore animals in shallow lagoons, bays and inlets and offshore populations in deeper water, and the two are thought to interact little. One account focused on the British Isles says densities appear higher inshore. It enters rivers (large estuarine rivers in one account) but, by another account, not fresh water. | Matches source · NOAA Fisheries (U.S. National Oceanic and Atmospheric Administration), Animal Diversity Web (University of Michigan Museum of Zoology), Natural Science Research Laboratory, Museum of Texas Tech University (The Mammals of Texas, 7th edition, Schmidly and Bradley, University of Texas Press), Marine Life Information Network (MarLIN), Marine Biological Association of the UK — how we knowNOAA Fisheries (U.S. National Oceanic and Atmospheric Administration)
Animal Diversity Web (University of Michigan Museum of Zoology)
Natural Science Research Laboratory, Museum of Texas Tech University (The Mammals of Texas, 7th edition, Schmidly and Bradley, University of Texas Press)
Marine Life Information Network (MarLIN), Marine Biological Association of the UK
|
| Diet | Opportunistic feeder on fish, squid and crustaceans such as crabs and shrimp: inshore dolphins typically take fish and invertebrates near shore, deep-water dolphins mainly squid and pelagic fish. Prey is usually 5–30 cm long and swallowed whole, head first. Daily intake estimates differ.sources disagreeFish are swallowed head first so their spines do not catch in the throat. Hunts alone or cooperatively: groups have been observed herding fish into tight schools; dolphins may also trap fish against sandbars and seawalls and have been known to strand themselves on shore to catch prey, which they locate by passive listening or echolocation. The inshore and deep-water contrast comes from an account written before the coastal western North Atlantic form was treated as a separate species. Texas prey includes mullet, catfish, speckled trout, menhaden, anchovies, sharks, rays, shrimp and eels. | Sources disagree · NOAA Fisheries (U.S. National Oceanic and Atmospheric Administration), Animal Diversity Web (University of Michigan Museum of Zoology), Natural Science Research Laboratory, Museum of Texas Tech University (The Mammals of Texas, 7th edition, Schmidly and Bradley, University of Texas Press), Naturalis Biodiversity Center (Marine Mammals species database, Linnaeus NG) — how we knowWhat each reading says
Daily food intake is 4.5–16 kg in one account, depending on body size and lactation, but about 18–36 kg of fish in another. NOAA Fisheries (U.S. National Oceanic and Atmospheric Administration)
Animal Diversity Web (University of Michigan Museum of Zoology)
Natural Science Research Laboratory, Museum of Texas Tech University (The Mammals of Texas, 7th edition, Schmidly and Bradley, University of Texas Press)
Naturalis Biodiversity Center (Marine Mammals species database, Linnaeus NG)
|
| Body size | Length is given as 6 to 13 feet (age and sex not stated); for adults as 244–381 cm in males and 228–366 cm in females; as up to 3.5 m total length for adults; or as up to about 4 m. Newborns measure 84–140 cm, usually about 1 m by another account.sources disagreeMales are larger than females. One account says bottlenose dolphins near shore are often smaller than those offshore, while treating western North Atlantic nearshore animals as a separate species; European animals tend to be larger than western Atlantic ones. A newborn is more than one-third as long as its mother. | Sources disagree · NOAA Fisheries (U.S. National Oceanic and Atmospheric Administration), Animal Diversity Web (University of Michigan Museum of Zoology), Natural Science Research Laboratory, Museum of Texas Tech University (The Mammals of Texas, 7th edition, Schmidly and Bradley, University of Texas Press), Marine Life Information Network (MarLIN), Marine Biological Association of the UK — how we knowWhat each reading says
Length figures are of different kinds and disagree: an unqualified range of 6 to 13 feet in one account; adult ranges of 244–381 cm for males and 228–366 cm for females in another; and maximums of 3.5 m total length in a Texas account and about 4 m in a British Isles reference. NOAA Fisheries (U.S. National Oceanic and Atmospheric Administration)
Animal Diversity Web (University of Michigan Museum of Zoology)
Natural Science Research Laboratory, Museum of Texas Tech University (The Mammals of Texas, 7th edition, Schmidly and Bradley, University of Texas Press)
Marine Life Information Network (MarLIN), Marine Biological Association of the UK
|
| Body mass | Mass is given as 300 to 1,400 pounds (age and sex not stated); for adults as 260–500 kg, averaging 400 kg, with females about 250 kg and males about 500 kg; or as an average of 200,000 g. Newborns weigh 14–20 kg, or 19,350 g on average.sources disagreeMales are heavier than females; one account suggests females spend energy on reaching sexual maturity earlier while males keep growing. | Sources disagree · NOAA Fisheries (U.S. National Oceanic and Atmospheric Administration), Animal Diversity Web (University of Michigan Museum of Zoology), AnAge: The Animal Ageing and Longevity Database (Human Ageing Genomic Resources) — how we knowWhat each reading says
Mass figures disagree: 300 to 1,400 pounds, age and sex not stated, in one account; 260–500 kg for adults, averaging 400 kg, in another, which also puts adult females at about 250 kg, below its own range; and an adult average of 200,000 g in a longevity database. NOAA Fisheries (U.S. National Oceanic and Atmospheric Administration)
Animal Diversity Web (University of Michigan Museum of Zoology)
AnAge: The Animal Ageing and Longevity Database (Human Ageing Genomic Resources)
|
| Lifespan | Can live at least 40 years: males typically about 40–45 years, females over 50 years, some to 60 years or more. Wild: estimated maximums of 67 years (females) and 52 years (males) in Sarasota Bay, Florida. Captivity: up to 51.6 years, or 53 years by another account.sources disagreeFemales reach greater ages than males. The Sarasota figures come from long-term study of 482 resident dolphins; dolphins estimated to be older than the oldest confirmed deaths disappeared rather than being found dead. | Sources disagree · NOAA Fisheries (U.S. National Oceanic and Atmospheric Administration), Animal Diversity Web (University of Michigan Museum of Zoology), AnAge: The Animal Ageing and Longevity Database (Human Ageing Genomic Resources), Frontiers in Marine Science (Wells et al. 2025; Sarasota Dolphin Research Program, Brookfield Zoo Chicago) — how we knowWhat each reading says
Maximum ages disagree: wild estimates of up to 39 years for males and 49 for females in one database, against estimated maximums of 52 and 67 years in the Sarasota Bay study; captive maximums are 51.6 years in that database and 53 years in another account, whose data panel also lists average lifespans of 25.0 and 35.0 years in the wild and 45 and 30.0 years in captivity. NOAA Fisheries (U.S. National Oceanic and Atmospheric Administration)
Animal Diversity Web (University of Michigan Museum of Zoology)
AnAge: The Animal Ageing and Longevity Database (Human Ageing Genomic Resources)
Frontiers in Marine Science (Wells et al. 2025; Sarasota Dolphin Research Program, Brookfield Zoo Chicago)
|
| Activity pattern | Active both by day and by night. Rests one side of the brain at a time while slowing down, staying conscious enough to breathe, often in tight, slow-moving groups. Deep-water dolphins breathe every 1–2 minutes, inshore ones twice a minute.The breathing-rate contrast comes from an account written before the coastal western North Atlantic form was treated as a separate species. Dives of 4.5 minutes without breathing are known, and one account gives about 7 minutes as the maximum time under water. When active, especially while feeding or socializing, it often slaps the water with its flukes and leaps. | Matches source · Animal Diversity Web (University of Michigan Museum of Zoology), NOAA Fisheries (U.S. National Oceanic and Atmospheric Administration), Marine Life Information Network (MarLIN), Marine Biological Association of the UK, Naturalis Biodiversity Center (Marine Mammals species database, Linnaeus NG) — how we knowAnimal Diversity Web (University of Michigan Museum of Zoology)
NOAA Fisheries (U.S. National Oceanic and Atmospheric Administration)
Marine Life Information Network (MarLIN), Marine Biological Association of the UK
Naturalis Biodiversity Center (Marine Mammals species database, Linnaeus NG)
|
| Social structure | Very social, living in fission-fusion societies in which groups often split up and rejoin. Groups commonly number fewer than 20, with units of 2–15 more common than large groups in one account, but groups of several hundred occur and over 1,000 have been recorded offshore. Mating is polygamous.Groupings include nursery groups of mothers and calves, juvenile groups of both sexes up to their mid-teens, and adult males living alone or, more often, in strongly bonded pairs. Some males form alliances to seek out estrous females. Group size tends to increase with water depth, and dolphins may also travel alone. | Matches source · NOAA Fisheries (U.S. National Oceanic and Atmospheric Administration), Animal Diversity Web (University of Michigan Museum of Zoology), Natural Science Research Laboratory, Museum of Texas Tech University (The Mammals of Texas, 7th edition, Schmidly and Bradley, University of Texas Press), Marine Life Information Network (MarLIN), Marine Biological Association of the UK — how we knowNOAA Fisheries (U.S. National Oceanic and Atmospheric Administration)
Animal Diversity Web (University of Michigan Museum of Zoology)
Natural Science Research Laboratory, Museum of Texas Tech University (The Mammals of Texas, 7th edition, Schmidly and Bradley, University of Texas Press)
Marine Life Information Network (MarLIN), Marine Biological Association of the UK
|
| Reproduction | A single calf is born after about 12 months' gestation, with a birth peak in warmer months. Calves nurse for about 18–20 months and generally stay with the mother for 3–6 years. Females have given birth at up to 45 or 48 years old. Maturity ages and birth intervals differ by account.sources disagreeGestation is given as 12.5 months in one study and as 365 days in a longevity database. In Sarasota Bay most calves are born in May–July, and males have sired calves at 10–43 years. Bottlenose dolphins likely undergo menopause. | Sources disagree · NOAA Fisheries (U.S. National Oceanic and Atmospheric Administration), Animal Diversity Web (University of Michigan Museum of Zoology), Natural Science Research Laboratory, Museum of Texas Tech University (The Mammals of Texas, 7th edition, Schmidly and Bradley, University of Texas Press), Frontiers in Marine Science (Wells et al. 2025; Sarasota Dolphin Research Program, Brookfield Zoo Chicago), AnAge: The Animal Ageing and Longevity Database (Human Ageing Genomic Resources) — how we knowWhat each reading says
Birth intervals: every 3 to 6 years in two accounts, every 2–3 years in a Texas account, an average of 3.5 years (range 1–10) in Sarasota Bay, and an average of 858 days in a longevity database. Sexual maturity: females at 5–10 years, 5–12 years, a predicted 8.5 years in Sarasota Bay or an average of 2,831 days; males at 8–13 years, 10–13 years, a predicted 10 years in Sarasota Bay or an average of 3,689 days. NOAA Fisheries (U.S. National Oceanic and Atmospheric Administration)
Animal Diversity Web (University of Michigan Museum of Zoology)
Natural Science Research Laboratory, Museum of Texas Tech University (The Mammals of Texas, 7th edition, Schmidly and Bradley, University of Texas Press)
Frontiers in Marine Science (Wells et al. 2025; Sarasota Dolphin Research Program, Brookfield Zoo Chicago)
AnAge: The Animal Ageing and Longevity Database (Human Ageing Genomic Resources)
|
| Human interaction | Bycatch is a main threat: dolphins can get entangled, hooked or caught in commercial nets, traps, longlines and anglers' rod-and-reel gear. Direct kills were largest in the Black Sea, where hunting apparently reduced local populations. Bottlenose dolphins are the most common captive dolphins.Illegal feeding and taking bait, catch and discards teach dolphins to link anglers with food; such gear injuries are increasing, especially in the southeastern U.S. In the Gulf of Mexico, oil development, boat traffic and pollution also affect them. Protected in U.S. waters by the Marine Mammal Protection Act of 1972 and listed in Annexes II and IV of the EC Habitats Directive, among species in need of strict protection. The captivity statement treats bottlenose dolphins as one species. No harm to people is known. | Matches source · NOAA Fisheries (U.S. National Oceanic and Atmospheric Administration), Animal Diversity Web (University of Michigan Museum of Zoology), Naturalis Biodiversity Center (Marine Mammals species database, Linnaeus NG), Natural Science Research Laboratory, Museum of Texas Tech University (The Mammals of Texas, 7th edition, Schmidly and Bradley, University of Texas Press), Marine Life Information Network (MarLIN), Marine Biological Association of the UK — how we knowNOAA Fisheries (U.S. National Oceanic and Atmospheric Administration)
Animal Diversity Web (University of Michigan Museum of Zoology)
Naturalis Biodiversity Center (Marine Mammals species database, Linnaeus NG)
Natural Science Research Laboratory, Museum of Texas Tech University (The Mammals of Texas, 7th edition, Schmidly and Bradley, University of Texas Press)
Marine Life Information Network (MarLIN), Marine Biological Association of the UK
|
| Conservation status | Least Concern (LC), global assessment, 2019 | Matches source · IUCN Red List of Threatened Species — how we knowIUCN Red List of Threatened Species
|
References for the facts above
- GovernmentNOAA Fisheries (U.S. National Oceanic and Atmospheric Administration)Supports: identification, range, habitat, diet, body size, body mass, lifespan, activity, social structure, reproduction, human interaction. Retrieved 2026-10-20.Limitations: Species page last updated 09/01/2026. Its biology text speaks of 'bottlenose dolphins' in general, while its Science tab says the nearshore coastal form of the western North Atlantic is a separate species (Tursiops erebennus), so some general statements may draw on that form; quick-fact figures are not tied to age, sex or population. Uses the U.S. name 'Gulf of America' for the Gulf of Mexico. Stock-status listings, viewing guidance and fishing tips are not used.
- UniversityAnimal Diversity Web (University of Michigan Museum of Zoology)Supports: identification, range, habitat, diet, body size, body mass, lifespan, activity, social structure, reproduction, human interaction. Retrieved 2026-10-20.Limitations: Student-authored account (Jenkins 2009, last updated 2009-07-12) citing 1991-2008 literature, written before Tursiops erebennus was described. Internal inconsistencies: adult females 'about 250 kg' against a mass range starting at 260 kg; a lifespan panel (entries credited to the Max Planck Institute for Demographic Research) with differing averages; a CITES panel showing both 'Appendix I' and 'No special status'. Its passages on sponge-carrying dolphins in Australia, South African prey and seasonal migration along the U.S. Atlantic coast are not used, as they may concern populations now assigned to T. aduncus or T. erebennus.
- UniversityNatural Science Research Laboratory, Museum of Texas Tech University (The Mammals of Texas, 7th edition, Schmidly and Bradley, University of Texas Press)Supports: identification, range, habitat, diet, body size, social structure, reproduction, human interaction. Retrieved 2026-10-20.Limitations: Texas- and Gulf of Mexico-focused book account (copyright 1994, 2004, 2016) without in-text references; its breeding season is inferred from females taken in Texas waters, and its birth interval and daily food intake differ from other accounts. Population estimates are not used.
- ReferenceMarine Life Information Network (MarLIN), Marine Biological Association of the UKSupports: identification, range, habitat, body size, activity, social structure, human interaction. Retrieved 2026-10-20.Limitations: Basic-information review (Avant 2008, marked 'not refereed', last updated 03/07/2008) focused on the British Isles and drawing on the 1994 FAO identification guide; its legal-protection notes date from 2008.
- ReferenceNaturalis Biodiversity Center (Marine Mammals species database, Linnaeus NG)Supports: identification (beak crease), diet (opportunistic feeding), activity (aerial behavior), human interaction (Black Sea hunting, captivity). Retrieved 2026-10-20.Limitations: Undated identification-guide text (IUCN status shown as 'Insufficiently known') that treats bottlenose dolphins as one widespread species, from before Tursiops aduncus and T. erebennus were separated. Its size, weight, ventral spotting, look-alike and two-form statements are therefore not used; only statements unaffected by that change are cited.
- ReferenceAnAge: The Animal Ageing and Longevity Database (Human Ageing Genomic Resources)Supports: lifespan, body mass, reproduction (life-history averages). Retrieved 2026-10-20.Limitations: Build 15 (03/07/2023). The 51.6-year captive maximum cites Weigl (2005), rated medium sample size and acceptable data quality; the wild estimates cite Nowak (1999); the life-history averages are not tied to a population.
- ReferenceFrontiers in Marine Science (Wells et al. 2025; Sarasota Dolphin Research Program, Brookfield Zoo Chicago)Supports: lifespan, reproduction. Retrieved 2026-10-20.Limitations: Peer-reviewed review article (10 February 2025) of the long-term study, running since 1970, of one resident community in Sarasota Bay on Florida's Gulf coast; its figures describe that population only. The 12.5-month gestation is cited from O'Brien and Robeck (2012).
- ReferenceMammal Diversity Database (American Society of Mammalogists)Supports: identity (accepted name, authorship, classification, synonyms, other common names); range (Black Sea). Retrieved 2026-10-20.Limitations: Taxonomic record. Its distribution line is an image caption from the ASM Mammal Images Library. Its summary gives the type locality as 'Scotland, UK', while its own name record places it in South Devon, England.
- ReferenceIUCN Red List of Threatened SpeciesSupports: The global Red List category and the year of the assessment. Retrieved 2026-10-20.Limitations: Read from the Red List export IUCN publishes to GBIF; iucnredlist.org itself does not answer automated reads. Categories are reassessed over time.
Frequently Asked Questions — Common Bottlenose Dolphin
How big do bottlenose dolphins get?
Lengths are given as 6 to 13 feet without age or sex, or as 244–381 cm for adult males and 228–366 cm for adult females, and weights as 300 to 1,400 pounds. Males are larger than females.
How long do bottlenose dolphins live?
They can live at least 40 years: males typically about 40–45 and females more than 50, though one database gives lower wild estimates. In a long-term Florida study, the estimated maximums are 67 years for females and 52 for males.
Do bottlenose dolphins sleep?
They rest one side of the brain at a time while slowing down, staying conscious enough to breathe, often in tight, slow-moving groups.
How big are bottlenose dolphin groups?
Usually fewer than 20, with units of 2–15 more common than large groups in one account, though groups of several hundred occur and over 1,000 have been recorded offshore. Groups often split up and come back together.
Sources and further reading
Authoritative wildlife references used for general educational context. Conservation status should always be verified against current IUCN Red List data. External links open in a new tab.
- GovernmentNOAA Fisheries (U.S. National Oceanic and Atmospheric Administration) — Common bottlenose dolphin species page — identification, range, habitat, diet, body size, body mass, lifespan, activity, social structure, reproduction, human interaction
- UniversityAnimal Diversity Web (University of Michigan Museum of Zoology) — Tursiops truncatus (common bottlenose dolphin) species account — identification, range, habitat, diet, body size, body mass, lifespan, activity, social structure, reproduction, human interaction
- UniversityNatural Science Research Laboratory, Museum of Texas Tech University (The Mammals of Texas, 7th edition, Schmidly and Bradley, University of Texas Press) — Tursiops truncatus, The Mammals of Texas — identification, range, habitat, diet, body size, social structure, reproduction, human interaction
- ReferenceMarine Life Information Network (MarLIN), Marine Biological Association of the UK — Bottlenose dolphin, Marine Life Information Network — identification, range, habitat, body size, activity, social structure, human interaction
- ReferenceNaturalis Biodiversity Center (Marine Mammals species database, Linnaeus NG) — Common bottlenose dolphin, Marine Mammals species database — identification (beak crease), diet (opportunistic feeding), activity (aerial behavior), human interaction (Black Sea hunting, captivity)
- ReferenceAnAge: The Animal Ageing and Longevity Database (Human Ageing Genomic Resources) — Tursiops truncatus longevity entry — lifespan, body mass, reproduction (life-history averages)
- ReferenceFrontiers in Marine Science (Wells et al. 2025; Sarasota Dolphin Research Program, Brookfield Zoo Chicago) — Wells et al. 2025, the Sarasota Dolphin Research Program — lifespan, reproduction
- ReferenceMammal Diversity Database (American Society of Mammalogists) — Tursiops truncatus taxonomic record — identity (accepted name, authorship, classification, synonyms, other common names); range (Black Sea)
- ReferenceIntegrated Taxonomic Information System (ITIS) — Tursiops truncatus, TSN 180426 — identity cross-check: valid name, TSN 180426, synonym, four subspecies, class Mammalia
- ReferenceSociety for Marine Mammalogy, Committee on Taxonomy (List of Marine Mammal Species and Subspecies) — List of marine mammal species and subspecies — identity cross-check: the three Tursiops species and four T. truncatus subspecies
- ReferenceIUCN Red List — Tursiops truncatus assessment — The global Red List category and the year of the assessment