Species guide
Sowerby's beaked whale
Mesoplodon bidens
At a glance
Conservation, taxonomy and Madeira records reviewed . Review sources.
- Global IUCN conservation status
- Least Concern — assessment published .
Global extinction risk is separate from sighting frequency in Madeira.
- Identification
- Slender body, usually grey with a paler underside.
- Small, slightly curved dorsal fin set well back on the body.
- Size
- Adult length: Approximately 4.5–5.5 m.
- Recorded occurrence in Madeira
- Reported on local trips, including August 2024.
- Madeira records and season
- No dependable seasonal window established by the cited records.
Identification and size summarize profile notes updated . Local records are past observations, not a prediction of sightings.
Read the identification notes ↓- Taxonomic authority
- (Sowerby, 1804)
- Family
- Ziphiidae
- Cetacean group
- Odontoceti
Sightings in Madeira
Our operator reports list Sowerby's beaked whale in June 2022, July 2023 and August 2024. These reports document local observations but do not establish a regular sighting season or independently verify every identification.
ID characteristics
- Slender body, usually grey with a paler underside.
- Small, slightly curved dorsal fin set well back on the body.
- Long, narrow beak and a gently rounded forehead.
- Adult males have a pair of teeth that project from the lower jaw, roughly midway along the beak. In females and juveniles, the teeth remain hidden beneath the gums.
This species can be difficult to distinguish from other beaked whales at sea.
Surface behaviour
An elusive whale that can be difficult to approach and observe. The beak may emerge at a steep angle when the animal surfaces to breathe.
Distribution
Found in the North Atlantic, mainly in deep temperate and subarctic waters. Its range includes waters around Madeira and the Azores, extending north towards Iceland and Norway and across to eastern North America.
Social behaviour
Seen alone or in small groups, commonly of three to ten individuals.
Diet
Mainly small, deep-water fish, with squid also taken. In a study of animals stranded in the Azores, fish accounted for more than 99% of prey items.
Biometrics
Adult length: Approximately 4.5–5.5 m.
Adult weight: Approximately 1–1.3 tonnes.
Blow
Small and inconspicuous; often difficult to see at sea.
Conservation status
The global classification does not mean the species is common around Madeira. Its abundance and population trends remain poorly known. Threats include entanglement in fishing gear and disturbance from underwater noise.
Common names in other languages
ENG - North Atlantic beaked whale
GER - Sowerby-Zweizahnwal, Nordsee-Schnabelwal, Flosser
FRA - Baleine de Sowerby, Mésoplodon de Sowerby
ESP - Zifio de Sowerby, Zifio del Atlántico norte, Ballena de pico de Sowerby
SWE - Sowerbys näbbval
DAN - Almindelig næbhval, næbhval
ITA - Mesoplodonte di Sowerby
NED - Gewone spitssnuitdolfijn, Noordzee-spitssnuitdolfijn
NOR - Nordspisskval, Nordspisshval, Sowerbys spisshval
POL - Wal dwuzębny, delfin Soverby’ego
POR - Baleia de bico de Sowerby, Baleia bicuda de Sowerby, Baleia de bico de garrafa
Sources
- NOAA Fisheries: Sowerby's beaked whale — identification, behaviour, distribution, weight and threats.
- COSEWIC assessment and status report (2019) — adult length and species biology.
- Pereira et al. (2011): Diet of mid-Atlantic Sowerby's beaked whales — diet recorded in the Azores.
- IUCN Cetacean Specialist Group: December 2020 Red List assessments — change from Data Deficient to Least Concern.
Review sources
Conservation, taxonomy, local occurrence and seasonality checked on . The assessment publication year is separate from this editorial review date. Identification, size, other biology notes and multilingual aliases are outside this review unless a specific source is cited alongside them.
- IUCN Red List: Mesoplodon bidens — global species assessment, published 2020.
- Society for Marine Mammalogy: species and subspecies list (April 2026) — Scientific names, authorities, families and English names. Mysticeti and Odontoceti are treated as unranked groups.
- IUCN SSC Cetacean Specialist Group: Red List status of cetaceans — Global species categories cross-checked against the specialist group's overview, updated October 2025. Regional and subpopulation assessments are separate.
- IUCN Cetacean Specialist Group: December 2020 assessments — Global beaked-whale assessments. Several changes from Data Deficient reflect revised guidance, not demonstrated recovery.
- Freitas et al. (2012): New records of cetacean species for Madeira Archipelago with an updated checklist — Table 1 and species accounts distinguish sightings, catches and strandings. Record totals and last-record dates describe evidence available through December 2012.
The linked trip reports document operator observations. They do not independently confirm every identification or measure population size, abundance or the probability of a sighting.