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| Subspecies: | Unknown |
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| Est. World Population: | |
| CITES Status: | NOT LISTED |
| IUCN Status: | Least Concern |
| U.S. ESA Status: | NOT LISTED |
| Body Length: | |
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| Jumping Ability: | (Horizontal) |
| Life Span: | in the Wild |
| Life Span: | in Captivity |
| Sexual Maturity: | (Females) |
| Sexual Maturity: | (Males) |
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The species is the most tropical of the Mesoplodon species, and its distribution in Europe is consequently limited to the southernmost part of the assessment region. Like all beaked whales, it inhabits deep, oceanic waters over and seaward of the continental slope (Allen et al. 2011, Baird et al. 2011, Claridge et al. 2015), including topographic features such as the edges of seamounts and canyons (Fernandez et al. 2021). Around volcanic archipelagos, where deep water occurs close to shore, the species can occur within a few kilometres of the shoreline (Baird et al. 2011). In the Canary Islands, sightings occurred at depths of 25 to 1,600 m at Tenerife, with average depths of around 450 m (Carrillo 2003, Carrillo et al. 2010). At La Gomera, sightings occurred at depths of 100–850 m, with a mean of 320 m (Ritter and Brederlau 1999).
Blainville’s Beaked Whales are not known to undertake marked seasonal migrations. Rather, photo-identification and tagging work have evidenced long-term, multi-year, site fidelity of the species in different geographic regions (McSweeney et al. 2007, Claridge et al. 2015), including in Europe (Dinas et al. 2017, Suárez 2018, Badenas et al. 2022). Sightings and strandings in the Canary Islands (Ritter and Brederlau 1999, Carrillo et al. 2010, Martín et al. 2011) occur throughout the year.
The species predates mesopelagic and bathypelagic cephalopods and fish, which it is thought to capture by suction feeding (Allen et al. 2011). In Europe, the stomach contents of a whale stranded in Wales (UK) contained the squid Histioteuthis reversa (Herman et al. 1994), while an animal in the Canary Islands contained fish of the families Gadidae and Myctophidae, and beaks from the cephalopod taxa Octopoteuthis sicula, H. reversa, H. meleagroteuthis, Histioteuthis Type A and Taonius pavo (Santos et al. 2007). To capture their prey, Blainville’s Beaked Whales undertake deep foraging dives that regularly exceed 800 m depth (Tyack et al. 2006, Baird et al. 2008, Claridge et al. 2015), with maximums of at least 1,888 m depth and over 60 min duration (Claridge et al. 2015). In Europe, nine whales tagged in the Canary Islands had foraging dives with mean depths of 616 to 1,003 m, and mean durations of 41 to 58 min (Arranz et al. 2011). The maximum depth of a dive recorded in the Canary Islands was 1,311 m (Arranz et al. 2011). Between deep foraging dives, the whales undertake a series of shallow dives and spend time resting near the surface (Baird et al. 2008, Arranz et al. 2011). Diving behaviour in groups tends to be synchronous, perhaps as a strategy to avoid predators such as killer whales (Orcinus orca: Aguilar de Soto 2020).
Globally, the species occurs in small groups of 1 to 11 animals (Claridge 2013, McSweeney et al. 2007), with mean group sizes recorded in Europe of 4.6 animals in Tenerife (Canary Islands: Carrillo 2003), 3.4 animals at La Gomera (Canary Islands: Ritter and Brederlau 1999), and 3.7 animals in Madeira (Alves et al. 2018). Groups generally comprise a mature male with several adult females and their young (Ritter and Brederlau 1999, McSweeney et al. 2007, Claridge 2013, Badenas et al. 2022). Calves have been observed in March, August and November at Tenerife (Carrillo et al. 2010), and have been seen nursing in the waters around La Gomera (Ritter and Brederlau 1999).
Global
This species has more diagnostic morphological features than many other mesoplodonts, and consequently it is more easily identified at sea. It is the most widespread Mesoplodon species globally, and occurs in oceanic habitat across the warm temperate to tropical regions of all oceans, including some semi-enclosed seas such as the Gulf of Mexico and the Sea of Japan (MacLeod et al. 2006, Allen et al. 2011). Within the North Atlantic, it is distributed from the equator northwards to at least Nova Scotia in the western Atlantic (McKenzie 1940) and the U.K. of Great Britain and Northern Ireland in the eastern Atlantic (Herman et al. 1994).
European
Given its apparent preference for (sub)tropical water temperatures, the species is only regularly observed in the southernmost part of the European assessment area. It is the most commonly recorded mesoplodont in the Canary Islands and in Madeira, where sightings are regularly documented and long-term studies of the species’ distribution and ecology are underway (e.g., Ritter and Brederlau 1999, Carrillo et al. 2010, Dinis et al. 2017, Suárez 2018, Badenas et al. 2022).
Further north in Europe, the species is documented almost entirely by occasional strandings, including in the Strait of Gibraltar (Bellido et al. 2008), mainland Portugal (Sequeira et al. 1992, 1996), the Azores (Silva et al. 2014), Spain (Bellido et al. 2008), and the Biscay coast of France (Réseau National Échouages, www.observatoire-pelagis.cnrs.fr). Sightings appear to be increasing in the Azores (Rui Prieto pers. comm.). It is considered a vagrant in the Mediterranean Sea, where it is documented from a single stranding in Catalonia, Spain (ACCOBAMS 2021).
The few records from areas further north of the Bay of Biscay are likely to be extralimital. These include a pregnant female that stranded in 2005 on the North Sea coast of the Netherlands (Camphuysen et al. 2008), a stranding in Wales (UK) in 1993 (Herman et al. 1994, Law et al. 1997), and one stranding from Iceland (MacLeod et al. 2006). The latter is considered likely to be extralimital, given the preference of the species for warm temperate and tropical waters. A single sighting has also been reported in Irish waters, comprising two animals near the Rockall Plateau in 2016 (Richardson et al. 2018). However, the species has not been recorded amongst 132 documented beaked whale strandings in Ireland (Rogan and Hernandez-Milian 2011), suggesting that its occurrence there is rare.
The Mediterranean population is listed on Appendix II (strictly protected species) of the Convention on the Conservation of European Wildlife and Natural Habitats (Bern Convention); elsewhere in Europe it is included on Appendix III (protected species).
It is included with all cetaceans on Annex IV Council Directive 92/43/EEC on the Conservation of Natural Habitats and of Wild Fauna and Flora (the Habitats Directive) as a species requiring strict protection across its entire natural range within the EU. All Mesoplodon species are included in Appendix II (species that are not necessarily threatened with extinction but may become so unless trade is closely controlled) of the Convention on International Trade in Endangered Species (CITES), which requires an export permit or re-export certificate for international trade.
It is included in two regional management agreements in Europe, comprising the Agreement on the Conservation of Cetaceans of the Black Sea, Mediterranean Sea and contiguous Atlantic area (ACCOBAMS) where it is listed on Annex 1, and the Agreement on the Conservation of Small Cetaceans of the Baltic, North East Atlantic, Irish and North Seas (ASCOBANS). These agreements aim to maintain the favourable conservation status of cetacean species within their defined areas, managing threats and working towards the long-term sustainability of populations.