Although they can be found nearly anywhere in deep oceanic waters, Cuvier’s Beaked Whale is an oceanic species often associated with steep slope habitat with a marked preference for submarine canyons and escarpments (Azzellino et al. 2011, Breen et al. 2020, D’Amico et al. 2003, MacLeod 2005, Podestá et al. 2016, Cañadas et al. 2017, Kiszka et al. 2007, Robbins et al. 2022). It is rarely found close to mainland shores, except in submarine canyons or in areas where the continental shelf is narrow and coastal waters are deep (Heyning 1989, 2002, Moulins et al. 2007). The species is known to occur around many oceanic islands (Freitas et al. 2020) mostly within the 1000-2000 m isobaths (Silva et al. 2014). In the Mediterranean, the species preferred depth range is normally comprised between approximately 500 and 1,500m, (Cañadas and Notarbartolo di Sciara 2018), although it can also be occasionally found in offshore, deep waters covering abyssal plains (Frantzis et al. 2003).

Cuvier’s Beaked Whales are largely found in “hotspots” areas such as in the North Atlantic, the Bay of Biscay (particularly around the Santander Canyon) (Kiszka et al. 2007, Rogan et al. 2007), South Eastern Rockall Slope edge (Berrow et al. 2018, Breen et al 2020, Kowarski et al. 2018) and in the Mediterranean, the Alborán Sea, the northern Ligurian Sea (including the Genoa Canyon area); the northern Tyrrhenian Sea (including the Caprera Canyon) and the Hellenic Trench to the west of Cyprus, especially around Anaximander Seamount (ACCOBAMS 2021). In these locations, characterized by complex topography, the animals are regularly seen indicating the species’ strong preference for specific habitats (Cañadas et al. 2005, Podestà et al. 2016). There is no information available about the movements of Cuvier’s Beaked Whales between hotspots. However, Giorli and Neuheimer (2016) proposed that beaked whales may seasonally migrate to optimise prey capture, evidenced by the increased strandings of Cuvier’s Beaked Whales along select parts of the Irish coast during spring and summer. An increase in the frequency of unusual mortality events is reported in the North Sea region (comprising data from Belgium, Germany, the Netherlands and the eastern UK) and the Atlantic/Celtic region (comprising the western seaboard of the UK and France and Ireland) between 1990 and 2020 with the highest number registered in 2018 (Dolman et al. 2021). 50% of the overall beaked whale strandings are Cuvier’s Beaked Whale.

Cuvier’s Beaked Whale is mainly teuthophagic and, like all beaked whales, appears to prefer deep waters for feeding. Field research conducted with data logging tags (Johnson and Tyack, 2003) characterized these animals as extreme divers since they can routinely dive deeper than 1 km for an hour or more (Baird et al. 2006; Tyack et al. 2006). Dive profiles were characterized by a series of shallow dives, lasting no more than 22 min and reaching a maximum depth of 425 m, followed by deep dives to a maximum depth of 1888 m with a maximum duration of 85 min (Tyack et al. 2006, Zimmer et al. 2005, 2007).

Although few stomach contents have been examined, they appear to feed mostly on deep-sea squid, but also sometimes take fish and some crustaceans (MacLeod et al. 2003). The most common prey species in the Mediterranean are from the family Histioteuthidae (largely Histioteuthys bonnellii and H. reversa), which are oceanic and meso- or bathypelagic, inhabiting depths of around 1,000 m, with a preference for escarpments (Cañadas and Notarbartolo di Sciara 2018).

They are found mostly in small groups of 2-7, but are not uncommonly seen alone. Mean group size is fairly constant across the whole Mediterranean basin where data have been collected, ranging from 1.6 to 2.5 individuals, but was seen to be 4 in the Ligurian Sea (Cañadas and Notarbartolo di Sciara 2018).

Cuvier's Beaked Whales may have the most extensive range of any beaked whale species (Heyning 1989, 2002). They are widely distributed in offshore waters with the exception of shallow water areas and very high-latitude polar regions. The species range covers most of the European marine waters. Cuvier’s Beaked Whales is present year-round in the deep oceanic waters of the southern Bay of Biscay, a deep-water gulf with complex topography and hydrography, situated between the southern coast of Brittany, the west coast of France and the northern Spanish coast (Kiszka et al. 2007, Robbins et al. 2022). Cuvier’s Beaked Whales are reported along the Rockall Trough shelf edge and canyons area (Berrow et al. 2018, Kowarski et al. 2018, Breen et al. 2020). Further north, it is relatively rare, with a small number of sightings around the British Isles (Dolman et al. 2021). Strandings of Cuvier’s Beaked Whales occurred almost on the Atlantic coasts of the UK and in Ireland with a seasonal increase of sightings in late autumn off north-west Porcupine Bank (McLeod et al. 2004, Dolman et al. 2010). In the Canary Islands, the waters off El Hierro Island host an important concentration of Cuvier´s Beaked Whales year-round (Reyes Suárez 2018). Sightings and strandings are reported around the Azores and Madeira Archipelagos (Freitas et al. 2004, Freitas et al. 2012, Freitas et al. 2020, Silva et al. 2014). Cuvier's Beaked Whale is the only species of beaked whale regularly found in the Mediterranean Sea. Cuvier’s Beaked Whales inhabit both the western and eastern basins of the Mediterranean Sea (Podesta et al. 2016). Much of the current knowledge of this species in the Mediterranean has come from stranded animals. Strandings have been reported in Albania, Algeria, Croatia, Egypt, France, Greece, Israel, Italy, Malta, Spain, and Türkiye (Podestà et al. 2006). According to the predicted densities from spatial modelling (Cañadas et al. 2017), there are six high-density areas in the Mediterranean: Ligurian Sea, Alborán Sea, Hellenic Trench, northern Ionian Sea, southern Adriatic Sea, and the northern Tyrrhenian Sea (Cañadas and Notarbartolo 2018).

It is absent from the Baltic and the Black seas and the Turkish Strait System.

The Cuvier’s Beaked Whale is listed in Appendix II of the Convention on International Trade in Endangered Species (CITES). 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. The species is also listed in Appendix II (strictly protected species) of the Convention on the Conservation of European Wildlife and Natural Habitats (Bern Convention). The Mediterranean population is listed on Appendix I (Endangered migratory species) of the Convention on the Conservation of Migratory Species of Wild Animals (Bonn Convention, 1979) and in Annex II of the Barcelona Convention for the Protection of the Marine Environment and the Coastal Region of the Mediterranean SPA/BD.

As a result of the concerns regarding cetacean exposure to anthropogenic noise resulting from military activity, the Parties to Agreement on the Conservation of Cetaceans of the Black Sea, Mediterranean Sea and contiguous Atlantic area (ACCOBAMS), during their 5th Meeting (Tangiers, 2013) resolved that, during naval exercises using sonar or underwater explosions, there should be absolute avoidance within a 50 nautical mile buffer zone around all areas that have been designated as ‘Areas of Special Concern for Beaked Whales’ in the Mediterranean Sea (ACCOBAMS 2013).

The 25th Meeting of the Agreement on the Conservation of Small Cetaceans of the Baltic, North East Atlantic, Irish and North Seas (ASCOBANS) Advisory Committee recommended that applying the precautionary principle is of greater importance with beaked whales, as compared with other small cetaceans, given the likelihood of small population sizes in beaked whales and the overwhelming evidence that military activities can have severe impacts on these taxa, and acknowledging the difficulties encountered in gaining reliable information (ASCOBANS 2019).
In 2004 a moratorium on mid-frequency active sonar was established by the Spanish Government around the Canary Islands and there have not been any additional atypical mass strandings since. This clearly shows that such bans can be effective.

A Specially Protected Area of Mediterranean Importance under the Barcelona Convention has been proposed for the northern half of the Alborán Sea and Gulf of Vera in southern Spain (Cañadas et al. 2005). The Pelagos Sanctuary for Mediterranean marine mammals encompasses the Ligurian Sea Cuvier’s beaked whale hotspot and the northern portion of the Caprera Canyon hotspot providing some level of protection to the species from illegal driftnet fishing in the Sanctuary that is lower compared to other areas, and that the use of naval sonar is presumably avoided in the Sanctuary. Elsewhere in the region, Cuvier’s Beaked Whales are devoid of effective protection (ACCOBAMS 2021).

Three Important Marine Mammal Areas (IMMAs) were identified in the Mediterranean which included Ziphius cavirostris as qualifying species: The Alborán Deep IMMA, the “Western Ligurian Sea and Genoa Canyon” IMMA, and the “Hellenic Trench” IMMA (https://www.marinemammalhabitat.org/imma-eatlas/). These include three of the major Cuvier’s Beaked Whale hotspots in the region.