Marine Creature: Cuvier’s beaked whale (Ziphius cavirostris)
Kindly compiled by CIMA Research Foundation
The Cuvier’s beaked whale is an odontocete and belongs to the family of beaked whales. Ziphius cavirostris is the only species within the genus Ziphius. Main identifying features for this species are cigar shaped body, a small triangular dorsal fin, set two thirds of the way down their back, and a well-defined beak, even though less pronounced than other beaked whale species.
Cuvier’s beaked whale can be distinguished from other beaked whales by the single pair of short (up to 6cm long) conical teeth at the tip of the lower jaw. Usually these teeth erupt from the jaw only in adult males, while they might not be visible in immature and adult females.
They are brown to light grey in colour, depending on the age. Calves and immature are usually brown, while adult appear paler, also due to the presence of scarring caused by intra-specific competition, parasites and other injuries. Dark patches around the eyes are common in adult animals.
They are usually sighted alone or in small groups (composed by 2 to 12 individuals).
Cuvier’s beaked whale has the largest geographical range of all the beaked whales, being found in almost all sub-polar, temperate, sub-tropical and tropical waters. However, they have never been observed in high latitude polar regions. Within the global range beaked whale occurrence has been linked to depth, generally being found in waters over 1000m deep and in regions with a complex seabed topography, particularly slopes, canyons, seamounts, escarpments and oceanic islands. Usually it is not found in shallow water areas, less than 200m.
Cuvier’s beaked whale is perhaps the most common beaked whale with more reported sightings and strandings than any other beaked whale. There are currently no worldwide abundance estimates for this species, but it is likely to be over 100,000 animals.
It is the only beaked whale species commonly sighted in the Mediterranean Sea. As other cetacean species in the Mediterranean Sea, the population inhabiting the basin is quite likely to be genetically isolated. As of yet there are no abundance estimates for the Mediterranean areas. Within the Mediterranean Sea, the Ligurian Sea and especially the Genoa Canyon is recognised as a hot-spot for this species.
1. Cuvier’s beaked whales are excellent divers, with maximum dive depth and duration having been reliably recorded to depths of over 1, 800m and for up to 85mins. Spending up to 80% of their life underwater at depth, operating close to their physiological limits.
2. Cuvier in 1823 first described the species having found only the skull. Given the thickness of the bone, he believed to be a fossil and an extinct species.
- Food: Deep water squid but also some fish and crustacean species.
- Lifespan: Unconfirmed
- Size: Maximum length is between 6m to 7m and weight 2,500 – 3,500Kg, with no significant difference between the sexes.
Cuvier’s beaked whale reaches sexual maturity between 5.3 – 5.8m in length. Females might have one calf every 2 – 3 years following a year’s gestation. Newborns are between 2.5 – 2.7m in length and 250 – 300 kg in weight. Calving happens most often in the spring months.
Feeding mainly on deep water squid species, Cuvier’s beaked whales use echolocation to locate their prey, like other toothed whales or odontocetes. They produce on average ~ 2 usual clicks per second and when they close in on prey they produce ~ 250 echolocation clicks per second. This sequence is also called a “buzz”. The buzz coupled with the dive profile indicates that foraging occurs during the deep dives. It has been estimated that they attempt to catch on average 30 prey items per dive.
The lack of dentation, a pair of expandable throat grooves and a large piston like tongue suggest that these animals are suction feeders.
Cuvier’s beaked whales suffer from many of the threats that affect all whale species, such as incidental by-catch in fishing gears, heavy metal and pollution intoxication and the effect of global climate change. However, recently there has been a growing concern about beaked whales due to several mass strandings reported worldwide. Forty-one mass strandings of Cuvier’s beaked whales have been reported. Furthermore, these likely represent only a small proportion of all dead animals, as some that die offshore may not wash ashore, some that strand may not remain on the beach for more than one tidal cycle and observation effort can vary by location.
Some of mass strandings were concurrent with naval manoeuvres and the use of active sonar: this has raised concerns that certain sounds from sonar could result in the death or injury of beaked whales. For these reasons, in 2004 the Parties to the UNEP CMS Agreement on the Conservation of Cetaceans of the Black Sea, Mediterranean Sea and Contiguous Atlantic Area (ACCOBAMS) adopted a resolution recommending that human activities introducing high-intensity noise in the marine environment be avoided in the areas where high concentrations of beaked whales may occur.
The Cuvier’s beaked whale is nowadays listed as Least Concern in the IUCN red list. Nevertheless, as for all other Mediterranean cetacean species, the conservation status of the Mediterranean subpopulation has been estimated separately. Cuvier’s beaked whale in the Mediterranean is listed as Data Deficient.
The species is still protected under the marine mammal protection act of 1972 and under the EU habitats directive of 1982. In the Mediterranean, the ACCOBAMS agreement and the institution of the Pelagos Sanctuary are both aimed to increase the conservation status of the species.
How can people help?
Reporting any stranded animals to the relevant authorities as soon as possible.
Any photos that you manage to take of these animals, plus where and when you took them can be forwarded onto to researchers that can be used to help assess the population size and structure of these animals.
Best places in the world to see these creatures:
Given the beaked whale’s preference for deep water and certain seabed topographies, like slopes and canyons, the best place to see these whales is where these features lie close to land. Examples of known hot-spots for this species include: Mediterranean Sea, Hawaii, Bahamas (es. Tongue of the ocean), Bay of Biscay, Azores and Canary Islands. In the Mediterranean Sea the species is mainly sighted Ligurian Sea, Alboran Sea and Northern Thyrrenain Sea. For ethical reviews and rating system for whale watching trips to see Cuvier’s beaked whales visit www.planetwhale.com
Profile: CIMA Research Foundation
Organisation: CIMA Research Foundation – International Centre on Environmental Monitoring
Year(s) Founded: 2007
CIMA Research Foundation is a non-profit research organization committed to the promotion and support of scientific research, technological development and training within the fields of hydro-geological risk reduction, forest fires and monitoring of the marine environment.
Founded in 2007 as the outgrowth of the pre-existing Inter-University Centre for Research in Environmental Monitoring, CIMA Research Foundation founding institutions are the Italian Civil Protection Department, the University of Genoa, the Regione Liguria (Government of Liguria Region), and the Provincia di Savona (Administration of Savona Province).
The observation of ecosystem dynamics and especially the monitoring of cetacean as bio-indicators are essential research areas for CIMA Research Foundation for finding effective tools for the conservation and management of the marine ecosystem.
Importance of work
The Ziphius project aims to acquire the information needed for the assessment of the conservation status of Cuvier’s beaked whale in the Mediterranean sea. This is a long-term research project, started in 2004 thanks to the collaboration of the University of Genoa and to the whale watching company BluWest (2004-2007)
- assess population abundance in Northwestern Mediterranean sea and point out population trends;
- describe population structure;
- define residency, site fidelity and home range of Ligurian individuals;
- describe and map Cuvier’s beaked whale habitat;
- point out distribution hot-spots in order to help in a better management of anthropic activities
Nowadays CIMA Research Foundation holds one of the biggest photo-id database of this species.