The 2020 biennial Commission meeting of the IWC will be held at the Grand Bernardin Resort, Portoroz, Slovenia
The 2021 meeting of the IWC Scientific Committee will be held in Bled, Slovenia
Sperm whales are the largest toothed cetacean. The size of most large baleen whales, they actually have teeth on their bottom jaw, used to grasp large squid or fish, unlike other large whales that filter smaller denser prey through their baleen. Almost mythical creatures, sperm whales were historically feared and revered in cultures around the world. The famous 19th century novel, Moby Dick, featured a sperm whale, and was based on the experiences of ‘Yankee whalers’ that roamed the world’s oceans hunting whales from small open boats in the 1800’s. Though not the largest species of whale, it does have the largest head and the largest brain of any animal on the planet; can dive deeper than almost any other marine mammal; and lives in a stable and complex matrilineal society similar to that of elephants. Sperm whales are usually found in deep oceanic waters, but can be observed closer to shore around islands or areas where underwater canyons or a narrow continental shelf provide deep water nearshore habitat.
Sperm whales are found in deep open waters, or around islands and coastal areas with deep canyons or very narrow continental shelves. Only males tend to be observed closer to the poles beyond approximately 40° S or 40° N1,2.
Sperm whales are native or seasonally present in the following countries and territories: Albania; Albania; Algeria; Angola; Antarctica; Antigua and Barbuda; Argentina; Australia; Bahamas; Bangladesh; Barbados; Belgium; Belize; Benin; Bonaire, Sint Eustatius and Saba; Brazil; Brunei Darussalam; Cameroon; Canada; Cape Verde; Chile; China; Colombia; Comoros; Costa Rica; Croatia; Curaçao; Cyprus; Denmark; Djibouti; Dominica; Dominican Republic; Ecuador; Egypt; El Salvador; Equatorial Guinea; Falkland Islands (Malvinas); Faroe Islands; Fiji; France; Gabon; Gambia; Ghana; Gibraltar; Greece; Greenland; Grenada; Guatemala; Guinea; Guinea-Bissau; Guyana; Haiti; Honduras; Iceland; India; Indonesia; Iran, Islamic Republic of; Ireland; Israel; Italy; Jamaica; Japan; Kenya; Kiribati; Korea, Democratic People's Republic of; Korea, Republic of; Lebanon; Liberia; Libya; Madagascar; Malaysia; Maldives; Malta; Marshall Islands; Mauritania; Mauritius; Mexico; Micronesia, Federated States of ; Monaco; Morocco; Mozambique; Namibia; Nauru; Netherlands; New Zealand; Nicaragua; Nigeria; Niue; Norway; Oman; Pakistan; Palau; Panama; Papua New Guinea; Peru; Philippines; Portugal; Russian Federation; Saint Helena, Ascension and Tristan da Cunha; Saint Kitts and Nevis; Saint Lucia; Saint Martin; Saint Vincent and the Grenadines; Samoa; Sao Tomé and Principe; Senegal; Seychelles; Sierra Leone; Singapore; Slovenia; Solomon Islands; Somalia; South Africa; Spain; Sri Lanka; Suriname; Syrian Arab Republic; Taiwan, Province of China; Tanzania, United Republic of; Thailand; Timor-Leste; Togo; Tonga; Trinidad and Tobago; Tunisia; Turkey; Tuvalu; United Kingdom; United States; Uruguay; Vanuatu; Venezuela, Bolivarian Republic of; Vietnam; Yemen
Sperm whales generally feed at depth in search of their preferred prey which consists of a variety of squid species, including the giant squid, Architeuthis. Female sperm whales almost exclusively eat squid while males have been documented to prey on bottom dwelling fish, including sharks, rays, cod and hake1. Sperm whales typically dive to an average depth of 800 meters for 50 minutes in search of food. Their bodies are uniquely adapted for this deep diving, with features such as high concentrations of the oxygen-carrying protein, myoglobin, in their muscles3, and a collapsible rib cage that allows their lungs to be compressed during deep dives.
Sperm whales form highly stable social groups based around related females and their offspring. These groups tend to live in open ocean areas, and are occasionally visited by males who range widely across the oceans. Calves are born after a 14-16 month gestation period, and stay with their mothers for many years. A calf will start to eat solid foods by the age of 1 year, but may continue suckling for several more years until the next calf is born. Young males will leave their female family unit when 4-21 years old, and will often join a ‘bachelor herd’ with other males of approximately the same age and size. These bachelor herds are observed in colder waters toward the poles. Females, however, stay with their family unit of 4-21 individuals and help to care for young in the group until they are mature enough to have their own calves. Like killer whales, they are one of the only mammal species other than humans, in which females continue to live and play a role in family/social groups after they have stopped producing calves. Fully mature males return to the warmer waters where the females are found in order to mate, sometimes spending only a few minutes or hours with a group before moving on again1,4.
Individual sperm whales can be recognised over time through crenulations and scarring on their dorsal fins and tail flukes. These photos are used to monitor individuals’ movements over time, estimate local population size and understand the social structure and population dynamics of the groups that are studied5-7.
Genetic sampling and the use of tags to monitor whales’ diving behaviour have been very important for understanding of sperm whale behaviour and populations 8-10 . More information about research techniques used to study whales and dolphins can be found here.
Killer whales have been observed attacking sperm whale pods, and large sharks are also thought to be potential predators of calves. Sperm whales in some parts of the world have a unique response to attacks, gathering into a ‘marguerite’ or wagon wheel formation – in which all members of the group position themselves with their heads in the centre and their tails facing outward like the spokes of a wheel. They then fend off attack by slashing their tails back and forth. Sometimes a vulnerable calf or injured whale is positioned at the centre of the formation1,11.
Sperm whales face a number of threats today, including entanglement in fishing gear12-14, ingestion of fishing gear and marine debris15,16, and ship strikes17-22. The latter is thought to be one of the main drivers of sperm whale population decline in the Mediterranean18,20,21, and a major threat to survival of sperm whales in the Canary islands17,19.
Sperm whales were historically heavily hunted, and today are globally designated as Vulnerable on the IUCN Red List of Threatened Species2. The genetically distinct Mediterranean subpopulation, however, is considered Endangered, due to the fact that there are estimated to be fewer than 2,500 individuals and the persistent threats of ship strikes and entanglement throughout the area23. Sperm whales are listed on Appendix 1 of the Convention on Migratory Species (CMS).
Please see the IWC Whalewatching Handbook