Globicephala melas

INFORMATION AND CHARACTERISTICS.

The Long-finned pilot whale is a cetacean member of the Delphinidae family, and one of the largest members of this group. Although it is commonly called “whale,” it is not a whale of the suborder Mysticeti. However, this colloquial name comes from its size and behavior.

The first word of its scientific name means something like “balloon head” as the Latin word “globus” means “balloon or ball” and “cephalas” means “head.”

Order: Cetacea
Family: Delphinidae
Genus: Globicephala

HOW DO THEY LOOK? PHYSICAL CHARACTERISTICS.

Morphology.
It is a relatively large animal with a robust body. It has a head with a bulbous forehead product of the bulging melon. Its beak is very short, and the long and curved line of the mouth gives it a face of a perpetual smile. The pectoral flippers are very long and correspond to a fifth of the total length of its body.

Weight and size.
The female is about 5.8 meters long. There is sexual dimorphism consisting of a bigger growth of the male, which reaches 7.6 meters in length. The female has a body mass of about 1,300 kilograms while the male weighs up to 2,300 kilos.

Skin Coloration.
The skin has a dark gray or black color in the upper dorsal area. The lower ventral region has a long, light gray, anchor-shaped patch that starts from the chest and ends around the genital slits. Behind the dorsal fin lies a small, light, saddle-shaped patch.

Physical characteristics.
It is a little difficult to distinguish this species from the short-finned pilot whale (Globicephala macrorhynchus) except for the length of the pectoral flippers which are larger in Globicephala melas than those of its relative.

WHERE DO THEY LIVE? DISTRIBUTION AND HABITAT.

The Long-finned pilot whale is distributed in the temperate and sub-polar zones of the southern hemisphere and the northern hemisphere and is absent from the tropical areas and the regions near the equator. In the North Atlantic is present in coastal waters and deep waters that include the Mediterranean, Barents and the North Seas and the Gulf of St. Lawrence. It is presumed extinct in the northern Pacific Ocean, but the western part may still be populated. Northern Scotland, Ireland, and Great Britain also have this dolphin.

In the southern hemisphere, it extends as far as the Antarctic Convergence at latitude 68° S in the south part of the Atlantic and Pacific Oceans, mainly near Australia and New Zealand.

Countries and regions whose waters are home to the Long-finned pilot whale are Canada, Denmark, United States, United Kingdom, Greenland, New Zealand, Australia, South Africa, Spain, Sweden, Libya, Italy, Ireland, Iceland, Argentina, Belgium, France, Germany, Falkland Islands, Portugal and Isle of Man.

Their habitat is variable. Some individuals seem to prefer staying close to the coasts while others are always in high seas. The areas where they dwell have high ridges or are on the edge of the continental shelf. The temperature of the waters that this dolphin inhabits is between 0° and 25° Celsius.

WHAT DO THEY EAT? DIET AND EATING HABITS.

The Long-finned pilot whale maintains a diet strictly carnivorous, in its menu excel fish like herring, cod, mackerel, turbot, dogfish and Hake, and cephalopods like the squids of the genus Gonatus and the species Todarodes sagittatus. Populations living in the northeast areas of the Atlantic Ocean eat mainly squid.

A Long-finned pilot whale consumes about 34 kilograms of food per day. Their favorite time to hunt is during the night. They do it submerging 200-600 meters deep to detect prey with the help of its senses, mainly echolocation.

It does not have a good reputation among the fishermen since it takes advantage of the moments in which the boats catch fish to obtain food the easy way.

HOW DO THEY BEHAVE? BEHAVIOR.

Like most dolphins, the Long-finned pilot whale is a very sociable species that form groups of 20-100 and up to 1,000 individuals or more. It seems that family groups are more delimited and not so fluid, that is, there are not many movements between groups and they can stay in their natal pod until all their life.

The family groups are composed of breeding females with inbreeding relationship, their offspring and some males that are not the fathers of their offspring. This behavior suggests a temporary membership to mate with the available females. The social ties are incredibly strong, and some believe that this is the reason for the massive stranding on the beaches: if the theory is correct, the members of a herd follow the one or those who stranded first.

Clicks, whistles, and pulsed sounds are standard in their communication processes.

HOW DO THEY REPRODUCE? MATING AND REPRODUCTION.

The polygamy of the Long-finned pilot whale is evident when a male goes to a pod different from his own in search of a receptive female to mate. The male reaches sexual maturity at around 12 years of age and females approximately at six years.

The courtship process is not very “kind,” on the contrary, the male exhibits an aggressive behavior consisting of blows with his melon to his partner’s melon. If it is successful then it mates, this can happen during any time of the year but more frequently in spring and summer.

15 or 16 months after mating, the female gives birth to 1 offspring of 1.2 to 2 meters in length which is the subject of exclusive maternal care for at least two years.

WHAT IS THEIR CONSERVATION STATUS? THREATS AND CONSERVATION.

Conservation Status: “Data Deficient.”

While humans keep destroying nature, species like the Long-finned pilot whale fear for their survival on Earth. Since the nineteenth century, this and other cetaceans were hunted in the waters of Newfoundland, Greenland, Denmark, Iceland, Norway, Scotland and other countries for their meat, fat, and oil. Over time, overfishing led to the gradual disappearance of the Long-finned pilot whale in the North Atlantic.

Nowadays the practice no longer has the same importance that once but is still realized in the Faroe Islands. Direct hunting has ceded its position as the leading threat to the species to bycatch, but other dangers menace this cetacean: the contamination of its habitat with chemical substances and heavy metals as well as the strandings that occur when fishing boats lead the Long-finned pilot whale towards the beaches.

The Red List of the International Union for the Conservation of Nature (IUCN) does not have enough data to assess its conservation status. In this regard, the UK Biodiversity Action Plan considers the protection of the species to be of paramount importance, and the Wildlife and Field Act 1981 declares the illegality of its capture, killing or any other activity that could be harmful to the life of whales and dolphins in the waters of the United Kingdom.

Conservation efforts should include ensuring the protection of the species from the entanglement they suffer in several kinds of fishing nets.

 

 

References

Mediterranean Marine Mammal Ecology and Conservation. Academic Press, 2016.

William F. Perrin, Bernd Würsig, J.G.M. ‘Hans’ Thewissen. Encyclopedia of Marine Mammals. Academic Press, 2009. Page 847.

http://www.cms.int/reports/small_cetaceans/data/G_melas/g_melas.htm

http://www.fisheries.noaa.gov/pr/species/mammals/whales/long-finned-pilot-whale.html

 

 

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