INFORMATION AND CHARACTERISTICS.

Although the common and scientific name of this toothed cetacean refers to the white color of its snout, they may or may not have the beak of this color.

The white-beaked dolphin is the largest member of the genus Lagenorhynchus, and it was one of the first dolphins of this genus to be scientifically recognized, back in 1846.

Order: Cetacea
Family: Delphinidae
Genus: Lagenorhynchus

HOW DO THEY LOOK? PHYSICAL CHARACTERISTICS.

Morphology.
It has a sturdy body, a short and thick beak and a narrow tail. It has a big and sickle-shaped dorsal fin just in the middle of its body.

Weight and size.
Adult individuals measure between 2.3 and 3.1 meters in length and weigh 180 to 354 kilograms. Males are slightly larger than females.

Skin Coloration.
It has a black or dark gray dorsal area. The sides usually have lighter stripes with different shades of light gray almost white. Its beak may exhibit a whitish color, but it can also be gray and even black.

Distinctive characteristics.
It has a white patch that starts just behind the dorsal fin and ends before the tail flukes.

WHERE DO THEY LIVE? DISTRIBUTION AND HABITAT.

The white-beaked dolphin inhabits the waters of the North Atlantic Ocean. In the western part of this ocean it dwells from the Strait of Davis to the south of Cape Cod (Massachusetts, United States) passing through the center and the west of Greenland; In the east of the ocean is distributed from Iceland to Portugal but in the north reaching as east as the Scandinavian peninsula. Its locations include the Barents Sea, the Baltic Sea, Ireland, Canada, the Irish Sea and the United Kingdom. It also resides in the west of the Mediterranean Sea.

It inhabits the cold subpolar waters of its distribution zone, in the continental shelf, along with the edge of this and in coastal waters; Mainly in waters whose depth does not exceed 200 meters.

WHAT DO THEY EAT? DIET AND EATING HABITS.

It feeds on a large variety of mesopelagic fish mainly those that group in schools, like the capelin, haddock, hake, herring and cod. It also consumes crustaceans and cephalopods (octopus and squid), like most dolphins.

This species performs hunting techniques cooperatively on the surface of the ocean. It sometimes associates with humpback whales (Megaptera novaeangliae), Fin whales (Balaenoptera physalus) and other dolphins, including those of the species Tursiops truncatus (bottlenose dolphin).

HOW DO THEY BEHAVE? BEHAVIOR

The White-beaked dolphins create social groups composed of 5 to 50 individuals (generally less than 30), but they occasionally form larger groups of up to 1,500 dolphins. There is little information on the social structure of this species, but the separation by age and sex can occur. They sometimes mix and associate with large species like fin whales and humpback whales, and other small cetaceans, especially in the feeding areas (Reeves et al. 2002). These gregarious dolphins often perform acrobatic jumps on the surface and frequently approach ships to ride the bow waves.

HOW DO THEY REPRODUCE? MATING AND REPRODUCTION.

The white-beaked dolphin reaches sexual maturity when it is between 7 and 13 years old or when they grow to a length of 2.4-2.5 meters. The gestation period lasts about 11 or 12 months. Subsequently, a single offspring is born in the summer (months of May to September) measuring about 1.1-1.2 meters long.

Additional information on the reproduction of this species is so far unknown.

WHAT IS THEIR CONSERVATION STATUS? THREATS AND CONSERVATION.

Conservation Status: “Least Concern.”

This species has been and still is hunted in the waters of the Faroe Islands, Iceland, Norway and Greenland, and even in Canada off the coast of Newfoundland, to obtain its oil and meat. Also, they are affected by the contamination of their habitats with heavy metals and organochlorines.

It is under protection by the ASCOBANS (Agreement on the Conservation of Small Cetaceans in the Baltic, North East Atlantic, Irish and North Seas) and in the Red List of the International Union for the Conservation of Nature, it appears as a species with a conservation status of “Least Concern.”

References

Jefferson, Webber, Pitman. Marine Mammals of the World: A Comprehensive Guide to Their Identification. Academic Press, 2015. Page 282.

William F. Perrin, Bernd Würsig, J.G.M. ‘Hans’ Thewissen. Encyclopedia of Marine Mammals. Academic Press, 2009. Page 1255.

http://www.cms.int/reports/small_cetaceans/data/l_albirostris/l_albirostris.htm

http://www.nmfs.noaa.gov/pr/species/mammals/cetaceans/whitebeakeddolphin.htm

INFORMATION AND CHARACTERISTICS.

This dolphin is one of two species of the genus Lissodelphis. It is a toothed cetacean found only in the southern hemisphere. Bernard Germain de LacépèdeIt described this species in 1804 based on a specimen he saw near the island of Tasmania.

PHYSICAL DESCRIPTION.

Morphology.
This dolphin has the thinnest body of all cetaceans. Its body, incredibly hydrodynamic, is similar to the one of the northern right whale dolphin (Lissodelphis borealis) with a slender shape, a short snout and lacking the dorsal fin. It has a tilted forehead instead of rounded like most species and pectoral flippers with a sickle shape.

Weight and size.
The adult dolphin measures 1.8-2.9 meters in length and weighs between 60 and 100 kilograms. The sexual dimorphism is very slight, being the male bigger than the female.

Order: Cetacea
Family: Delphinidae
Genus: Lissodelphis

Skin Coloration.
The body of this cetacean is bicolor. The dorsal area is black from the forehead to the tail lobes. The white color starts from the snout and continues to the belly and up to the middle of both sides. The pectoral flippers are usually gray, and some individuals exhibit small white patches on the head.

Distinctive characteristics.
Their coloring pattern and the lack of dorsal fin are the main distinguishing features. There may be confusion with the northern right whale dolphin because they have a similar appearance, but the difference between them lies in the fact that the sides of this dolphin are entirely black, and the snout is not white as the southern species. Besides, the distribution area of each species is far from each other.

WHERE DO THEY LIVE? DISTRIBUTION AND HABITAT.

It has a circumpolar distribution only in waters of the southern hemisphere, between the Antarctic Convergence and the Subtropical Convergence. Its limits are between latitudes 30° south and 65° south, being the north of Peru the northmost limit of its distribution.

It is present in countries such as Australia, Chile, Argentina, New Zealand, Uruguay, South Africa, Mozambique, and Peru.

It is a pelagic dolphin that prefers high seas and only approaches the coasts if the waters are deep on the edge of the continental shelf. The temperatures of their cold habitats range between 1° and 20° Celsius degrees.

WHAT DO THEY EAT? DIET AND EATING HABITS.

Studies of the stomach of specimens of this species report a carnivorous diet in which mesopelagic fish, crustaceans, and cephalopods have preponderance. Their preys commonly inhabit depths between 200 and 1,000 meters.

Given its thin and hydrodynamic body, most scientists think that this dolphin is quick and agile to capture its prey, but if it feeds on the surface or in lower layers of the water column, it is still unknown.

Some of its favorite prey are lanternfish (Myctophidae), bigeye tuna (Thunnus obesus), squid, shrimp and species of the family Euphausiacea, which includes several species of krill.

HOW DO THEY BEHAVE? BEHAVIOR

It is a highly gregarious species which the creation of pods influence its social and individual behavior. A pod of Lissodephis peronii is usually composed of more than 100 members and may have up to 1,000 members. However, the average number of dolphins in a group is around two hundred.

If a dolphin is alone without company, it shows a relative shyness and avoids the ships. On the other hand, if a dolphin is with its pod, it shows more activity and dynamism. They can jump and hit the water with their belly or tail and create disturbances on the surface of the ocean due to the massive number of individuals in the pods.

Pods usually submerge for more than 6 minutes, but a single dolphin only dives for a very short time, so it tends to surface every 10 seconds or so. When swimming slowly, it only keeps the spiracle and part of the head out of the water; this is usually done while resting or during periods of low activity.

To date, there is no significant data on the existence of migration patterns, although it is likely that during the spring and summer they move northwards.

HOW DO THEY REPRODUCE? MATING AND REPRODUCTION.

There is a lack of information about most of the breeding habits of the southern right whale dolphin, but research suggests that males reach sexual maturity when they have a length of 2.51 meters and females are sexually mature with an approximate length of 2.18-2.28 meters.

The birth season is not known although in winter and spring more calves are seen, so perhaps the births occur around those seasons.

A calf can measure 0.86 meters in length and weigh about 5 kilograms at birth. Its longevity is approximately 42 years in the wild.

WHAT IS THEIR CONSERVATION STATUS? THREATS AND CONSERVATION.

Conservation Status: Data Deficient.

It is true that there are more doubts than confirmed facts about this species. In fact, not even the International Union for Conservation of Nature (IUCN) has sufficient data to assess its conservation status which has a “Data deficient” classification due to the lack of information about the species.

However, this does not mean that the southern right whale dolphin is out of danger as this species has several threats, most of them derived from human activities. In Peru and Chile they have been caught for consumption, and in other regions, bycatch is common when these cetaceans become entangled in gillnets, particularly those trying to catch swordfish.

There are no specific conservation efforts for the Southern right whale Dolphin yet, but CITES has included it in Appendix II of endangered species where this organization lists the animals whose commercial trade must follow strict regulations.

References

Jefferson, Webber, Pitman. Marine Mammals of the World: A Comprehensive Guide to Their Identification. Academic Press, 2015. Page 306.

http://www.iucnredlist.org/details/12126/0

http://www.cms.int/reports/small_cetaceans/data/L_peronii/l_perronii.htm

http://www.fao.org/fishery/species/18218/en

Lagenorhynchus australis

INFORMATION AND CHARACTERISTICS.

The Peale’s dolphin or Black-chinned Dolphin are the common names used to call this toothed cetacean of the southern hemisphere. In English, its common name, Peale’s dolphin is in honor to the naturalist Titian Peale, who described the species in the year 1848.

It is the largest species of the genus Lagenorhynchus, although in recent years a closer relationship with the genus Cephalorhynchus was discovered, which could end in a new taxonomic classification for this species shortly.

Order: Cetacea
Family: Delphinidae
Genus: Lagenorhynchus

HOW DO THEY LOOK? PHYSICAL CHARACTERISTICS.

Morphology.
It is perhaps the most robust species of its genus but still conserves a body with a form of a torpedo. Its dorsal fin, pointed and curved, can reach up to 50 centimeters of height and its rounded pectoral flippers measure around 30 centimeters in length. It has a short beak; it is only about 5 cm long.

Weight and size.
There is a slight sexual dimorphism that produces greater dimensions in the case of males. An adult measures 2.18-2.20 meters in length while the females reach about 2.10 meters in length. The maximum size of an adult is 3.10 meters. They weight on average 115 kilograms.

Skin Coloration.
The color of its skin is remarkable and very striking. Black on the dorsum and white on the belly, this two-color pattern is interrupted by a thin white stripe that begins below the dorsal fin and widens as it extends backward. From the eyes to the middle of the sides there is a white area separated from the belly by a thin black band. The pectoral flippers and the dorsal fin are black.

Distinctive characteristics.
It is true that this species can easily be confused with the Dusky dolphin (Lagenorhynchus obscurus), but this dolphin has a dark face and a thin black band near the rib cage which makes it different.

WHERE DO THEY LIVE? DISTRIBUTION AND HABITAT.

This animal is endemic of the southern hemisphere, and they dwell between latitudes 30° south in the Pacific and 38° south in the Atlantic Ocean and 60° south where both oceans join, that is, in South American waters surrounding the southern tip of the continent. This distribution includes only Chile, Argentina, and the Falkland Islands; Around Tierra del Fuego, Cape Horn and the Strait of Magellan. Recently sightings of the species were reported near the Cook Islands, between Hawaii and New Zealand but this is unconfirmed data yet.

It is a coastal dolphin that inhabits seas with very shallow depths on the continental shelf. It dwells in the bays, inlets, canals, fjords and stay around the islands, on beds of seaweed and even on the sandbanks.

WHAT DO THEY EAT? DIET AND EATING HABITS.

The Peale’s dolphin does not mind feeding alone but usually hunts in groups. It has a carnivorous diet and eats large quantities of fish as well as crustaceans and cephalopods. The prey most consumed by this species are:

– Argentine red shrimp (Pleoticus muelleri).
– Squids of the species Loligo gahi and Illex argentinus.
– Argentine Hake (Merluccius hubbsi).
– Tadpole codling (Salilota australis).
– Patagonian grenadier (Macruronus magellanicus).
– Southern red octopus (Enteroctopus megalocyathus).
– Anchovy (Family Engraulidae).
– Herring (Genus Clupea).

It has a very varied diet. The feeding process begins with the formation of groups of 5 to 30 individuals who stay underwater for 10 seconds-1.5 minutes. They have a marked preference for searching algae beds. When they find prey, they surround it and begin to eat. If the victims are a school of fish, they spend time chasing, corraling and eating them in organized turns.

HOW DO THEY REPRODUCE? MATING AND REPRODUCTION.

The information about their reproductive habits is very scarce. What is known is that the female has one offspring per delivery and gives birth during the spring to autumn after a gestation period of 10 to 12 months.

When births are close, the mothers approach to areas close to the coast. There a calf is born with a length of approximately 0.9-1.25 meters, which swims next to its mother as soon as it leaves the belly. The offspring is cared for about 18 months or until it is two years old.

HOW DO THEY BEHAVE? BEHAVIOR

The pods of Peale’s dolphins have few members, between 2 and 20 individuals although there are groups as small as 2-4 or as large as 100 dolphins. These large groups, if created, are in turn segmented into smaller social clusters. They usually hunt by cooperation, but a hypothesis assumes that this happens only when there is abundant food.

They occasionally associate with other species of dolphins, especially the Commerson’s dolphin (Cephalorhynchus commersonii) and the Risso’s dolphin (Grampus griseus).

It is a shy dolphin that sometimes comes close to the boats but not often. From there you can see it jumping, riding the bow waves and splashing water with its tail.

No migration patterns are known, but southernmost individuals are believed to follow fish movements.

WHAT IS THEIR CONSERVATION STATUS? THREATS AND CONSERVATION.

Conservation Status: “Data Deficient.”

The Red List of the International Union for the Conservation of Nature does not have sufficient data to assess this species according to its state of conservation. However, since the 1970s it has been exploited to use parts of its body as bait for crabs and is not free of the danger that gillnets mean.

In addition to direct and incidental catch, contamination of their habitat with organochlorines endangers their health, as well as tourist rides that offer dolphin observations can disrupt their life underwater.

The Peale’s dolphin is in Appendix II of CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora), where the species whose trade requires strict regulation appear. Also, the Chilean government has implemented measures to reduce the use of dolphin meat as a crab bait, and because of this, it seems that the number of catches for this purpose has reduced.

References

http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.452.3889&rep=rep1&type=pdf

http://www.iucnredlist.org/details/11143/0

https://en.wikipedia.org/wiki/Peale%27s_dolphin

http://www.cms.int/reports/small_cetaceans/data/L_australis/L_australis.htm

http://www.arkive.org/peales-dolphin/lagenorhynchus-australis/

(Orcinus Orca)

INFORMATION AND CHARACTERISTICS.

Although it is commonly named “killer whale,” environmentalist are trying to change this name because there are two inaccuracies in it: it is not a whale, and much less a killer. The Orca is a toothed cetacean member of the genus Delphinidae, so it is the largest dolphin in the world.

Although it is also a powerful predator that even attacks sharks, it is not a human killer. Attacks have occurred but only from specimens in captivity victims of stress and confusion.

Order: Cetacea
Family: Delphinidae
Genus: Orcinus

HOW DO THEY LOOK? PHYSICAL CHARACTERISTICS.

Orcas are considered monotypic, that is, they belong to a single species although in recent years some scientists think that the smaller orcas of Antarctic waters are a subspecies. There are several ecotypes result of one of the largest distribution of all mammals, in fact, just after humans.

Weight and size.
Orcas exhibit sexual dimorphism since males are larger than females. Adult males reach a length of 6 to 8 meters and weigh about 6 tons; while females have a length about 5-7 meters and weigh about 3 to 4 tons. The maximum registered length in an orca is 9.8 meters.

Morphology.
It is a huge and bulky cetacean that has a shape similar to the other dolphin species. It has a strong skeleton and the skin covered with collagen fibers. Both genders have a round head with a big forehead and pectoral flippers similar to paddles. Its dorsal fin is also large: in males can measure up to 1.8 meters while that of females reaches between 70 and 80 centimeters and is more curved. The caudal fin has two flukes and measures 1.8 meters wide.

It has 10 centimeters long teeth covered with enamel; those in the front can lean forward when the orca holds a prey. Orcas have excellent senses of sight, hearing and touch.

It is the largest mammal predator and feeds on a wide variety of large or small animals.

Skin Coloration.
An Orca is easily recognizable by its black and white color pattern. The dorsal area is black but changes to white from the lower jaw passing through all the ventral part up to the anus. Above the eyes, it has a white patch. Its flippers are also black, and it has a gray saddle patch in the dorsal area just behind the dorsal fin. Orcas show this coloration pattern after one year of age.

Distinctive features.
The color pattern is unique to each specimen. Also, the gray patch behind the dorsal fin called “saddle” got this name because of its apparent resemblance to such supportive structure.

Orcas – Orcinus orca.

WHERE DO THEY LIVE? HABITAT AND DISTRIBUTION.

The orca distribution is incredibly broad, ranging from the polar waters to the equator in the open ocean or closed systems such as the Gulf of Mexico, the Gulf of California, the Persian Gulf, the Mediterranean Sea and the Red Sea. They are distributed in all the oceans of the world although they have a preference for cold regions. They live in waters with depths of 20 to 60 meters, and occasionally there are sightings along the coasts. After humans, killer whales are the most distributed mammals on the Earth.

The list of countries they inhabit is very long but includes:
Canada, France, Greenland, Portugal, Iceland, Ireland, Italy, Oman, Pakistan, India, Vietnam, Yemen, Bangladesh, Benin, Brunei, Cambodia, United Arab Emirates Uruguay, Venezuela, Mexico, Costa Rica, Dominican Republic, Singapore, Saint Vincent and the Grenadines, China, Japan, Philippines, Jamaica, Honduras, Ecuador, Colombia, Antigua and Barbuda, Russia, Papua New Guinea, Madagascar, Haiti and Brazil.

Orcas can inhabit deep or shallow waters as well as visit bays, estuaries, and even rivers. They dwell in all kind of marine aquatic habitats.

WHAT DO THEY EAT? DIET AND EATING HABITS.

It is the largest mammal predator and feeds on a wide variety of large or small species, warm-blooded or cold-blooded, whether dangerous or not. Orcas do not discriminate. A daily intake of 45 kilograms may include seals, sea lions, fishes, squids, turtles, birds (even penguins), sea otters and even animals considered as predators like sharks. Killer whales even prey on baleen whales or dolphins.

When orcas consume small prey, they swallow it completely, but they have to split the large ones into smaller pieces before ingesting them, which usually do it by shaking the victim violently. They have several hunting strategies depending on the type of prey and the region they inhabit. For example, in the North Pacific, they feed on some fish, seabirds, and sharks.

Cooperative hunting is a demonstration of their sociability and their intelligence. First, a group of orcas follow a prey and corner it. When the prey is exhausted, the orcas give the victims powerful blows with their tail before eating them.

Orcas in the wild.

HOW DO THEY REPRODUCE? MATING AND REPRODUCTION.

Killer whales have a polygamous reproduction system, and both genders mate with multiple individuals throughout their life. Females are sexually mature at an age ranging from 6 to ten years, and males between 10 and 13 years. Both can mate at any time of the year although in the northern hemisphere this occurs more frequently during October and March.

After a gestation period of 14-18 months, the mother gives birth to one calf; this happens one time every 3-8 years until the female turns 40 years old. A mother provides dedicated maternal care because the breeding depends entirely on her for feeding and protection. When the calf is 1 or 2 years old, it is weaned but continues in its native pod.

HOW DO THEY BEHAVE? BEHAVIOR.

It is a sociable species with a complex social structure. They live, reproduce and feed in pods of up to 40 or 50 members forming temporal superpods with more members sometimes. In general, these pods have 20 percent of mature males, 20 percent of offspring and 60 percent of females and young males. Orcas always stay in the mother’s group.

In some cases, an elementary unit may consist of a mature female, her adult offspring and the offspring of her daughters. Sometimes, some pods have a small number of members but with no close links.

On the other hand, killer whales can communicate through various sounds that other orcas in the pod recognize even though they are several kilometers away. Jaw claps, pulsed calls, pops, and whistles, are part of their communication sounds as well as echolocation clicks.

WHAT IS THEIR CONSERVATION STATUS? THREATS AND CONSERVATION.

State of conservation: Data deficient.
* But the population of some regions is in danger of extinction.

For centuries, orcas have frequently been hunted for oil and meat. Now, commercial fishing is not a significant hazard, but bycatch is. Also, they are very vulnerable to the contamination of their habitat as nocive chemicals can penetrate their skin and tissues; Consequently, this affects their reproductive and survival capabilities.

While there isn’t an assessment of the conservation status of the entire species, the population of some regions is in danger of extinction, such as that of British Columbia and Washington, in the United States. For this reason, CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora) has included the species in Appendix II of the species whose trade is controlled. The IUCN Red List does not have enough data to establish it in a category.

In 2008, NOAA (National Oceanic and Atmospheric Administration) through the National Marine Fisheries Service announced a Recovery Plan for Southern Resident Orcas to improve the living conditions of these cetaceans.

References

http://www.iucnredlist.org/details/15421/0

http://www.nmfs.noaa.gov/pr/species/mammals/whales/killer-whale.html

William F. Perrin, Bernd Würsig, J.G.M. ‘Hans’ Thewissen. Encyclopedia of Marine Mammals. Academic Press, 2009. Page 650.

Ford, Ellis, Balcomb. Killer Whales: The Natural History and Genealogy of Orcinus Orca in British Columbia and Washington. UBC Press, 2000.