Category: mammal

Hectors Dolphin

Hectors Dolphin photo by Avenue

Hectors Dolphin

Hector’s dolphin  is one of four dolphin species belonging to the genus Cephalorhynchus. Hector’s dolphin is the only cetacean endemic to New Zealand, and comprises two subspecies: C. h. hectori, the more numerous subspecies, also referred to as South Island Hector’s dolphin; and the critically endangered Māui dolphin (C. h. maui), found off the West Coast of the North Island.

It is the smallest dolphin species with adults length between 1.2 and 1.6m. The species’ range includes murky coastal waters out to 100 m (330 ft) depth, though almost all sightings are in waters shallower than 50 m (160 ft). Hector’s dolphins display a seasonal inshore-offshore movement; favouring shallow coastal waters during spring and summer, and moving offshore into deeper waters during autumn and winter. They have also been shown to return to the same location during consecutive summers, displaying high foraging site fidelity. The inshore-offshore movement of Hector’s dolphins are thought to relate to seasonal patterns of turbidity and the inshore movements of prey species during spring and summer.

There are 2 subspecies,

  • South Island Hectors dolphin – Threatened, and with a decreasing population, currently thought to number around 10,000
  •  Maui dolphin – critically endangered, population under 50.
These diverged 50,000-60,000

Below, you will see a list of articles on this subject, and below that, you will see a video on this species

Below both of these, we will add links and information (as we get it) so that you can see these dolphins if you are in the area.

Haviside Dolphin

Haviside dolphin by Joachim Huber

Haviside Dolphin

Heaviside’s dolphin is one of four dolphins in the genus Cephalorhynchus. The small cetacean is endemic to the Benguela ecosystem along the southwest coast of Africa. Heaviside’s are small and stocky with adults reaching a maximum length of 1.7m and weight of75 kg. The dolphin has a distinct black, grey and white body pattern, making it hard for it to be confused with any other dolphin found in the same waters. The head is cone shaped with a blunt beak. The dorsal fin is triangular in shape and centred in the middle of the back. The head and thorax are coloured light grey with darker patches around the eye. The dorsal fin,& fluke and dorsal cape are a dark grey to almost black with a band that extends forward from the dorsal fin to the blowhole. The underbelly is white, with bands that extend onto the lower rear of the body. Small white patches are located just behind the pectoral fins and a single white patch extends between these fins on the chest. Sexual dimorphism is minimal, however variation in the shape of the white patch covering the genital slit is distinct between genders. In males, the patch ends in a point, but in females widens out to cover the mammary slits.

Information on reproduction is limited for Heaviside’s dolphins, however they are thought to be comparable to Hector’s and Commerson’s dolphins. Females and males reach sexual maturity approximately between 5–9 years. Mating is thought to occur year-round, however individual females may only produce calves every 2–4 years. Gestation time is unknown. Maximum known lifespan is based on the oldest recorded individual at 26 years old. Levels of predation are unknown, however killer whales(Orcinus orca) are known predators and there is evidence of shark attack from body scars.
Heaviside’s have small home ranges of 50–80km as measured using satellite telemetry over 2–3 months and photographic resighting over up to 3 years.

 Some individuals have been resighted at the same location for up to 10 years. Prior to 2018, the “International Union for Conservation of Nature” International Union for Conservation of Nature (IUCN) listed the Heaviside’s as ‘Data Deficient’ however, as of 2017 the status was changed to ‘Near Threatened’, owing to improved knowledge on the species from multiple studies. Despite this, the overall population trend remains unknown, and there are many aspects of the species biology that remain to be studied. Heaviside’s dolphin is listed on Appendix II of the “Convention on the Conservation of Migratory Species of Wild Animals” Convention on the Conservation of Migratory Species of Wild Animals Memorandum of Understanding Concerning the Conservation of the Manatee and Small Cetaceans of Western Africa and Macaronesia. Memorandum of Understanding Concerning the Conservation of the Manatee and Small Cetaceans of Western Africa and Macaronesia. The Memorandum of Understanding was established in 2008 and aims to protect these species at a national, regional and global level.

Below here is a video of some of these dolphins, and below that is our usual list of articles on this species (we hope this number will increase in the near future).

Below this, we will add links for you to go and see these dolphins for yourself

Commerson Dolphin

Commison Dolphin

Commerson’s dolphin  (also known as  jacobita, skunk dolphin, piebald dolphin, panda dolphin, or tonina overa (in South America), is a small oceanic dolphin of the genus Cephalorhynchus. The dolphin takes its name from the  French naturalist Dr Philibert Commerson, who first described them in 1767 after sighting them in the Strait of Magellan. To the right of this is a map of the Primary subspecies, the secondary subspecies lives a large distance out into the Indian ocean.

There are two geographically-isolated but locally-common subspecies. The principal subspecies, C.c.commersonii, has sharply-delineated black-and-white patterning and is found around the tip of South America. The secondary subspecies, C.c.kerguelenensis, is larger than C.c.commersonii, has a less-sharply delineated dark and light grey patterning with a white ventral band, and is found around the Kerguelen Islands in the Indian Ocean.

Commerson’s dolphin is very active. It is often seen swimming rapidly on the surface and leaping from the water. It also spins and twists as it swims and may surf on breaking waves when very close to the shore. It will bow-ride and swim behind fast-moving boats. It is also known to swim upside-down, which is thought to improve the visibility of its prey.

This dolphin feeds on a mix of coastal and pelagic fish and squid. Those in the South American subpopulation supplement their diets with crustaceans Individuals have been recorded as entering the Santa Cruz River to forage there during low tide. They can be found in estuaries, especially during the breeding season.
The IUCN lists Commerson’s dolphin as Least Concern in its Red List of Threatened Species. The proximity of the dolphin to the shore makes accidental killing in Gillnet a common occurrence. The dolphin was killed for use as crab Bait (luring substance) by some Argentinian and Chilean fishermen in the 1970s and 1980s, but this practice has since been curtailed. The Commerson’s dolphin population of South America is listed on Appendix II of the “Convention on the Conservation of Migratory Species of Wild Animals” Convention on the Conservation of Migratory Species of Wild Animals. It is listed on Appendix II as it has an unfavourable conservation status or would benefit significantly from international co-operation organised by tailored agreements.

There are a few of these dolphins in captivity.

Below is a video (there are clearer captive videos do have a look) below that will be a list of any stories on this species

Below that, I will add any links to people who can help you see these species in the wild.

Black Dolphin

Black Dolphin (Chilean)

The Chilean dolphin , also known as the black dolphin, is one of four dolphins in the genus Cephalorhynchus. The dolphin is found only off the coast of Chile; it is commonly referred to in the country as tonina. The Chilean dolphin is small at around 1.7 metres (5 ft 7 in) in length, with a blunt head., which means that it is regularly confused with a porpoise.

The population of the Chilean dolphin, perhaps one of the least studied of all cetaceans, is not known with certainty. There may be as many as a few thousand individuals, although at least one researcher, Steve Leatherwood, has suggested the population may be much lower.

The Chilean dolphin is listed on Appendix II Convention on the Conservation of Migratory Species of Wild Animals (CMS). It is listed on Appendix II as it has an unfavourable conservation status or would benefit significantly from international co-operation organised by tailored agreements. The total population is thought to be under 5000.

Below, you will first find a video on this species. Under this, you will find a list of any articles that have been written on this species (or any that will be written by the time you look). Below that, I will add any links that will help you see these animals in the wild.

White-beaked dolphin

White beaked dolphin

The white-beaked dolphin  is a marine mammal belonging 

to the family Delphinidae (oceanic dolphins) in the sub order Odontoceti (toothed whales). Their distribution is shown in the map.

The white-beaked dolphin is endemic to the cold temperate and subarctic waters of the North Atlantic Ocean, most commonly in seas less than 1,000 m (3,300 ft) deep. Due to the fact they are not fully adapted to Arctic conditions, they are more vulnerable to predators, most notably polar bears. Within this wider region, white-beaked dolphins are most commonly found in four locales: on the Labrador Shelf close to southwestern Greenland, around Iceland, off the northern and eastern coasts of Britain, and off the coast of Norway. In the Faroe Islands between Iceland and the United Kingdom the White-beaked dolphin is at risk of being hunted during drive catches of the long-finned pilot whales. They may also be incidentally trapped in the purse-sein and trawl nets of the area. There are no recognised subspecies.

The dolphin may easily be misidentified as the Atlantic white-sided dolphin, although the white-beaked is commonly found further north. The white-beaked dolphin is also typically larger, and does not have yellow streaks on its side.

Below is a video (no sound) of them filmed under water off the coast of the UK. Northern parts of the UK have populations, including Lyme bay and areas around the hebrides.

They are thought to number 100,000, so are listed as least concern.

Pacific white-sided dolphin

Pacific white-sided dolphin

The Pacific white-sided dolphin, also called the hookfin porpoise, is an active dolphin found in the cool or temperate waters of the North Pacific Ocean.

The Pacific white-sided dolphin was named by Smithsonian mammalogist Theodore Nicholas Gill in 1865. It is morphologically similar to the dusky dolphin, which is found in the South Pacific.[6] Genetic analysis by Frank Cipriano suggests the two species diverged around two million years ago.

Though traditionally placed in the genus Lagenorhynchus. Molecular analyses indicate they are closer to dolphins of the genus Cephalorhynchus, in the Lissodelphininae subfamily, than to both the Atlantic white-sided dolphin and the White-beaked dolphin. It has therefore been proposed to move the Pacific white-sided dolphin to the resurrected genus Sagmatias together with other southern hemisphere species (hourglass dolphin, Dusky dolphin and Peale’s dolphin).  However, there is still some analysis to do, before this move can take place.  White-sided dolphins swim in groups of 10 to 100, and can often be seen bow-riding and doing somersaults. Members form a close-knit group and will often care for a sick or injured dolphin. Animals that live in such large social groups develop ways to keep in touch, with each dolphin identifying itself by a unique name-whistle. Young dolphins communicate with a touch of a flipper as they swim beside adults.

United Nations banned certain types of large fishing nets in 1933, many Pacific white-sided dolphins were killed in drift nets. Some animals are still killed each year by Japanese hunting drives

There are around 100 in dolphinarias in the USA and Japan. They are currently listed as least concern

Below is a list of any articles on the species, and below that a video of it. Under this, I will add any links that might help you see this species in the wild.

Hourglass dolphin

Hourglass dolphin

The hourglass dolphin  is a small dolphin in the family Delphinidae that inhabits offshore Antarctic and sub-Antarctic waters. It is commonly seen from ships crossing the Drake Passage, but has a circumpolar distribution.

The species was identified as a new species by Jean René Constant Quoy and Joseph Paul Gaimard in 1824 from a drawing made in the South Pacific in 1820. It is the only to have been widely accepted as a species solely on witness accounts.

Sighting surveys were conducted in 1976–77 and 1987–88. Abundance was estimated to be 144,300 individuals, based on line transect sightings in January 1977 and January 1988 in northern Antarctic waters. This is the only abundance estimate of hourglass dolphins to date.

It is currently listed as least concern on the IUCN red list.

Below you will find a video of the species, and below this a list of any articles that have (or will be) written on this species. Under this, we will over time, hope to add links which will help you see this animal in the wild.

Atlantic white-sided dolphin

Atlantic white sided dolphin (by Anna)

Atlantic white-sided dolphin

The dolphin is slightly larger than most other oceanic dolphins. It is just over a meter in length at birth, growing to about 2.8 m (9.2 ft) (males) and 2.5 m (8.2 ft) (females) at maturity. Females reach sexual maturity at between 6 and 12 years, and males between 7 and 11 years. The gestation period is 11 months and lactation lasts for about 18 months — both typical figures for dolphins. Individuals are known to live for at least 17 years.

The key distinguishing feature is the white to pale yellow patch found behind the dorsal fin of the dolphin on each side.

Groups found off Newfoundland generally number around 60 while those found near Iceland much smaller. The diet of Atlantic white-sided dolphins includes mainly herring, hake and squid. However, they consume a large variety of prey including small mackerel and various bottom fish. They have been observed to cooperatively hunt on the surface. It has been suggested that larger groups split while feeding.

The estimations for the U.S. shelf and shelf-edge water suggest that the population size is about 300,000. Additional 120,000 individuals have been estimated to spend summer in the Gulf of St.Lawrence. In the eastern North America waters the numbers increase southwards in winter and spring in association with cold waters from the Gulf of Maine. The International Union of the Conservation of Nature (IUCN) currently classifies Atlantic white-sided dolphins as Least Concern. The North and Baltic Sea populations of the Atlantic white-sided dolphin are listed on Appendix II  of the Convention on the Conservation of Migratory Species of Wild Animals. They are listed on Appendix II as they have an unfavourable conservation status or would benefit significantly from international co-operation organised by tailored agreements. These species of dolphin are known to fall victims to in a polluted environment, a study from 1997 confirmed that the British and Irish populations of Atlantic white-sided dolphins to succumb to these effects.

Below is a list of any articles we might have written on the species, and below that is a video. Below this, we are hoping to add many links that will help you see these in the wild. If you work in tourism of this species or hospitality where they live, we would be interested in listing your services on here, to help people come and visit.

Dusky Dolphin

Dusky dolphin by AllenMoC

Dusky Dolphin

 

The dusky dolphin is a dolphin found in coastal waters in the Southern Hemisphere. Its specific epithet is Latin for “dark” or “dim”. It is a close relation of the Pacific white-sided dolphin, but current scientific consensus holds they are distinct species. The dolphin’s range is patchy, with major populations around South America, southwestern Africa, New Zealand, and various oceanic islands, with some sightings around southern Australia and Tasmania. The dusky dolphin prefers cool currents and inshore waters, but can also be found offshore. It feeds on a variety of fish and squid species and has flexible hunting tactics. The dusky dolphin is known for its remarkable acrobatics, having a number of aerial behaviours. The status of the dolphin is unknown, but it has been commonly caught in gill nets.

There is a sizable tourism industry around this species and others found in the same area.

Below is a list of any times this species is mentioned in the website, and below that is a video of this speices. Under both of these, I will list any links which will give you the chance to see this species yourself, and to help support its continual exinstance.

Short-finned pilot whale

Short-finned pilot whale

The short-finned pilot whale) is one of the two species of cetaceans in the genus Globicephala, which it shares with the long-finned pilot whale It is part of the oceanic dolphin family (Delphinidae).

It is found all around the world (avoiding the polar regions) with a global population of about 700,000, though watching them, there appear to be 3-4 distinct populations—two in the Pacific and one in the Atlantic and Indian Oceans. Its range is moving northward due to global warming. In the Pacific, males average 4–6 m  and females 3–5 m. generally stocky with black to dark gray or brown skin. It can be distinguished from the long-finned pilot whale by its  shorter flippers, fewer teeth, and a shorter beak. It is thought to pursue fast-moving squid typically at a depth of 700 m, but the maximum recorded depth is 1,018 m.

The short-finned pilot whale has been reported as being highly playful and social. It typically travels in pods of 10–30 members, usually family, but has been observed moving in groups of several hundred. Like killer whales, it has a matrilineal social hierarchy with an elder female at the head and a sizable post-reproductive lifespan. It is polygynous; females often outnumber males 8:1 in a pod.

Pods are known to mass strand, possibly due to sheer accident, biosonars confused by geomagnetic anomalies, injury from loud military sonar, or disease. It was historically whaled, and is still whaled today by Japan and the Lesser Antilles, but it is protected by several international treaties.

The total of all available abundance estimates for short-finned pilot whales is approximately 700,000 individuals, but populations vary worldwide, and large parts of the species’ range have not been surveyed, therefore actual abundance could be considerably greater than this.

In the western Pacific, population estimates range from 5,300 individuals in Northern Japan to 53,608 in Southern Japan. 7,700 individuals are reported in the eastern Sulu Sea (Philippines), and in the Eastern tropical Pacific the most recent estimate from 2000 gives 589,000 individuals. The resident population in Tenerife, Spain, is estimated at only 350 individuals.

The short-finned pilot whale was listed on the IUCN Red List as Data Deficient in 2008, and remains data-poor in much of its range, especially in the Southern Hemisphere and in large parts of the tropical and warm temperate North Atlantic Ocean.

You will find a video of the species below, and below that a list of any times it has been mentioned on this site (or is in the future). Below that, we will add any links for seeing this animal – as or when we get them.

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