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.

Irrawaddy Dolphin

Irrawaddy dolphin

The Irrawaddy dolphin is a euryhaline species of oceanic dolphin found in scattered subpopulations near sea coasts and in estuaries and rivers in parts of the Bay of Bengal and Southeast Asia. It closely resembles the Australian snubfin dolphin, which was not described as a separate species until 2005. It has a slate blue to a slate grey colour. Although found in much of the riverine and marine zones of South and Southeast Asia, the only concentrated lagoon populations are found in Chilika Lake in Odisha, India and Songkhla Lake in southern Thailand.

One of the earliest recorded descriptions of the Irrawaddy dolphin was by Sir Richard Owen. in 1866 based on a specimen found in 1852, in the harbour of Visakhapatnam on the east coast of India.

These dolphins are thought to reach sexual maturity at seven to nine years. In the Northern Hemisphere, mating is reported from December to June. Its gestation period is 14 months; cows give birth to a single calf every two to three years. Length is about 1 m (3.3 ft) at birth. Birth weight is about 10 kg (22 lb). Weaning is after two years. Lifespan is about 30 years.

There are plenty of food items that this dolphin feeds upon. They include fish, crustaceans, and cephalopods. During foraging periods, herds of about 7 dolphins will circle around prey and trap their victim. These prey entrapments occur slightly below the water surface level.

Although sometimes called the Irrawaddy river dolphin, it is not a true river dolphin, but an oceanic dolphin that lives in brackish water near coasts, river mouths, and estuaries. It has established subpopulations in freshwater rivers, including the Ganges and the Mekong, as well as the Irrawaddy River from which it takes its name. Its range extends from the Bay of Bengal to New Guinea and the Philippines, although it does not appear to venture off shore. It is often seen in estuaries and bays in Borneo Island, with sightings from Sandakan in Sabah, Malaysia, to most parts of Brunei and Sarawak, Malaysia. A specimen was collected at Mahakam River in East Kalimantan the local name comes from it.

Presence of the species in Chinese, Taiwanese, and Hong Kong’s waters has been questioned as the reported sightings have been considered unreliable, and the easternmost of ranges along Eurasian continent is in Vietnam.

No range-wide survey has been conducted for this vulnerable species; however, the worldwide population appears to be over 7,000. In India, Irawaddy dolphins are mostly found in Chilika Lake. Known subpopulations of Irrawaddy dolphins are found in eight places, listed here in order of population, including conservation status.
It is found in coastal waters of the Bay of Bengal, Sundarbans mangrove forest in the brackish-water Chilika Lake.

Conservation is hard, as this species is found in waters alongside developing nations. As such, they are working hard to food their population and give them a better life – which is generally a place where conservation is a low priority.

Of course, this can help – tourism is an increasingly large worldwide industry. As such a tourism industry, built around seeing this species could create a whole large number of extra jobs. Given the large ecotourism industry of India, it seems an easy extension to add this area.

Below this is a video of the species for your interest. Below that, is an amalgamation of any articles written on this species (we hope to add many in the future). Below that, I will add any links I make to help with you seeing the species in the wild. If you work in tourism and ever see this species, do get in touch, we would love to help people find you.

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.

Risso’s Dolphin

Risso's Dolphin by Citron

 Risso’s dolphin is the only species of the genus Grampus. Some of the closest related species to these dolphins include: pilot whales , pygmy killer whales, melon-headed whales, and false killer whales; looking at the pictures, it is perhaps clear that these are similar – they do have similar shapes. 

Risso’s dolphin is named after Antoine Risso, whose study of the animal formed the basis of the recognized description by Georges Cuvierin 1812.

As you can see from the map, their range is pretty large, emcompassing much of the worlds land that lies near land, though not all. Estimated numbers given add up to 300,000 though the number is probably higher, as many areas have not been calculated, and as such their is no global estimate.

The belong to Appendix ii, though they have an unfavourable status.

Below is a video of a risso dolphin, below that is a list of any places where it has been mentioned on this website (or will be in the future) and below that we will try to list places where you can see these animals.

One place to see Risso dolphin (not always, but from time to time) is Cardigan bay on the west side of Wales in the UK

Rough-toothed Dolphin

Rough toothed dolphin

The rough-toothed dolphin  is a species of dolphin that can be found in deep warm and tropical waters around the world. The only member of the genus Steno, but more recent evidence has found that, despite its prominent bill, it in fact belongs with the blunt-nosed dolphins in the subfamily Globicephalinae.

The are found in the Pacific, Atlantic, and Indian Oceans, and in the Mediterranean Sea, in warm temperate to tropical waters, with occasional reports from cooler environments. Rough-toothed dolphins can also bee seen regularly in locations stretching from the Windward Islands to Cape Verde, but only a small handful have been seen in Azores and Madeira. Live sightings are almost universally made far off-shore, beyond the continental shelf, in water at least 1 kilometre deep.

Most of the research activity concerning the dolphin has been directed in the eastern Pacific, where a population estimate of 150,000 was obtained by researchers in the 1980s.

In the Mediterranean Sea, the species was once considered to be visiting from North Atlantic, however, recently a small resident population was found in the eastern section of this ocean.

Rough-toothed dolphins are typically social animals, although solitary individuals are also sighted. An average group has between ten and twenty members, but they can vary from as few as two to as many as ninety. Such groups are thought to be temporary assemblages, composed of smaller, more permanent groups of two to eight closely related individuals that occasionally join with others. They have also been reported to join groups with other species of dolphin, and with pilot whales, false killer whales and humpback whales. 

Conservation status

The population is not believed to be threatened by human activities. A small number of individuals have been harpooned by Japanese whalers and pods are also slaughtered in the Taiji drive hunts. Others have been caught in seine nets by trawlers fishing for tuna. Less than a dozen rough-toothed dolphins live in dolphinarium around the world.

Below this, you will find a short video of these dolphins at sea. Below this, will be a list of any times it has been mentioned (being a specific type of dolphin it is not likely to be mentioned a great deal). Below this, we will add any links which will help you view it in the wild (do get in touch if you work in tourism around this species, we are keen to list your services, fill in the form at the top of the front page – list your wild place).

Melon-headed Dolphin

Melon-headed whale

The melon-headed whale (other names include electra dolphin, little killer whale, or many-toothed blackfish), is a toothed whale of the oceanic dolphin from the Delphinidae family. The common name came from the shape of the head. Melon-headed whales are widely distributed throughout deep tropical and subtropical waters worldwide, but they are rarely encountered at sea.

They are found near shore mostly around oceanic islands, such as Hawaii, French Polynesia, and the Philippines.

Melon-headed whales are a highly social species and usually travel in large groups of 100 – 500 individuals, with occasional sightings of herds as large as 1000–2000. Large herds appear to consist of smaller subgroups that aggregate into larger groups. Data from mass strandings in Japan suggest melon-headed whales may have a matrilineal social structure (i.e., related through female kin/groups organized around an older female and their relatives); the biased sex ratio (higher number of females) of the stranding groups suggesting mature males may move between groups. While melon-headed whales associate in large groups (a common trait amongst the oceanic dolphins, in contrast to the smaller group sizes of other blackfish species) their social structure may be more stable and intermediate between the larger blackfish (pilot whales, killer whales and false killer whales) and smaller oceanic dolphins. However, genetic studies of melon-headed whales across the Pacific, Indian and Atlantic Ocean basins suggest that there is relatively high level of connectivity (inter-breeding) between populations. This indicates that melon-headed whales may not show strong fidelity to their natal group (the group into which the individual was born) and that there are higher rates of movement of individuals between populations than in other blackfish species. Larger group sizes may increase competition for prey resources, requiring large home ranges and broad-scale foraging movements. Observations of daily activity patterns of melon-headed whales near oceanic islands suggest they spend the mornings resting or logging in near-surface waters after foraging at night. Surface activity (such as tail slapping and spy-hopping) and vocalizations associated with socializing (communication whistles, rather than echolocation, clicks used for foraging) increase during the afternoons. The daily pattern of behaviour observed in island-associated populations, combined with the larger group sizes of melon-headed whales (compared to that typically seen in other blackfish species) is more similar to the fission-fusion spinner dolphins. These behavioural traits may relate to predation avoidance (bigger groups offer some protection from large oceanic sharks) and foraging habits (both species are nocturnal predators that prey on predictable, relatively abundant mesopelagic squid and fish that make diel vertical migrations from the deep-sea to the surface). Melon-headed whales frequently associate with Fraser’s dolphins, and are also sighted, although less commonly, in mixed herds with other dolphin species such as spinner dolphins, common bottlenose dolphins, rough-toothed dolphins, short-finned pilot whales and pantropical spotted dolphins. A unique case of inter-species adoption between (presumably) an orphaned melon-headed whale calf and a common bottlenose dolphin mother was recorded in French Polynesia. The calf was first observed in 2014 at less than one month of age, swimming with the bottlenose dolphin female and her own biological offspring. The melon-headed whale calf was observed suckling from the bottlenose dolphin female, and was repeatedly sighted with its adoptive/foster mother until 2018.In August 2017 off the island of KauaÊ»i, HawaiÊ»i, a hybrid between a melon-headed whale and rough-toothed dolphin was observed travelling with a melon-headed whale amongst a group of rough-toothed dolphins. The hybrid superficially resembled a melon-headed whale, but closer observation revealed it had features of both species and some features intermediate between the two species, particularly in head shape. Genetic testing of a skin biopsy sample confirmed that the individual was a hybrid between a female melon-headed whale and a rough-toothed dolphin male.
Melon-headed whales may be predated upon by large sharks and killer whales.Scars and wounds from non-lethal bites of cookie cutter sharks have been observed on free-ranging and stranded animals.

Little is known about the reproductive behaviour of melon-headed whales. The most information comes from analyses of large stranding groups in Japanese waters, where sexual maturity for females is reached at 7 years of age. Females give birth to a single calf every 3–4 years after a gestation of approximately 12 months. Off Japan, the calving season appears to be long (from April to October) without an obvious peak. In Hawaiian waters newborn melon-headed whales have been observed in all months except December, suggesting births occur year-round, but sightings of newborns peak between March and June. Newborn melon-headed whales have been observed in April and June in the Philippines. In the Southern Hemisphere calving also appears to occur over an extended period, from August to December. Melon-headed whales are known to mass strand, often in groups numbering in the hundreds, indicative of the strong social bonds within herds of this species. Mass strandings of melon-headed whales have been reported in Hawaiʻi, eastern Japan, the Philippines, northern Australia, Madagascar, Brazil and the Cape Verde Islands. Two of these mass stranding events have been linked to anthropogenic sonar, associated with naval activities in Hawaiʻi and high frequency multi-beam sonar used for oil and gas exploration in Madagascar. The mass stranding at Hanalei Bay, Kauaʻi, Hawaiʻi is more precisely described as a ‘near’ mass stranding event, as the group of 150 melon-headed whales was prevented from stranding by human intervention. The animals occupied the shallow waters of a confined bay for over 28 hours before being herded back into deeper waters by stranding response staff and volunteers, community members, state and federal authorities. Only a single calf is known to have died on this occasion. The frequency of mass strandings of melon-headed whales appears to have increased over the past 30+ years. Melon-headed whales are fast swimmers; they travel in large, tightly packed groups and can create a lot of spray when surfacing, often porpoising (repeatedly leaping clear of the water surface at a shallow angle) when travelling at speed, and are known to spyhop and also may jump clear out of the water. Melon-headed whales can be wary of boats, but in some regions will approach boats and bow-ride. The world population is unknown, but abundance estimates for large regions are approximately 45,000 in the eastern tropical Pacific Ocean 2,235 in northern Gulf of Mexico  and in the Philippines 920 in the eastern Tañon Strait, Negros Island. There are two known populations in Hawaiʻi: a population of approximately 450 individuals resident to shallower waters of the northwest side of Hawaiʻi Island (the ‘Kohola resident population’) and a much larger population of approximately 8,000 individuals that moves among the main Hawaiian Islands in deeper waters. Hawaiʻi Island resident population has a restricted range (sightings have only been recorded off the northwest side of Hawaiʻi Island), and at times most of, or the entire resident population can be together in a single group, there is some concern that this population may be at risk from fisheries interactions, and exposure to anthropogenic noise, particularly in light of U.S. Navy activities in the region, given the potential link between sonar and mass stranding events.

Whale watching

Regions in which melon-headed whales can be reliably sighted are few, however Hawai’i, the Maldives, the Philippines, and in the eastern Caribbean, especially around Dominica, are the best places to see them. The International Whaling Commission (IWC) has guidelines for whale watching to ensure minimum disturbance to wildlife, but not every operator adheres to them.

Negative impacts from humans range through noise pollution hunting and by-catch among others.

Conservation status

The melon-headed whale is listed as Least Concern on the IUCN Red List. There is little information available on current levels of bycatch and commercial hunting, therefore the potential effects on melon-headed whale populations are undetermined. The current population trend is unknown.

The species is listed on Appendix II  of (CITES). The melon-headed whale is included in the Convention on the Conservation of Migratory Species of Wild Animals (CMS) Memorandum of Understanding Concerning the Conservation of the Manatee and Small Cetaceans of Western Africa and Macaronesia (Western African Aquatic Mammals MoU) and the Memorandum of Understanding for the Conservation of Cetaceans and Their Habitats in the Pacific Islands Region (Pacific Cetaceans MoU). As with all other marine mammal species, the melon-headed whale is protected in United States waters under the Marine Mammal Protection Act (MMPA).

Below lists any posts which mention this species (i hope they will increase over time). Below this is a video, and below this, I will list any places where you can attempt to see this species.

Pygmy Killer whale

Pygmy killer whale

The pygmy killer whale is a poorly known and rarely seen oceanic dolphin. It is the only member of the genus Feresa. It gets its name because of several similarities between it and the killer whale (or Orca). It is actually the smallest cetacean which includes the word whale in its name. While there have been occasions when it has been extremely aggressive in captivity, this has never been observed in the wild.

First described by John Gray in 1874, this was only on the basis of 2 skulls found in 1827 and 1874. The next recorded sighting was in 1952 which led to its formal naming by Japanese cetologist Munesato Yamada in 1954.

Pygmy killer whales are most often misidentified with melon-headed whales and false killer whales. For instance, a published paper describing an encounter with a school of pygmy killer whales was later determined to be either a mixture of pygmy and false killer whales or solely false killer whales.

The three species can be differentiated by physical differences between them. One defining difference is, although both species have white around the mouth, on pygmy killer whales the white extends back onto the face. Pygmy killer whales also have rounded-tipped dorsal fins, as opposed to pointed tips. When compared to false killer whales, pygmy killer whales have a larger dorsal fin. Finally, pygmy killer whales have a more clearly defined line where the dark dorsal colour changes to the lighter lateral colour than either of the other two species.

Behavioural differences can also be used to differentiate pygmy killer whales from false killer whales. Pygmy killer whales usually move slowly when at the surface whereas false killer whales are highly energetic. Pygmy killer whales rarely bow ride but it is common in false killer whales.

The small size of this species also causes confusion with other dolphins especially where the frontal head shape of the animals encountered remains unseen. Unlike the melon-headed whale, pygmy killer whales do not normally lift the full face above the water as they surface to breathe so it is not easy to confirm the lack of a bottle. Furthermore, in calmer waters the small bow wave pushed in front of the face looks like a bottle from a distance.

Found in all the world tropical and subtropical oceans, the only ocean with even a rough estimate is the eastern tropical pacific ocean, with an estimate of just short of 40,000 however, this is an estimate and therefore could be way out.

In terms of conservation status, they are least concern (according to the IUCN). Around Sri Lanka they make up around 4% of the by-catch in drift gill nets (one would think that these nets should be banned, or at least a change needs to be found). They can host a variety of parasites, and they are prone to mass strandings, though it is not yet clear why these occur.

Below is a video, below that is a list of anywhere they have (or perhaps will be mentioned in the future). Below that, we will list any contacts that will help you try to see this illusive animal.

Long-finned Pilot Whale

Long-finned pilot whale

The long-finned pilot whale is not actually a whale at all. Instead it is a large species of oceanic dolphin. It shares the genus Globicephala with the short-finned pilot whale (as you will see on the whale and dolphin page). Long-finned pilot whales are known as such because they have unusually long pectoral fins. Pilot whales get their name from the original belief that there was a “pilot” or lead individual in their groups. The name for the genus, Globicephala is derived from a combination of Latin (“globe”) and Greek kephale (“head”). The specific name is Greek for “black”. This species has also earned the nickname of “pothead whale” in some places because the shape of its head reminded early whalers of black cooking pots.

There is sexual dimorphism in the species. Females grow to a maximum length of up to 6m (20ft), and a maximum weight of up to 2,500kg (5,500lb). Males are significantly larger at up to 7.6 m (25ft) in length, and weigh up to 4,500kg (9,900lb). This makes the long-finned pilot whale the second largest member of the dolphin family, behind the Killer whale (Orcinus Orca).The long-finned pilot whale is top of the list of animals by number of neurons more neocortical neurons than any mammal studied to date, in fact having almost twice as many as humans.

While they can bee seen in groups of several thousand, they are generally an amalgamation of a number of smaller groups. Generally they belong to pods that lie in size from 20-150, with individual family groups of 8-10 adding together to make this group.

 They make a variety of noises, as well as using echolocation in water too murky to use their eyes. In deep dives, the females on either end appear to make the decisions.

They are Considered least concern, with a north atlantic population of around 780,000 though this includes short-finned pilots whales as it is hard to tell them apart.

Below, you will find a video of these animals. Below that, you will find any articles on this subject that have been written or will be. Below that, I will add any links that will allow you to see this species in the wild.

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