This species was already only thought to have a wild population of 120, however the population has been found to have fallen to just 74 (a 38% reduction).
Just found in a fragment of rainforest on the Vietnam – China border, the remaining population is estimated to live in 11 family groups.
Surveys are capable of being done remotely, as the gibbons call loudly at certain times of the day (dawn) allowing them to be counted. Importantly, they have been able to “fingerprint” each of the gibbons by their unique calls. This means that a few handfuls of directional speakers should allow the ability to keep track of individuals across the whole forest (without having to put large numbers of researchers in the field each day.
To hear these creatures yourself, play the video above.
Once thought to be the same species as the Hainan black crested gibbon. It seems that this was an early false belief. This species will be added in the year future (indeed, if I succeed, its page will exist before this article goes live)
Thought to have gone extinct 295,000 and 215,000 years ago, having first appeared around 2 million years ago. Rather than being caused by our ancestors, it unfortunately became extinct as a result of the climate became more seasonal and the plant-eating primate struggled to adapt to changing vegetation.
Might this be a for-shadow for the extinction of the rest of the great apes?
The largest ever primate Gigantopithecus blacki went extinct at a time when Asian great apes were thriving, and its demise has long been a considered a mystery. A massive regional study of 22 caves in southern China explores a species on the brink of extinction between 295,000 and 215,000 years ago. As the environment became more seasonal, forest plant communities changed Primates such as orangutans adapted their eating habits and behaviors in response but G. blacki showed signs of stress, struggled to adapt and their numbers dwindled.
This species was 3m (10 feet) tall, it was around twice the weight of the the largest gorillas. It was first identified around 100 years ago, from fossilized teeth (around 2000 have been found) sold as dragon bones. Around(700,000 or) 600,000 years ago we start to see large environmental changes and during that period we see a decline in the availability of fruit.
As a result Giganto (ate) less nutritious fall-back foods. We’ve got evidence from looking at the teeth structure, Westaway added. Pits and scratches on the teeth suggest it was eating really fibrous food such as bark and twigs from the forest floor.
Funnily enough, they are not thought to have ever lived in caves, but instead had their remains carried there.
As there are no, non-cranial fossils (i.e. any fossils of any part of this species below the neck) , it’s hard to know exactly what Gigantopithecus would have looked like. Its upper molars are 57.8% larger than a gorilla’s and the lower molars are 33% larger, suggesting its body weight would have been 200 to 300 kilograms.
Given its size, it is thought to have long abandoned the tree-tops, though given its closest living relative is the Bornean Orangutan, of which, older males are often spending more time on the ground given their large weight as well.
There are fossils of homo erectus from nearby, from around 800,000 years ago, suggesting that we might well have lived alongside them. How happy or harmonious this relationship is, we cannot know. Unfortunately, given recent history, it is quite likely that directly or indirectly we had a hand in this species extinction, given our impact on almost all other species that we know.
There are perhaps only 10,000 of this species in China, though there are around 700,000 living across the border in South Korea (slightly different subspecies).
They are also doing well in the UK with around 2000 living in the country, having been introduced by the Duke of Bedford into his animal collection, and then quickly escaped (around 100 years ago)
This makes the UK an important part of this species survival. It is particularly easy to see in the Norfolk broads, but is also found in other counties in this area.
If anyone has been reading this blog for some time, you may remember me writing about an albino panda that was photographed in wulong nature reserve in China (click here to read it)
This bear has been caught on camera (see above) and appears to be doing well. It has started to display mating behaviour and appears to be extremely healthy. It has all the features generally associated with albinism, with white fur and red eyes.. It is now around 5-6 years old, and has been seen playing with other pandas, suggesting that its unusual colouring is not leading to it being shunned from other pandas.
It was filmed approaching a mother with a 2 year-old cub. As the mother was ready to mate again, and yet did not show aggression to this male bear getting close, it is likely that this female is the mother of the white cub.
Currently thought to be numbered 1800 in the wild, the panda is currently listed as threatened – having been delisted from being endangered in 2016. It is also an integral part of the Giant panda national park which is being created, and links 67 panda reserves, allowing the bears to travel between the former islands of habitat, giving them the ability to breed in a more natural way. This is important, as inbreeding would make panda conservation even harder.
Recent genetic analysis has shown that the red panda is not in fact a small bear, but instead has a closer relationship to raccoons, mustelids (badgers otters and the like) and skunks. However, what is even more fascinating, is that the next closest related family is in fact the pinipeds (seals sealions and similar) and only after this, do we find the giant panda amongst the other bears.
What is fascinating, though, is that this is the original panda. The red panda was discovered and named in 1825, while the giant panda was only discovered in 1869. I cannot find any articles on it, but I suspect that the red panda was also long-known about in China before its discovery as well.
It is not closely related to the giant panda, which is a bear, though they do share a number of features such as elongated wrist bones or “false thumbs” used for grasping bamboo (so-called convergent evolution; where distantly related species evolve the same features, because it allows each to survive well in the wild – eating what they eat (or similar). The evolutionary lineage of the red panda (Ailuridae) goes back as far as 18-25 million years ago, and there are a variety of fossils in this lineage, found in Europe and North America.
So what has happened in recent times? They were known to be found in two different places, one of them lives in the Himalayas and the other in China. What has been discovered in recent times, is that these are not only subspecies, but separate species – and are thought to have split 250,000 years ago. However, while this is clearly true, it may well need to be forgotten – there are only 10,000 red pandas left in the wild as the top possible estimate, some suggest that there are actually only 2500 – we may have no choice in conserving both species, but have to interbreed them to help just one mixed group of red pandas, rather than loosing all red pandas from the wild. They live in coniferous forests as well as temperate broadleaf and mixed forests, favouring steep slopes with dense bamboo cover close to water sources. Most of its nutrients come from bamboo stems and leaves,
Support for these wild populations is essential. The best way to help justify their long term survival, is for local people to see them as a financial gift. This can happen quickly, with not that many people going there.
Below is a video for each, below that is a list of any articles which mention this fascinating creature, and below that, we will add any links that will help you see these animals in the wild.
Today is red panda awareness day. Many people are not particularly sure what a red panda is. Indeed, when I volunteered in a local zoo, I often found myself standing...
Over the last couple of years, snow leopards have been sighted in Pingwu county - Sichuan province. This confirms that the range of the snow leopard has expanded eastward as...
Pandas, like many other mountain species, are liable to get marooned on islands in the sky, and recent genetic analysis has shown that there are really two species of giant...
China is in the process of creating a huge panda reserve covering 10,476 square miles. This reserve is three times the size of Yellowstone National Park in the USA. With...
We have watched with horror, the problems that Myanmar has suffered over the last few decades. Perhaps one of the positives though is the fact that often when this sort...
On this post, I will list a group of articles on North American politics and stories. It is unfortunately a fact, that, no matter what your position is on American...
I am intending to make this into a new set of articles that will appear on this website. Obviously, these species will not be the only ones that are covered...
The family Sirenia consists of 2 genus, the Dugongidae (only extant species is the Dugong) and Trichechidae which contains the 3 Manatee species.
The Dugong is the species in the top left (if you cannot pick it out). The Steller sea cow was a close relation of the Dugong
The big difference, is that unlike Manatees with a paddle shaped tail, where as Dugongs have fluked tails.
As always, as links are made to help with tourism, these will either appear below, or each species will be spun off to have its own page. Ecotourism need not have a big impact on the species and its natural behaviour, however, by giving them financial value to the local population you greatly increase the liklihood of survival as well as increasing the standard of living for local people.
Should you work in tourism dealing with these species, do get in touch, there is a link at the top of the home page, with a simple form.
Dugong– The only surviving Dugongidae after the stellers sea cow (described in 1741 and hunted to extinction by 1768 for hide meat and fat) was lost.
It is found in the waters of around 37 countries in the Indo-west Pacific. It has recently become functionally extinct in Chinese waters, and may well be lost entirely in the near future. Its thought that while their current range is highly fractured, it is probably still a similar limit to before. These countries between them, give around 140,000km of coastline, and this area maps with where the correct species of sea grasses grow. The worldwide population is thought to have declined 20% in the last 90 years, though this is pretty good compared to many other species.
There are currently thought to be 100,000, with its conservation status being Vulnerable
Amazonian Manatee-Found in parts of the Amazon basin, throughout parts of Brazil, ColombiaPeru and Ecuador.
It is the smallest of the surviving Manatees. Weights fall between 7,5kg and 350kg, with a 75cm-225cm length. Given that it is likely decreasing, it is going to be below this now.
They are exclusively herbivorous, feeding on water lettuce and hyacinth. During a day, they can consume around 8% of their bodyweight. This mostly occurs during the wet season, during the dry season they return to the main river and survive on their fat reserves. They have a prehensile snout (like a less developed trunk) for feeding
They are considered Vulnerable, with the last count giving an upper limit of 10,000, however, this was in 1997.
West-Indian manatee- So named, because they were first sighted amongst a group of Islands called the West-Indies in the Caribbean – it is no-where near India (as you can see). They live in shallow coastal areas. They have a prehensile snout (like a less developed trunk) for feeding. Unlike elephants, they are not limited to 6 sets of teeth, but only having molars (24-36) it is a simpler layout. As their range includes Florida (well known from the Everglades) this species is well known in places. They are hard to count, living in murky water,
Listed as vulnerable, the whole population is not thought to be greater than 10,000. The 2 subspecies are the Florida manatee (around 2500) and the Antillean Manatee which is found off the Atlantic coast of Mexico and central south America (particularly in the waters of greater Antilles) potentially, historically found along the coast of Texas (and as far north as Dennis, Tennessee).
African Manatee- (or West African Manatee) Although found both on the coast and inland, there is no significant genetic difference between these populations. African Manatees can be found in West African regions which include a wide range of countries – requiring cross nation action to save them. Manatees are found in brackish waters to freshwater: in oceans, rivers, lakes, coastal estuaries, reservoirs, lagoons, and bays on the coast.
The areas with the highest manatee populations are Guinea-Bissau, the lagoons of Côte d’Ivoire, the southern portions of the Niger River in Nigeria, the Sanaga River in Cameroon, the coastal lagoons in Gabon, and the lower parts of the Congo River. Alone amongst manatee species, the African manatee is Omnivorous, eating clams and molluscs as well as fish found in nets (can make up 50% of diet). They are more adaptable than other manatees, being able to survive in salt water (though they need access to fresh water to drink).
They are nocturnal, but many countries, a dead manatee is worth a lot to hunters. They are listed on CITES Appendix 1 with a population under 10,000. Cote d’Ivoire has a population of 750-800. Some of the biggest populations still live in Gabon, status is unknown in many areas. There is much tourism potential – worth a lot in Florida.
Dugongs, a close relation of the sea cow, have not done well over the last few centuries. In places like Australia they still live in large numbers. In places like...
On this post, I will list a group of articles on North American politics and stories. It is unfortunately a fact, that, no matter what your position is on American...
On this post, I will list a group of articles on North American politics and stories. It is unfortunately a fact, that, no matter what your position is on American...
The money will be used to expand wildlife corridors, which will allow easier gene flow, as well as benefitting all wildlife in the area - including prey which in places...
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.
The most abundant cetacean in the world, with around 6 million (it should be noted that there are 1350 humans in the world, for every individual common dolphin).
Despite this fact and its name, the common dolphin is not thought of as the model dolphin (that honour goes to the bottlenose dolphin due to its popular appearances in aquaria and the media). It did, however, feature heavily in Ancient Greek and Roman art and culture, most notably in a mural painted by the Greek Minoan civilization.
It is currently the only member of the genus Delphinus. The common dolphin belongs to the subfamily Delphininae, making this dolphin closely related to the three different species of bottlenose dolphins, humpback dolphins, striped dolphins, spinner dolphins, clymene dolphin, spotted dolphins, fraser’s dolphin and the tucuxi and guiana dolphin.[5] The common dolphin was originally categorized into two different species (now thought to be ecotypes), the short-beaked common dolphin and the long-beaked common dolphin. However, recent evidence has shown that generally long-beaked dolphins of this species have originated from the short-beaked population, and therefore there is no close links between different long-beaked dolphins in any part of the world.
Currently, the common dolphin is divided into four subspecies:
D. d. delphis, the nominate subspecies
D. d. bairdii, the Eastern North Pacific long-beaked common dolphin
D. d. ponticus, the Black Sea common dolphin
D. d. tropicalis, the Indo-Pacific common dolphin
A number of fossils were erroneously placed in the same genus, but this has since been corrected.
Common dolphins can live in aggregations of hundreds or even thousands of dolphins,though are often seen in groups numbering several hundred individuals (with subgroups consisting of 20-30 individuals). Occasionally, different groups will come together to form mega-pods which can consist of over 10,000 dolphins – quite a site to witness. Genetic studies in the Northeast Atlantic suggest that common dolphin pods generally do not consist of close kin, but rather of members that are not closely related. Unlike many delphinids, common dolphins do not live in a matriarchal society. That being said, closely related individuals are usually found in similar geographical locations fairly consistently, providing evidence that this species displays site fidelity (at least in the North-eastern Atlantic). Male common dolphins display greater site fidelity in relation to their kin than females.
Common dolphin pod structure often consists of nursery pods (which includes females and calves), bachelor pods (consisting of all males) and mixed groups of males and females, including sub-adults and calves. Genetic evidence seems to indicate that common dolphins live in fission-fusion societies, where dolphins form pods that are not necessarily stable and do not necessarily consist of related individuals. It is not known if common dolphins form lifelong bonds with other individuals like the long-term male alliances seen in bottlenose dolphins.
There is some evidence that common dolphins use signature whistles, similar to that of the bottlenose dolphin. These whistles are believed to serve as an acoustic label the dolphin equivalent of a name. It takes approximately 1 year for a calf to learn its signature whistle after which it remains stable for the rest of a dolphin’s life.
In South Africa, as many as 29 common dolphin signature whistle types were detected. However, it was difficult to determine if each dolphin had its own signature whistle due to the vast number of dolphins present (over 1,000) and anthropogenic background noise. Additionally, considering the vast number of dolphins present and taking into account their feeding and diving behaviour, it appears that common dolphin signature whistles are also used for group cohesion. Another hypothesis for the function of signature whistles, is that they serve as a beacon for lost individuals.
Common dolphins sometimes associate with other dolphin species, such as pilot whales (note, not actually whales). In the Gulf of Corinth, common dolphins frequently display mixed species association, especially with striped and Rissos’ dolphins. Over one third of all dolphin sightings in the gulf consisted of mixed species associations that partially consisted of common dolphins. In mixed species associations, the ratio of striped to common dolphins ranged from 6-11:1. When Rissos’ dolphins were present (there would usually be only one or two individuals), it appeared that much of their scars were the result of interactions between striped and spinner dolphins. In much of the interactions, the Rissos’ dolphins would chase and herd the common dolphins toward the boat, while the common dolphins would try and swim under the Rissos’ dolphin. When groups of common and striped dolphins would charge at each other, the Rissos’ dolphin would chase the striped dolphins. Sometimes these interactions appeared to be playful, and at other times aggressive. Synchronized swimming and surfacing was commonly observed. These interactions take place in the deepest part of the Gulf, furthest from shore and usually consist of a total of 60 dolphins from all three species.
There have been 15 cases of common dolphin and striped dolphin hybrids being recorded. Genetic and observational evidence has demonstrated that the hybrids are fertile and are capable of not only reproducing with other hybrids, but are capable of reproducing with each of the parent species. Striped dolphins have been known to mate with other dolphins, as the Clymene dolphin is the result of hybrid speciation between striped and spinner dolphins. However, this is unlikely to happen with common dolphins, as their population in the Gulf of Corinth is too low. Common dolphins and bottlenose dolphins have been known to interbreed in captivity. There is one confirmed case of a hybrid between a bottlenose and common dolphin in Southern Spain, an important feeding ground for both species. The mother was a female bottlenose dolphin (dubbed as Billie) who has spent 10 years within a common dolphin pod. Billie was observed assisting common calves reach the surface at three different intervals and would babysit the calves after the mother went through labour. They have also been observed bow riding on baleen whales, and they also bow ride on boats. They are fast swimmers and breaching behaviour and aerial acrobatics are common with this species. They are also known to display altruistic behaviours to support injured members.
The short-beaked common dolphin is pregnant for 10 to 11 months. The new-born calf has a length of 70 to 100 centimetres (2.3 to 3.3 ft) and weighs about 10 kilograms. For the Black Sea population, weaning occurs at between five and six months, but occurs later (up to about 19 months) in other areas. Typical interbirth interval ranges from one year for the Black Sea population to three years for eastern Pacific Ocean populations. Age of sexual maturity also varies by location, but can range between two and seven years for females and three and 12 years for males. No evidence exists of any major reproductive differences between the two species. In captivity, the long-beaked common dolphin has hybridized with the common bottlenose dolphin . One of the hybrids has been bred back to a bottlenose dolphin, demonstrating such hybrids are fertile.
Find our news section below this video of a megapod of common dolphins
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The striped dolphin (sometimes called the Euphrosyne dolphin) has been heavily researched and is found in temperate and tropical waters around the world. It has (until recently been included in the genus Stenella, but it has been shown to actually be an oceanic dolphin. According to a recent study, the closest relatives of the striped dolphin are the Clymene dolphin, the common dolphins, the Atlantic spotted dolphin, and “Tursiops” aduncus, which was formerly considered a subspecies of the common bottlenose dolphin. The striped dolphin was described by Franz Meyen in 1833.
The striped dolphin has a similar size and shape to several other dolphins that inhabit the waters it does (see pantropical spotted dolphin, Atlantic spotted dolphin, Clymene dolphin). However, its colouring is very different and makes it relatively easy to notice at sea. The underside is blue, white, or pink. One or two black bands circle the eyes, and then run across the back, to the flipper. These bands widen to the width of the flipper which are the same size. Two further black stripes run from behind the ear — one is short and ends just above the flipper. The other is longer and thickens along the flanks until it curves down under the belly just prior to the tail stock. Above these stripes, the dolphin’s flanks are coloured light blue or grey. All appendages are black, as well. At birth, individuals weigh about 10 kg (22 lb) and are up to a meter (3 feet) long. By adulthood, they have grown to 2.4 m (8 ft) (females) or 2.6 m (8.5 ft) (males) and weigh 150 kg (330 lb) (female) or 160 kg (352 lb) (male). Research suggested sexual maturity was reached at 12 years in Mediterranean females and in the Pacific at between seven and 9 years. Longevity is about 55–60 years. Gestation lasts about 12 months, with a three- or four-year gap between calving.
In common with other dolphins in its genus, the striped dolphin moves in large groups — usually up to thousands of individuals in number. Groups may be smaller in the Mediterranean and Atlantic. They may also mix with common dolphins. The striped dolphin is as capable as any dolphin at performing acrobatics — frequently breaching and jumping far above the surface of the water. Sometimes, it approaches boats in the Atlantic and Mediterranean, but this is dramatically less common in other areas, particularly in the Pacific, where it has been heavily exploited in the past. Striped dolphins are known as “streakers” throughout the eastern tropical Pacific due to their behavior of rapidly swimming away from vessels to avoid collisions.
The striped dolphin inhabits temperate or tropical, off-shore waters. It is found in abundance in the North and South Atlantic Oceans, including the Mediterranean (sightings and strandings have been reported rather recently in Sea of Marmara[6]) and Gulf of Mexico, the Indian Ocean, and the Pacific Ocean. Roughly speaking, it occupies a range running from 40°N to 30°S. It has been found in water temperatures ranging from 10 to 26 °C, though the standard range is 18-22 °C. In the western Pacific, where the species has been extensively studied, a distinctive migration pattern has been identified. This has not been the case in other areas. The dolphin appears to be common in all areas of its range, though that may not be continuous; areas of low population density do exist. The total population is in excess of two million. The southernmost record is of a stranded individual nearby Dunedin, southern New Zealand in 2017.[7]
Japanese whalers have hunted striped dolphins in the western Pacific since at least the 1940s. In the heyday of “striped dolphin drives”, at least 8,000 to 9,000 individuals were killed each year, and in one exceptional year, 21,000 individuals were killed, though since the 1980s, following the introduction of quotas, this number has fallen to around 1,000 kills per year. Conservationists are concerned about the Mediterranean population which is threatened by pollution, disease, busy shipping lanes, and heavy incidental catches in fishing nets such as long-liners, trawlers, gill nets, trammel and purse seine nets. . Recent threats include military sonar, and chemical pollution from near by harbours. Hydrocarbons are also a major concern such has PCBs (polychlorinated biphenyls) and HCB (hexachlorobenzene). These are said to give problems to additional food chains as well as doing a full body test to see what hydrocarbons may be passed down through parturition and lactation. Attempts have been made to keep the striped dolphin in captivity, but most have failed, with the exception of a few captured in Japan for the Taiji Whale Museum.
Striped dolphins are one of the targeted species in the Taiji dolphin drive hunt.
The adult striped dolphin eats fish, squid, octopus, krill, and other crustaceans. Mediterranean striped dolphins seem to prey primarily on cephalopods (50-100% of stomach contents), while north-eastern Atlantic striped dolphins most often prey on fish, frequently cod. They mainly feed on cephalopods, crustaceans, and bony fishes. They feed anywhere within the water column where prey is concentrated, and they can dive to depths of 700 m to hunt deeper-dwelling species.
The eastern tropical Pacific and Mediterranean populations of the striped dolphin are listed on Appendix II of the Convention on the Conservation of Migratory Species of Wild Animals (CMS), since they have an unfavourable conservation status or would benefit significantly from international co-operation organized by tailored agreements.[9]
On the IUCN Red List the striped dolphin classifies as vulnerable due to a 30% reduction in its subpopulation over the last three generations. These dolphins may also be an indicator species for long term monitoring of heavy metal accumulation in the marine environment because of its importance in the Japan pelagic food web as well as its ability to live for many years. Various other groups have signed memorandum, agreeing not to hunt them.
Conservation efforts have included having ship lines take a new path to their destination such as cruise lines as well as reduced human interaction close up. Feeding the dolphins has also become a problem, and has led to behavioural changes. This has also been suggested as another reason for mortality events.
The striped dolphin once thrived, numbering 127,880 before 1990. Since then, the population has suffered from incidental catches in fisheries. Mortality has been considered unsustainable, but there is a lack of data which hampers conservation efforts.
Various cases of stranding over the years have been a cause for alarm. With an unfavourable conservation status and the increasing amount of debris piling in the ocean every year, striped dolphin’s population is decreasing. 37 dolphins stranded off the Spanish Mediterranean coast were suffering from dolphin morbillivirus (DMV). The causes of these stranding have been changing from epizootic to enzootic.
There is a suggestion that theses strandings are caused by a virus, and that the virus is becoming more common.
The spinner dolphin (also known as the long-snouted dolphin (distinguishing it from the Clymene dolphin – which is often called the short snouthed spinner dolphin) is a small dolphin found in off-shore tropical waters around the world. It is famous for its spinning along its length, as it leaps from the water. It is a member of the familyDelphinidae of toothed whales.
The four named subspecies are:
Eastern spinner dolphin, found from the tropical eastern Pacific.
Central American or Costa Rican spinner dolphin, also found in the tropical eastern Pacific.
Gray’s or Hawaiian spinner dolphin, from the central Pacific Ocean around Hawaii but represents a mixture of broadly similar subtypes found worldwide.
Dwarf spinner dolphin, first found in the Gulf of Thailand.
The species, though, displays greater variety than these subspecies might indicate. A hybrid form characterized by its white belly inhabits the eastern Pacific. Other less distinct groupings inhabit other oceans.The species name comes from the Latin word for “long-beaked.”
Spinner dolphins are small cetaceans with a slim build. Adults are 129–235 cm long and weigh 23–79 kg. This species has an elongated rostrum and a triangular or subtriangular dorsal fin. Spinner dolphins generally have three colours, one on the dorsal fin, one on the underside and one on the upper-side. Also, a dark band runs from the eye to the flipper, bordered above by a thin, light line. However, the spinner dolphin has more geographic variation in form and coloration than other cetaceans. In the open waters of eastern Pacific, dolphins have relatively small skulls with short rostra. A dwarf form of spinner dolphin occurs around southeast Asia. In these same subspecies, a dark dorsal cape dims their tripartite colour patterns Further offshore, subspecies tend to have a paler and less far-reaching cape.] In certain subspecies, some males may have upright fins that slant forward.[8] Some populations of spinner dolphin found in the eastern Pacific have backwards-facing dorsal fins, and males can have dorsal humps and upturned caudal flukes.
The spinner dolphin lives in nearly all tropical and subtropical waters between 40°N and 40°S. The species primarily inhabits coastal waters, islands, or banks. However, in the eastern tropical Pacific, spinner dolphins live far from shore. Some studies suggest they use different areas at different times of the year.
The spinner dolphin feeds mainly on small mesopelagic fish, squids, and sergestid shrimps, and will dive 200–300 m to feed on them. Spinner dolphins of Hawaii are nocturnal feeders and forage in deep scattering layers, which contain many species. The dwarf spinner dolphin may feed mostly on benthic fish in reefs and shallow water. Off Oahu, Hawaii, spinner dolphins forage at night and cooperatively herd their prey into highly dense patches. They swim around the prey in a circle and a pair may swim through the circle to make a catch. Spinner dolphins are in turn preyed on by sharks. Other possible predators include the killer whale, the false killer whale, the pygmy killer whale and the short-finned pilot whale. They are susceptible to parasites, and are known to exhibit both external ones like barnacles and remoras as well as internal parasites.
Due to the spinner dolphin foraging and feeding at night, in certain regions, such as Hawaii and northern Brazil, dolphins spend the daytime resting in shallow bays near deep water. Spinner dolphins rest as a single unit, moving back and forth slowly in a tight formation but just out of contact with one another. These resting behaviours are observed for about four to five hours daily. During rest periods, spinner dolphins rely on vision rather than echolocation. At dusk, they travel offshore to feed. They travel along the shore during foraging trips, and the individuals that occupy the same bay may change daily. Some individual dolphins do not always go to a bay to rest; however, in Hawaii, dolphins do seem to return to the same site each trip.
Spinner dolphins live in an open and loose social organization. The spinner dolphins of Hawaii live in family groups, but also have associations with others beyond their groups. Mothers and calves form strong social bonds. Spinner dolphins seem to have a promiscuous mating system, with individuals changing partners for up to some weeks. A dozen adult males may gather into coalitions. Vocalizations of spinner dolphins include whistles, which may be used to organize the school, burst-pulse signals, and echolocation clicks. The spinner dolphin has a 10-month gestation period, and mothers nurse their young for one to two years. Females are sexually mature at four to seven years, with three-year calving intervals, while males are sexually mature at seven to 10 years. Spinner dolphins live for about 20-25 years old. Breeding is seasonal, more so in certain regions than others.
Although most spinner dolphins are found in the deeper waters offshore of the islands, the rest of the Hawaiʻi population has a more coastal distribution. During daytime hours, the island-associated stocks of Hawaiian spinner dolphins seek sanctuary in nearshore waters, where they return to certain areas to socialize, rest, and nurture their young.
They get their name for their spinning jumps, a spinner dolphin comes out of the water front first and twists its body as it rises into the air. When it reaches its maximum height, the dolphin descends back into the water, landing on its side. A dolphin can make two to seven spins in one leap; the swimming and rotational speed of the dolphin as it spins underwater affects the number of spins it can do while airborne. These spins may serve several functions. Some of these functions are believed by experts to be acoustic signalling or communication. Another reason is to remove ectoparasites such as remoras. Dolphins may also make nose-outs, tail slaps, flips, head slaps, “salmon leaps”, and side and back slaps.
The protected status of spinner dolphins are CITES Appendix II and Marine Mammal Protection Act (MMPA) protected throughout its range as well as MMPA depleted in its eastern stock. Tens of thousands of spinner dolphins, mostly eastern and white-bellied varieties, were killed in the 30 years after purse seine fishing for tuna began in the 1950s; The process killed probably half of all eastern spinner dolphins. They have also been contaminated by pollutants such as DDT and PCBs. Spinner dolphins, as with other species affected by ETP tuna purse-seine fishing, are managed nationally by the coastal countries and internationally by the IATTC. The IATTC has imposed annual stock mortality limits on each purse seine and promulgated regulations regarding the safe release of dolphins. The eastern tropical Pacific and Southeast Asian populations of the spinner dolphin are listed on Appendix II of the Convention on the Conservation of Migratory Species of Wild Animals (CMS), since they have an unfavourable conservation status or would benefit significantly from international co-operation organized by tailored agreements. In addition, the spinner dolphin is covered by Memorandum of Understanding for the Conservation of Cetaceans and Their Habitats in the Pacific Islands Region (Pacific Cetaceans MoU) and the Memorandum of Understanding Concerning the Conservation of the Manatee and Small Cetaceans of Western Africa and Macaronesia (Western African Aquatic Mammals MoU). Spinner dolphins are susceptible to disease and two of the recorded diseases within them are toxoplasmosis and cetacean morbillivirus. The number of cases reported however is fairly low in the species.
Spinner dolphins in Hawaii receive multiple daily visits to their near-shore resting grounds, with boats taking people out daily to snorkel and interact with the local dolphin population. Such activities are increasingly coming under criticism on the grounds of possible harm to the dolphins, and efforts are being made both to educate the public in order to minimise human impact on the dolphins, and to bring in regulations to govern these activities. In 2023, 33 swimmers were arrested for reportedly harassing dolphins off the coast of the Big Island of Hawaii. The swimmers reportedly broke federal law by swimming within 45 meters (50 yards) of the dolphins. The ban went into effect in 2021 due to dolphins not getting enough rest during the day to forage for food at night. The swimmers were caught by drone footage pursuing the dolphins as they tried to escape.
We are eager to work with people who run boats to see these animals – provided they are run with due care for the animals. Do get in touch, or fill in a form you will find in ‘List your wild place’ at the top of the page (or click here).