Tag: Japan

Indo-pacific bottlenose dolphin

Indo-Pacific Bottlenose dolphin

The Indo-Pacific bottlenose dolphin is a species of Bottlenose dolphin. This dolphin grows to 2.6 m long, and weighs up to 230 kg . It lives in the waters around northern Australia , South China, the Red Sea, and the eastern coast of Africa. Its back is dark grey and its underside is lighter grey or nearly white with grey spots. The Indo-Pacific bottlenose dolphin is usually smaller than the Common bottlenose dolphin, has a proportionately longer Rostrum, and has spots on its belly and lower sides. It also has more teeth than the common bottlenose dolphin — 23 to 29 teeth on each side of each jaw compared to 21 to 24 for the common bottlenose dolphin.

Much of the old scientific data in the field combine data about the Indo-Pacific bottlenose dolphin and the common bottlenose dolphin into a single group, making it effectively useless in determining the structural differences between the two species. The IUCN lists the Indo-Pacific bottlenose dolphin as “near threatened” in their Red List of endangered species.

Until 1998, all bottlenose dolphins were considered members of the single species Tursiops truncatus. In that year, the Indo-Pacific bottlenose dolphin was recognized as a separate species. Both species are thought to have split during the mid-Pleistocene, about 1 million years ago. Some evidence shows the Indo-Pacific bottlenose dolphin may actually be more closely related to certain dolphin species in the Delphinus (genus), especially the “Atlantic spotted dolphin”, than it is to the common bottlenose dolphin. However, more recent studies indicate that this is a consequence of reticulate evolution (such as past hybridization between Stenella and ancestral Tursiops and incomplete lineage sorting, and thus support truncatus and T. aduncus belonging to the same genus. Burrunan dolphin T. (aduncus) australis has been alternately considered its own species, a subspecies of T. truncatus, or a subspecies of T. aduncus. Following the results of a 2020 study, the American Society of Mammologists presently classifies it as a subspecies of T. aduncus. The same study delineated 3 distinct lineages within T. aduncus which could each be their own subspecies: an Indian Ocean lineage, an Australasian lineage, and the Burrunan dolphin. The Society for Marine Mammalogy does not recognize the Burrunan dolphin as a distinct species or subspecies, citing the need for further research. Indo-Pacific bottlenose dolphins are very similar to common bottlenose dolphins in appearance. Common bottlenose dolphins have a reasonably strong body, moderate-length beak, and tall, curved dorsal fins; whereas Indo-Pacific bottlenose dolphins have a more slender body build and their beak is longer and more slender. 

Indo-Pacific bottlenose dolphins feed on a wide variety of fish Cephalopod, Squid, researchers looked at the feeding ecology of Indo-Pacific bottlenose dolphins by analysing the stomach contents of ones that got caught in the gillnet fisheries off Zanzibar, Tanzania.  Indo-Pacific bottlenose dolphins live in groups that can number in the hundreds, but groups of five to 15 dolphins are most common. 

In some parts of their range, they spend time with the common bottlenose dolphin and other dolphin species, such as the humpback dolphin. The peak mating and calving seasons are in the spring and summer, although mating and calving occur throughout the year in some regions. Gestation period is about 12 months. Calves are between 0.84 and 1.5 Meters, and weigh between 9 and 21kg. The calves are weaned between 1.5 and 2.0 years, but can remain with their mothers for up to 5 years, some mothers will give birth again, shortly before the 5 years are up. 

In some parts of its range, this dolphin is subject to predation by sharks. 

Its lifespan is more than 40 years. Indo-Pacific bottlenose dolphins located in Shark Bay, Australia, have been observed using sponges as tools in a practice called “sponging”. A dolphin breaks a marine sponge off the sea floor and wears it over its rostrum, apparently to probe substrates for fish, possibly as a tool. Spontaneous ejaculation in an aquatic mammal was recorded in a wild Indo-Pacific bottlenose dolphin near Mikura Island, Japan, in 2012. Indo-Pacific bottlenose dolphins have been observed to swim near and rub themselves against specific types of corals and sponges. A team of scientists followed up on this behaviour and discovered metabolites with antibacterial, antioxidative, and hormonal activities in the corals and sponges, suggesting that they might be used by the dolphins to treat skin infections. its near-shore distribution, though, makes it vulnerable to environmental degradation, direct exploitation, and problems associated with local fisheries. 

The major predators of this species are typically sharks, and may include humans, killer whales, and sting rays. In the early 1980s, many were deliberately killed in a Taiwanese driftnet fishery in the Arafura Sea, off north western Australia. Large-mesh nets set to protect bathers from sharks in South Africa and Australia have also resulted in a substantial number of deaths. Gillnets are also having an impact, and are a problem throughout most of the species’ range.

These small cetaceans are commonly found in captivity, causing conservation concerns, including the effects of removing the animals from their wild populations, survival of cetaceans during capture and transport and while in captivity, and the risks to wild populations and ecosystems of accidentally introducing alien species and spreading epizootic diseases, especially when animals have been transported over long distances and are held in sea pens.

Bottlenose dolphins are the most common captive cetaceans on a global scale. Prior to 1980, more than 1,500 bottlenose dolphins were collected from the United States, Mexico, and the Bahamas, and more than 550 common and 60 Indo-Pacific bottlenose dolphins were brought into captivity in Japan. By the late 1980s, the United States stopped collecting bottlenose dolphins and the number of captive-born animals in North American aquaria has increased from only 6% in 1976 to about 44% in 1996. South Korea, in the 2010s, environmental groups and animal protection groups led a campaign ko:2013 to release southern bottlenose dolphins illegally captured by fishermen and trapped in Jeju Island.

In a study on three populations of Indo-Pacific bottlenose dolphins in Japan, the characteristics of acoustic signals are believed to be affected by the acoustic environments among habitats, and geographical variation in animal acoustic signals can result from differences in acoustic environments; therefore, the characteristics of the ambient noise in the dolphins’ habitats and the whistles produced were compared. Ambient noise was recorded using a hydrophone located 10 m below the surface and whistles were recorded by using an underwater video system. The results showed dolphins produced whistles at varying frequencies with greater modulations when in habitats with less ambient noise, whereas habitats with greater ambient noise seem to cause dolphins to produce whistles of lower frequencies and fewer frequency modulations. Examination of the results suggest communication signals are adaptive and are selected to avoid the masking of signals and the decrease of higher-frequency signals. They concluded ambient noise has the potential to drive the variation in whistles of Indo-Pacific bottlenose dolphin populations.

Small, motorized vessels have increased as a source of anthropogenic noise due to the rise in popularity of wildlife viewing such as whale watching. Another study showed powerboat approaches within 100 m altered the dolphin surface behaviour from traveling to milling, and changed their direction to travel away from the powerboat. When the powerboat left the area and its noise ceased, the dolphins returned to their preceding behaviour in the original direction.

In Shark Bay, Western Australia, on dolphin behavioural responses showed significant changes in the behaviour of targeted dolphins were found when compared with their behaviour before and after approaches by small watercraft. Dolphins in the low-traffic site showed a stronger and longer-lasting response than dolphins in the high-traffic site. These results are believed to show habituation of the dolphins to the vessels in a region of long-term vessel traffic. However, when compared to other studies in the same area, moderated responses, rather, were suggested to be because those individuals sensitive to vessel disturbance left the region before their study began. Although these studies do show statistical significance for the effects of whale-watching boats on behaviour, what these results mean for long-term population viability is not known. The Shark Bay population has been forecast to be relatively stable with little variation in mortality over time. The Indo-Pacific bottlenose dolphin populations of the Arafura and the Timor Sea are listed on Appendix II of the Convention on the Conservation of Migratory Species of Wild Animals “Bonn Convention”. 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. The Indo-Pacific bottlenose dolphin is also covered by Memorandum of Understanding for the Conservation of Cetaceans and Their Habitats in the Pacific Islands Region Adelaide Dolphin Sanctuary “Marine protected area”  in the Australian state of South Australia Gulf St Vincent, which was established in 2005 for the protection of a resident population of Indo-Pacific bottlenose dolphins.

When we have links for viewing these species, they will appear below video and the news section

Narrow-ridged (or East Asian) finless porpoise

Narrow ridged (east Asian) finless Porpoise

This species is native to the East China Sea, Yellow Sea, and the seas around Japan. The Yangtze finless was originally thought to be a subspecies of this porpoise, though further study showed its differences to be greater than that (hence it now being recognized as a separate species). The east asian finless porpoise is a subspecies of the narrow ridged finless porpoise (the above picture is one of these).

Growing to 2.27m at most, and 72kg, though most are smaller.

They generally stay in water 50m deep or less, and mostly stay close to shore (though not always – it has been spotted over 100km from land).

The biggest threat to them is habitat degradation and pollution. The population has fallen by 50% in the last 3 generations.

They have been kept in captivity in Japan, Indonesia and China. A total of 94 are thought to have been held. Unfortunately these do not live long, and of all of the pregnancies that have occurred in captivity, only 2 resulted in a love birth and this did not survive for long.

Beluga Whale

Beluga Whale

Beluga whales are only found in the arctic and sub-arctic oceans. They are one of just 2 species in their family Monodontidae, and are unique in their genus of Delphinapterus. It is also known as the white whale, the sea canary and the Melon-head (though the melon-headed dolphin is a species of its own, so this name may cause some confusion.

Adaptions it has for the Arctic, include the fact that it is white in colour, allowing it to blend into the white world more effectively, and the fact it has no dorsal fin, which allows it to swim very close to the ice sheet above.

Growing up to 5.5m in length and up to 1600kg they are a pretty large dolphin. Generally, living in groups of around 10, in the summer, they group together in their hundreds or thousands.

The worlds population is thought to be around 200,000, Some populations move from the edge of the ice cap, into rivers in warmer areas, while others stay around the ice caps year round. Groups of people in both USA and Russia have hunted them for many centuries.

Hunting is not controlled, and as such the drop in population could happen quite fast. Russia and Greenland have killed enough to drop their local population significantly, though thankfully not Alaska or Canada.

They do also have their natural predators in both the killer whale and the Polar bear.

They are the most commonly kept cetaceans in the world, with around 300 in captivity. Japan, USA, Ukraine, Canada, China and Russia as well as a few more.

There are 22 populations around the world, these vary from 39,000 down to as little as 500. The total population is around 200,000. While this number is large, the number hunted is definitely not sustainable. There is also no care to distinguish the different populations, which suggests that sub-populations could be pushed to extinction without any care.

Below, you will find a clip from a bbc documentary which features this species. Below this, is a list of any mentions that the beluga whale has had on this site. Below this, I will list any opportunities to see this species in the wild. Click on list your wild place, to list yours. It takes just a few minutes, and costs nothing – we only charge a commission on any business we send your way.

Pygmy Sperm Whale

 The Pygmy sperm whale is one of just two species from the Superfamily Kogiidae, the other one being the Sperm whale. They are seen very rarely, with the majority of the knowledge about them, coming from carcasses that wash up on the beach. It was first described in 1834 based on a skull that washed up on the coast of france in 1784 (50 years earlier). While originally placed in the same genus as the sperm whale, it was moved to its own genus Kogia, as it is actually a species which is half way between the dolphins and the sperm whale.

They grow to around 3.5m, which is smaller than many dolphin species.

It has a far smaller brain than the sperm whale (even by comparison size) which my explain why it has such a lot more simple social life.

Pygmy sperm whales are found throughout the tropical and temperate waters of the Atlantic, Pacific, and Indian Oceans, though there are also seen regularly off Russia. Fossils in Japan, Italy South Africa have been found, suggesting that they were more widely spread. The problem is, that seen rarely at sea, and with most of what we know about coming from carcasses, we have little idea if dead and dying animals behave differently to healthy ones.

Seen rarely, I have been unable to find out how long they can hold their breath, though as the sperm whale can hold its breath for 90 minutes, so its likely that the pygmy sperm whale is also an impressive breath holder – this would explain why they are seen so rarely.

Sea-Lions

An encounter with almost any wild animal can be something you remember for years. This sealion that came out of the sea on the beach in New Zealand is no different

Sea-lions

There are 6 living species of sea-lion, and 1 extinct. As the interest in these species grows and the links become unwieldy i will split out the separate species, but for the time being I will just have one page for them all – help it to be necessary to split them as soon as possible. 

Sea-lions are pinnipeds with external ear flaps, long fore-flippers, the ability to walk on all fours, short and thick hair, and a big chest and belly. The sea-lions the 6 living species shown below (the Japanese sea-lion is extinct) in five genera. Their range extends from the subarctic to tropical waters of the global ocean in both the Northern and Southern Hemispheres, with the notable exception of the northern Atlantic Ocean. They have an average lifespan of 20–30 years.[2] A male California sea-lion weighs on average about 300 kg (660 lb) and is about 2.4 m (8 ft) long, while the female sea-lion weighs 100 kg (220 lb) and is 1.8 m (6 ft) long. The largest sea-lions are Steller’s sea-lions, which can weigh 1,000 kg (2,200 lb) and grow to a length of 3.0 m (10 ft). Sea-lions consume large quantities of food at a time and are known to eat about 5–8% of their body weight (about 6.8–15.9 kg (15–35 lb)) at a single feeding. Sea-lions can move around 16 knots (30 km/h; 18 mph) in water and at their fastest they can reach a speed of about 30 knots (56 km/h; 35 mph).[3] Three species, the Australian sea-lion, the Galápagos sea-lion and the New Zealand sea-lion, are listed as endangered.

Steller sea-lion
Australian sea-lion
California sea-lion
Galápagos sea-lion
New Zealand sea-lion
South American sea-lion

Steller Sea-lion are found on the land of North America and Asia that circle the north pole (map below, credit NOAA). 

They are predated by killer whales, though sleeper sharks and great whites sometimes take young. They eat a variety of foods, include various fish species, as well as octopus and squid. They are fast swimmers, capable of diving to 1500feet, and staying under for 16 minutes

During breeding season, males fight to control a stretch of beach, and females move freely to the place they favour. 

Status: population has fallen 70-80% since the 1970s and so are listed as endangered, around 46,000 individuals, though in recent years, the Eastern population has grown at around 3% a year (in 2013 this lead to its removal from the US endangered species list)

 

Australian Sea-lion is the only endemic pinniped found in Australia.

They can make a variety of calls, with mothers and young able to pick up each others call in the chaos of a breeding beach. There are currently 66 recognized breeding beaches, though 42% of pups are bred on just 4 of these beaches.

While rare, a bite can require hospitalisation. In both the 1930s and 1960s they were recorded as feeding on little penguins, and this still happens today. Other food includes a variety of fish and even small sharks, in turn, they are hunted by great white sharks and killer whale (orca).

Population was 14370 in 2010 though by 2014 it had fallen to just 6500 mature individuals, though current estimates are 11,200 suggesting a rebound. Still it is clear that they need particular efforts for their conservation. Despite their (relatively) close ranges, the Australian and New Zealand sea-lions do not appear to be closely related. They are considered vulnerable.

California Sea-lion Are found on the west coast of north America. On this map, the navy blue marks the breeding rance, while the light blue shows the total range that they can be found in. It should be noted, that previously the Japanese and Galapagos sealion were both considered subspecies of the Californian species, but no longer. They can stay healthy, for a time, in fresh water, and have been seen living for a while in Bonneville dam – 150 miles inland.

They see (mostly in blue/green) and hear well, as well as being able to sense nearby, with their whiskers. They generally eat fish, squid and occasionally clams. They have been seen cooperating with other sealions, or indeed dolphins porpoises and sea-birds in their hunting techniques, though exploitation is also common.

There are 5 relatively distinct populations. Several sealions have reached Japanese waters in recent years, and this is the most likely origin, as such  it could return to Japan on its own. 

It is considered least concern with 238,000-241,000 individuals and increasing over time.

Galapagos Sea-lions Found on all of the Galapagos Islands, as well as (in smaller numbers) on Isla de la Plata, which is just 40km from Puerto López a village in Ecuador. There have also been recorded sightings on the Isla del Coco which is 500km southwest of Costa Rica (and 750km from the Galapagos). These are not regular, and so have been considered vagrant. It is of course possible that historically they roamed here, but we cannot say.

They are the smallest species of sea-lion, and can often be seen gliding through the water, or sunbathing on the beach. They measure 1.5m-2.5m and weigh between 50 and 400kg.

Much of their diet is made up of sardines. Interaction with humans is usually negative, and feral dogs often form packs, and can then attack the sealions.

The population tends to bounce between 20,000 and 50,000 and they are currently classed as endangered

 

New Zealand Sea-lion (formerly known as the Hooker sealion) is native to south island, though before 1500 it is thought that it was also found on north island. They tend to breed on Subarctic islands of Auckland and Campbell (99% of the pups are born in these islands). In 1993, sealions started breeding on South Island again for the first time in 150 years.

Genetic evidence suggests that until 1300-1500 there was a mainland subspecies, which was wiped out by the Mauri’s and has been replaced by members from the sub-Antarctic population.

As well as eating fish and crustations, they will take new Zealand fur seals as well. They are hunted by great white sharks, and in a survey 27% of adults had scars from near misses. While south American sealions are hunted by orca (with them famously beaching to catch them) they do not appear to do this around New Zealand. After the birth of their pup, females move inland as much as 2km to avoid males, storms and even parasites.

They are thought to number 12,000 making them the rarest sealion. They are also the most distinct being part of the Genus Phocarctos, and are listed as endangered.

 

South-American Sea-lion

Also known as the Southern sealion or the Patagonian sealion. They have been recorded going as far north as Ecuador, though not yet breeding there. They eat fish, as well as squid and octopus, and have even been observed predating penguins, pelicans and South American fur seals.

Males set up territories, but after the arrival of females switch to protecting them. Having said this, one population in Peru have a different set-up where males perform, and females choose a mate, and are free to move freely. This may be in result to the warmer climate, which means the females make regular trips into the sea.

The total population is estimated at 265,000. They are declining in Patagonia (Argentina) and the Falklands but increasing in Chile and Uruguay. In the 2013 El nino many Peruvian sealions died. They are still regularly killed by fishermen, both for damaging equipment and stealing fish.

They are listed as least concern

 

As we gain contacts each picture above will become a link to a page for the specific species – for now, all species will be looked after by this page. If you are a wildlife guide or live nearby and want to be able to host (as a hotel or B&B or campsite) and would like to be listed do get in touch. Our aim, is to give people all the information and links on one page, so that they can book everything in one go – making it easy, and therefore more people undertaking these sort of trips.

Sea-lions can be specifically searched out, but it is also possible to have a surprise encounter with one.

One of my most memorable encounters with any wildlife, is an encounter with a New Zealand sealion.  We had simply gone for a walk on the beach, and at some point, we saw the sea-lion coming out of the sea. This huge male slowly made its way towards us, and when about 10m away it lay down in the sand, threw sand all over itself and went to sleep.

To return to the Pinniped page click here

Japanese raccoon dog

The Japanese raccoon dog (also called the Tanuki) is a species that is native to Japan. Mainly nocturnal, although known to be active during daylight. They vocalize by growling or with groans which can sound like domestic cats – they also arch their back (like cats) when trying to intimidate other animals, however it trying to show submissions they behave like other canids by lowering their body to the ground or showing their stomach in submission.

Japanese racoon dog

Social groups are usually limited to breeding pairs, but before pairing off, racoon dogs often form groups until this happens.

Usually monogamous, 4-6 pups are born after 9 weeks. They are looked after in the den for a month, and outside the den for a further month. Their wild lifespan is aound 7-8 years with captive specimens having reached 13 years.

They have sharp claws and have been observed usinig these to climb a tree, so as to forage for fruit and berries.

The Japanese raccoon dog is mainly nocturnal, but they are known to be active during daylight. They vocalize by growling or with groans that have pitches resembling those of domesticated cats. Like cats, the Japanese raccoon dog arches its back when it is trying to intimidate other animals; however, they assume a defensive posture similar to that of other canids, lowering their bodies and showing their bellies to submit.

Usually, social groups are limited to a breeding pair, but individual Japanese raccoon dogs may stay in a group of non-paired individuals until they find a mate.[5]

The species is predominantly monogamous. The breeding period for the species is synchronized between females and males and lasts between February and April. A litter (typically with 4–6 pups) is born after a gestation period of 9 weeks. The parents look after their pups at a den for around a month, and then for another month after the pups leave the den.

Japanese raccoon dogs live for 7–8 years in the wild and have reached the age of 13 in captivity.

They have been observed to climb trees to forage for fruits and berries, using their curved claws to climb.

They have been introduced to northern Europe where they are considered to be a pest.

Racoon dog

Raccoon dog (Nyctereutes procyonoides)

The common raccoon dog (also known as the (Chinese or Asian racoon dog, to distinguish it from the Japanese racoon dog)is a species which is found in east Asia. Although named for its facial markings, it is not closely related to raccoons and, although part of the dog family, it is more closely related to the fox.

This animal has been widely introduced in Europe due to regular escapes from fur farms.

Common raccoon dogs are omnivores that feed on insects, rodents, amphibians, birds, fish, reptiles, molluscs,  crabs, sea urchins, human garbage, carrion, and eggs, as well as fruits, nuts, and berries.

Wolves predate them, and eat many in the spring. In Russia, wolves can account for as much as 2/3 of the deaths. Other animals like badgers and lynx will kill them, but generally do not go out of the way to do so. A range of birds of prey also target them.

They are the only canid to hibernate. There are around 4 subspecies. The Japanese racoon dog was thought to be a subspecies until recently when it was elevated to being its own species. They are one of the species that is thought to be have spread covid, and there are other illnesses that their introduction has caused to arrive in new countries.

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