Spinner Dolphin

Spinner dolphin

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 family Delphinidae 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).

Arctic fox

Arctic fox

The Arctic fox is a white fox which lives throughout the Arctic region, and is common throughout the Arctic biome. Other names include white fox, polar fox or snow fox.

It is a similar size to other foxes, although generally more rounded, so as to loose as little weight as possible.

The Arctic fox preys on many small creatures such as lemmings, voles, ringed seal pups, fish, waterfowl, and seabirds. It also eats carrion, berries, seaweed, and insects and other small invertebrates.

Natural predators of the Arctic fox are golden eagles, Arctic wolves, polar bears, wolverines, red foxes, and grizzly bears. Having said this, they are also keen scavengers and seem to get alarmingly close to these animals on relatively regular occasions. in places where they occur, rodents such as lemmings can form a large part of an arctic fox families diet. In areas where their range overlaps with red foxes, they often build bigger dens with more exits, so as to be able to escape. One of the issues with reduced snow cover, is the fact that red foxes can seize range formerly used by Arctic foxes.

During much of the year, there is as much as a 90-100 degree difference between the internal temperature of the fox and the air temperature. When inactive, they will curl up into a ball, tucking in all extremities to preserve heat as much as possible.

Primarily monogamous, a pair of arctic foxes are required in order to raise their cubs. In areas where predation is higher, arctic foxes change their behaviour. Here they are often far more promiscuous, possibly so that there are more adults who think the young is theirs and therefore more help for protection, should one of the true parents get killed.

They are the only fox with fur on their feet, so as to avoid even more heat loss. It appears to have originated out of foxes from the Tibetan Plateau.

There are 4 recognized subspecies (beyond the common one)


    • Bering Islands Arctic fox, V. l. beringensis

    • Greenland Arctic fox, V. l. foragoapusis

    • Iceland Arctic fox, V. l. fuliginosus

    • Pribilof Islands Arctic fox, V. l. pribilofensis

African wild dog escape in the West Midlands Safari Park and what are they going to do?

African wild dog are some of the most efficient hunters on the planet. Significantly smaller than lion or leopard, often even than cheetah, African wild dogs are astoundingly efficient when they come to hunting, with one of the highest percentage success rates in the animal kingdom. Due to their need for huge reserves, to have a viable population, it is not unusual for them to spread into unprotected land.

12 of the African wild dogs in the West Midlands Safari Park got out of their enclosure. Before they could be caught, they had killed six Persian Fallow deer and 10 Barbary sheep. Their escape was not down to negligence or incompetence, but down to storm Clara.

Wild dogs are small predators compared to Lions or Leopards, but are highly effective. They have a higher success rate than any other savannah top predator. Although in the wild they would run if approached by humans, when escaped from a zoo they will be scared and so their behaviour would be unpredictable

However because of this need for large amounts of space they are seriously endangered. This means that more than many other animals In order to ensure their long-term survival as substantial population of captive wild dogs need to be built up in case they need to be reintroduced to the wild.

It should be noted that despite the damage, the wild dog whenever anywhere they were capable of attacking people. It should also be noted That generally wild dog are not a danger to humans.

Due to their need for large areas of land, there is only thought to be about 1400 wild dog left in the whole of Africa.

Beaver trial reintroduction in the UK has a problem when one of the animals escapes

Reintroducing beavers into the UK would be a very sensible move. As a natural part of our ecosystem the fact that they are no longer there has an impact. Apart from the substantial reduction in flash floods that will occur should beavers be reintroduced across the UK, they also have a huge impact on biodiversity and the general river ecosystem as well as acting as a filter meaning that the water further downstream is substantially cleaner virtually eliminating all farm runoff.

However at the moment all British schemes to do with reintroducing beavers consist of putting the beavers into relatively small enclosures and then watching their impacts and how well they do.

Continue reading “Beaver trial reintroduction in the UK has a problem when one of the animals escapes”

Nairobi National Park: a wilderness refuge that borders a capital City, what could go wrong?

Nairobi National Park is world-renowned as it is a wildlife Park that is right on the edge of a capital city (4 miles from the city centre). It is Kenya’s first National Park formed in 1946, it is not a large Park covering only around 45 square miles, so it forms part of migrating roots so what time to the year has large populations. Is particularly known for it rhino population, and while it is not a big 5 preserved as there are no elephants it does have cheetah which is rare for reserve so small.

However the issue with having a wild area this close to the city centre is that on occasion the Lions leave the park. When this happened and they come into contact with local residents it is often that the result is sad. A resident living near the park was unfortunately killed by a lion that left. The park is surrounded by an electric fence but this is not not always working and fences the really able to keep in large mammals permanently.

The Lion has killed around 30 dogs and other livestock in the area, and has clearly lost its fear of humans. If it is not possible to move this lion to reserve where it will not come into Direct contact with humans then this lion must be put down- a lion with no fear of humans sees us only as a source of food and will not stop coming back.

I have talked in the past about lion management and the ability to make man eating highly unlikely, all usual methods will fail though with a reserve like this. Reserves like this are important, but we need to find ways for locals to live alongside them safely.

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