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

Australian Humpback dolphin

Australian Humpback dolphin

While there is no clear scientific estimate for the population of this dolphin, its population is certainly a few thousand. They are found between Northern Australia and Southern New Guinea. It was only described in 2014. It is most closely related to the Chinese humpback dolphin.

They suffer incidental capture in gill nets as other dolphins do. What is clear, is that more study is needed to fully understand the situation.

Southern right whale

Southern right whale

The Southern right whale, like the other species in its genus, was hunted incredibly close to extinction. As a wide ranging species, when the population fell possibly as low as 300 in 1920 – so this species was saved by its low numbers, not the ban on hunting in 1935, which likely would have come too late.

It should be noted that Russia ignored this role until 1970. During these 35 years, many were killed by Russia, and when I say many, we are talking hundreds of thousands of species that everyone else was trying to save.

The population is now thought to be around 13,600, which is an impressive increase in around 100 years, of around 45 times increase. The historical population is estimated to lie between 55,000 and 70,000.

So where can they be watched? Far and away, the best known place to see them is Hermanus in South Africa, where around 100 whales congregate each year. I have seen them here, and it is a relatively easy species to see if you are in the right place. They are found from around around 20 degrees South to 65 degrees South around the world. In the past New Zealand was a fantastic place to watch them, and in recent years they returned for the first time in 80 years. They are also naturally seen in big numbers around Australia, and places like Patagonia.

Links will appear below as we make them

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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 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

UK government backsliding on environment? two clues and an how is Australia doing

The government of the UK has been talking the talk for a significant period of time. At times they have suggested some policies that should move in the right direction, unfortunately they have often reversed these relatively quickly.

An example of this is the governments green housing grants – advertised as intending to improve the UK housing to work more efficiency. Unfortunately, it was cut too soon, had perhaps 1% of the investment needed to get the whole job done, and proved to merely be a handout to building companies.

So what has caught my eye this time?

  1. A suggestion that oil and gas can be part of the UK net zero strategy? No carbon capture scheme (CCS) has ever worked large scale, and furthermore, none have captured all of the pollution. Far from moving away to fossil fuels, the UK intends to create a new wave of oil and gas exploration – and trying to justify this by suggesting that all the carbon will be caught. Of 13 CCS projects carried out recently, a study found that – 1 was cancelled before start, 2 failed, 7 underperformed, which leaves only 3 to have succeeded. A success rate of 23%. Looking back, out of the 39 million tonnes of carbon dioxide caught worldwide through CCS, more than 70% was used for Enhanced Oil Recovery – in other words of the 3 projects that performed, less than 1 of them would have actually helped to reduce carbon emissions. SO ARE WE ACTUALLY TRYING TO CUT EMISSION IN THE UK?
  2. The UK has just scrapped a top climate diplomatic role. As roles like this are one of the simple ways that a country shows what its priorities- countries who are paying attention will be saying this means that the UK is no longer concentrating on global warming. The FCDO (Foreign, Commonwealth and Development Office) said the climate crisis remained of “utmost importance” – while this may be true ?!? it certainly sends the wrong signal.

How is Australia doing?

We need to start reducing emissions at some point – this seems self evident, if we are to meet any of our carbon reduction goals. In Australia the labour and Greens have done a deal that might actually improve policy covering Australia’s biggest polluters.

While the new ideas is complicated, it changes the safeguard mechanism to take the country closer to meeting the goal of cutting greenhouse gas emissions to net zero by 2050.

While Australia’s government has been talking the right talk recently, the Australian newspapers have published fear mongering by the fossil fuel companies – forcing up prices, put domestic gas supply at risk, destroy jobs and “kill foreign investment” in the coal industry, The Daily Telegraph published a story which claimed the changes to the safeguard mechanism would risk $96 billion of energy projects – and that should be seen as “coal hard facts”.

One coal boss told the Australian that the changes to the safeguard mechanism were built on a political objective to push a “base demonisation of fossil fuels” that would threaten Australias role as a “Reliable energy exporter” for the region. This is so completely illiterate of the science as to be laughable (if it was not for the fact that many people will listen).

A former editor of the Australian Chris Mitchel wrote that Environmental journalists and the “left media” were “in a frenzy” over the most recent release from the UNs climate panel – he claimed that they are missing the elephant in the room, that climate change has failed to arrive.

Despite what many in the fossil fuel industry wish to claim, it is not hard to see climate change, indeed it is all around us. Mitchell claimed that the world would not, and could not do without fossil fuels – though if you don’t believe that the climate has been effected, then this is an easier position to reach.

What is clear, is that while the voices against doing what i needed to leave a world we wish to for future generations, have not shut up, in most instances they are not winning.

Has Australia actually appointed a climate change authority member who actually wants to do the right thing?

Australia is likely to loose a great deal if climate change continues in a big way. This is because Australia already has a large part of the country unbearably hot. If the temperature increases another 2-5 degrees these areas might well become impossible to survive within.

This is why it is so strange that Australia is so backwards in this respect.

Currently, Australia gets a great deal of money by selling coal abroad. This is because Australia is incredibly rich in coal. As a result they are keen to be able to put off zero carbon as long as possible as they will loose this income.

Professor Lesley Huges is a climate specialist, that has just been appointed to the Australia climate change authority and she has quite rightly stated that 2050 net zero is not good enough. Encouragingly, though she has also said that the new government was showing a willingness to listen to science. The Climate change minister has appointed 3 new members after it was suggested that the authority was to heavily weighted in the direction of business and fossil fuels (if there are too many representatives from this part of the market, then concerns about global warming are likely to get less voice, as fossil fuel companies know they only have a finite length of time to make money from resources that are likely to be banned in the future).

Continue reading “Has Australia actually appointed a climate change authority member who actually wants to do the right thing?”

Could the Platypus go extinct soon?

The Platypus was such a wierd looking animal, many of the original scientists that studied specimens sent back to the UK, looked for sewing marks – they believed that it must be several creatures joined together. Even 20 years after its discovery, scientists were still arguing about whether it was real. The anatomist Robert Knox claimed if was a “freak imposture”, and that ”the scientific [community] felt inclined to class this rare production of nature with eastern mermaids and other works of art.” This was not only due to its weird appearance, but several other fake animals that had come to light in recent times.

Yet it was not,

A wild Platypus

To be sure, it is a mammal which perhaps stretches the definition more than most. It lays eggs, has a ducks beak, but feeds its young on milk. It is one of the many oddities that live in Australia.

Unfortunately it is facing local extinction, in many places across its range, and has lost a quarter of its range in the last 30 years..

This is a species that could quietly slip towards extinction without being noticed – being shy, nocturnal and not splashing, they are rarely seen. Most people who do not see one, might suggest that they simply did not get lucky.

There are a range of threats that are pushing them towards extinction. Water extraction from rivers and creeks, the building of dams and weirs, as well as river bank erosion. Increasing regularity of droughts also threaten their long-term survival as their homes become too shallow – allowing feral cats and foes to attack them.

They are capable of living alongside humans – the video above is in the Suburbs of a city, but as pollution increases they often disappear.

The lead author of the study concludes that the Platypus is not facing complete extinction, but local extinction in many different parts of Australia.

New Australian study on reef in a no fishing zone, shows what can happen when reefs are untouched by humans

The reef in question – The Rowley Shoals, are an isolated archipelago about 260km off Australia’s north west coast.

What was found was incredible. Between its protection from fishing, its location and the shape of the reef it has sustained species long lost elsewhere.

Species of giant fish like humphead Maori wrasse and humphead Parrotfish (both growing to over 1.5m were a regular sight, despite the fact that globally they are threatened with extinction. Of particular excitement, across the long study, there was no discernible change in the quantity of these fish – even as they were seen less and less regularly elsewhere.

Efforts must be made to maintain reefs like this, in their unblemished state. These reefs are far more capable of dealing with environmental changes, and hopefully one day there will be a need to reseed reefs in more accessible parts of the world.

Recent evidence suggests that dingoes arrived in Australia 1500 years later than first thought: why is this important and should it give us more courage in repatriating Tasmanian devils to the mainland

While the dingo made look like part of the native fauna of Australia, that is not the case. They were bought there by aboriginal people. 

the dingo may look like a domestic dog, there has been little or no interbreeding for 4000 years with other dogs that were domesticated
Continue reading “Recent evidence suggests that dingoes arrived in Australia 1500 years later than first thought: why is this important and should it give us more courage in repatriating Tasmanian devils to the mainland”
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