DOLPHINS IN CAPTIVITY AND DOLPHIN LANGUAGE

We have all heard the sounds dolphins can make when they seem to communicate with each other or with their human trainers. We also know that they can navigate with their eyes covered using echolocation.

Research has shown that dolphin echolocation is so good that they can detect a 75 mm object at distances up to 100 m away.

The debate over dolphin language goes on and will until we can 'crack' the code. In the mean time there is mounting evidence that they do communicate ideas in a sophisticated way.

Scientists have shown that the same species of dolphin living in the English Channel stick to either the French or English side and never mix. Is it possible they stay apart because they don't speak the same language?




At the moment we believe they have vocabularies similar to apes complete with food sounds, danger sounds, and 'seeking' sounds. There are many more sounds that we don't understand at all. 

Dolphins can assemble short strings of sounds the way we make sentences. We are also pretty sure that they use distinct sounds to represent themselves; they have a name and this is recognized by other dolphins.




Noise probably isn't a problem for dolphins in captivity but it is for wild dolphins. In Datai Bay where I work, I sometimes hear dolphin whistles but they are often drowned out by the sounds of trawlers and heavy ships passing.

Lots of ambient noise would be like trying to chat at a rock concert. This could make communication and echolocation pretty difficult. More about this in another post.

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CAPTIVE DOLPHIN REMEMBERS FRIENDS AFTER 20 YEARS

In an amazing experiment with a captive dolphin in Florida Dr. Bruck played a recording of the signature whistle of a 2 year old female to a 25 year old male. The male and female had been together 20 years earlier when the male was only 4 years old. The result? The captive male recognuized the whistle of his female companion after 20 years separation.

So, what does this mean for wild dolphins?

In the wild, dolphins live for about 20 years but many live as long as 45 years. That means that most dolphins are able to remember the "names and identities" through signature whistles of many of the other dolphins they build bonds with.

On the 'memory score card' dolphins rank in the top one or two non-human memory stakes. Only the elephant is said to be able to remember for periods of 20 years or so and we don't know if elephants can remember all the elephants they befriend along the way.

Why dolphins' social memories persist so long is unclear. Dr. Bruck says that dolphins exhibit sophisticated social connections that follow a "fission-fusion" model. Dolphins may separate from one group and "fuse" with other groups many times over. Such relationships could have required a growth in memory capacity to avoid social conflicts. But it's also possible that memory is just one facet of the advanced mind that evolved in dolphins for other reasons.

"Why do they need this kind of memory? I'm not sure they do," Bruck said. "The cognitive abilities of dolphins are really well developed, and sometimes things like this are carry-along traits. But to test whether this kind of social memory capacity is adaptive, we would need more demographic data from multiple populations in the wild to see if they experience 20-year separations."

The emergence of advanced memory in marine mammals as well as in humans shows that in evolution, "there are lots of ways to get from point A to point B," Bruck said. "It's nice to see this kind of ability in a non-primate, as this is a great example of convergent evolution."

"So far no one has been able to test what signature whistles signify in a dolphin's mind. We know they use these signatures like names, but we don't know if the name stands for something in their minds the way a person's name does for us," Bruck said. "We don't know yet if the name makes a dolphin picture another dolphin in its head."

For his next round of research, Bruck said, "That's my goal -- show whether the call evokes a representational mental image of that individual.

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DOLPHIN MEMORY AND INTELLIGENCE

New research reveals that dolphins can recognize the whistles of old "tank mates" after a separation of 20 years.This is the longest social memory recorded for any species other than humans.

The remarkable memory  is another indication that dolphins have a level of cognitive ability comparable to only a few other species, including humans, chimpanzees and elephants. Dolphins' talent for social recognition may be even more long-lasting than facial recognition among humans. This is because human faces change over time but the signature whistle that identifies a dolphin remains stable over many decades.

"This shows us an animal operating cognitively at a level that's very consistent with human social memory," said Jason Bruck, who conducted the study and received his Ph.D. in June 2013 from the University of Chicago's program in Comparative Human Development. His study is published in the current issue of the Proceedings of the Royal Society of London B.

To establish how well dolphins could remember their former companions, Bruck collected data from 53 different bottlenose dolphins at six facilities, including Brookfield Zoo near Chicago and Dolphin Quest in Bermuda. The six sites were part of a breeding consortium that has rotated dolphins and kept records on which ones lived together, going back decades.

"This is the kind of study you can only do with captive groups when you know how long the animals have been apart," Bruck said. "To do a similar study in the wild would be almost impossible."

"Signature whistles" offer means to test memory

Other studies have established that each dolphin develops its own unique signature whistle that appears to function as a name. Researchers Vincent M. Janik and Stephanie L. King at Scotland's University of St. Andrews reported earlier this year that a wild bottlenose dolphin can learn and repeat signatures belonging to other individuals, and answer when another dolphin mimics its unique call.

Bruck played recordings of signature whistles to dolphins that had once lived with the animals that made the calls. Determining whether the dolphins recognized their old companions required a comparison of how they responded to familiar calls versus calls belonging to dolphins they had never met.

Bruck would play recording after recording of signature whistles that the target dolphins had never heard before. His initial studies showed that these "dolphins get bored quickly listening to signature whistles from dolphins they don't know." Once they were habituated to the unfamiliar calls, Bruck would play a recording of an animal that he knew the target dolphin had lived with.

The familiar calls often would perk up the dolphins and elicit an immediate response.

"When they hear a dolphin they know, they often quickly approach the speaker playing the recording," Bruck said. "At times they will hover around, whistle at it, try to get it to whistle back."

To check that the response was the result of recognition, Bruck also would play a test recording of an unfamiliar bottlenose that was the same age and sex as the familiar animal. All the behavior was scored according to how quickly and to what degree the animals responded.

A clear pattern emerged in the data: Compared with unfamiliar calls, dolphins responded significantly more to whistles from animals they once knew, even if they had not heard the calls in decades.

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DOLPHINS IN CAPTIVITY; DO THEY THINK?

When we say "think" we are talking about cognitive ability. And like just about everything else in the world, we tend to measure cognitive ability in our own terms.

In terms of brain size, dolphin brains are significantly larger than our own. If we relate brain size to body mass then we slip into the lead and dolphins come in second. The question is what do dolphins do with all that neural material?

Neuro scientist, Dr Lori Marino, says that some dolphin brains exhibit features correlated with complex intelligence. They have a large expanse of neo-cortical volume that is more convoluted than our own, extensive insular and cingulated regions, and highly differentiated cellular regions.

Dr. Marino went on to say, "Dolphins are sophisticated, self-aware, highly intelligent beings with individual personalities, autonomy and an inner life. They are vulnerable to tremendous suffering and psychological trauma."





While presenting information at the American Association for the Advancement of Science conference (AAAS) in San Diego, she spoke against keeping dolphins in captivity. "Our current knowledge of dolphin brain complexity and intelligence suggests that these practices are potentially psychologically harmful to dolphins and present a misinformed picture of their natural intellectual capacities," Marino says.

Because we are unable to communicate with dolphins, it is difficult to assess their cognitive or thinking ability. Instead scientists use indicators of 'levels' of ability. One indicator is self awareness.





Dr. Marino found that dolphins were able to recognize themselves as distinct from other dolphins in a mirror. This ability is found in higher primates like ourselves and in elephants.

Can dolphins think?

The answer is a definite yes. We don't know what they think about but can guess that their thought processes are complex and relatively sophisticated.

If they think about their social group, hunting, and navigation then they might not spend a lot of time thinking about confinement versus a life in the ocean.

If they have sophisticated thoughts and can compare an aquarium with the ocean then they could be quite miserable in captivity.

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DOLPHINS KEPT IN CAPTIVITY; DO THEY HAVE FEELINGS?

I spent several years working from an island field station on the Great Barrier Reef. Although most of my time was spent working long hours with fish along the reef slope, I came to recognize a group of three bottlenose dolphins that regularly passed through my study site. They never came close but seemed interested in what I was up to. I found that if I ignored them and hammered small steel pins into the bottom (used as markers), the dolphins would come up behind me and look over my shoulder. If I turned, they were gone in a flash.

I’ve also spent hours cleaning windows in an oceanarium when I was going through university. Lots of things swam around behind me then but I feel that the dolphins were either bored or had little interest because of the regularity of my job with the brush.

Now I am working in Datai Bay and often see Chinese Humpback or White Dolphins. Again they are curious but incredibly shy.

The Chinese White Doplhin

Let’s look at a single question based on what we know about dolphins today;

Do dolphins have emotions and feelings like our own?

If we look at dolphins anatomically, we see that they have a well developed limbic system. The limbic system is a collection of neural material that is part of the ancient mammalian brain. It is common to mammals.

The limbic system supports a number of functions including emotion, behavior, motivation, long-term memory and olfaction. In humans it has a lot to do with our emotional life and is vital to the formation of memories.

But as a scientist, I have to ask the question, “Do we know if the limbic system in dolphins performs the same role as in humans?” The answer is we don’t know.

We do know that memory for dolphins are very important since they live in a world with only visual and olfactory clues for navigation. We might assume that as long lived animals, the amount of memory stored would be large.

A pod of wild dolphins must use a good memory map for navigation.

We also know that dolphins ‘express’ emotion. I say this because we can’t really know what they are feeling; we can only imagine our feeling in the same situation.

An example would be the loss of an offspring. More advanced mammals seem to behave as we do and mourn. Again this is an interpretation. Less advanced mammals and even many non-mammals may seem to do the same.

Do dolphins enjoy human contact?

Unfortunately, the scientific facts just aren’t in yet. From my perspective dolphins have emotions but not at the human level. They show curiosity similar to other advanced mammals but again from my perspective they are not as emotional or curious as monkeys and apes (just my opinion!).

My next post will look at what we know about dolphin intelligence and ask;

“Do dolphins think?"

 



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IN SEARCH OF THE "RIGHT" WHALE

whalE-Mail from Jeff

Hey Gerry,

Only have a minute but wanted to let you know HOW MUCH FUN IT IS to be part of the Team. Let me know what you need and I'll try and come up with it. One of the things that we've been developing up here in the Bering Sea and has worked very well for us is the use of Sono Buoys. They're basically a hydrophone that has directional and transmitting capabilities. We'll drop a couple at low altitudes from the plane about 10 miles apart and then listen in real time to the animal’s vocalizations. We can hear animals vocalizing up to 15 miles away from the buoys and depending on or altitude we can listen to the buoys up to 40 miles away. Once we hear a Right Whale we can triangulate between the buoys and usually can come up with a direction of where the animal may be. It's very cutting edge and pretty cool stuff. Thought you might be interested in this for other dolphin projects. Gotta run! Thanks again and hope to talk to you soon! Cheers, Jeff 

Jeff has been involved in the Right Whale Surveys for the last few years. He works from aircraft, speed boats, and even huge balloons. He has been working on the North Pacific Right Whales which grow up to 18 m long and weigh up to 100 tonnes; the largest of the three Eubalaena Right Whales.

Hey Jeff, is this the ‘right’ one?

They are called "right whales" because whalers preferred them. They were the “right” ones to catch because they floated when killed and were close to shore. Being “right” meant that their populations were decimated over a short time as the result of intensive harvesting.

Dropping Sono Buoys.

Adults today are between 11–18 m long and weigh 60–80 tonnes. The body is extremely stocky measuring about 10 m in circumference for a large animal. The tail fluke is also broad (up to 40% of body length).

 Jeff gets his camera wet.

There are two populations of the North Pacific Right Whale. The population in the eastern North Pacific/Bering Sea is extremely low, and may number under 50 individuals (Jeff’s last count was 17!). A larger western population of 200-300 is found in the Sea of Okhotsk. Because of these extremely low numbers, the two northern right whale species are the most endangered of all the large whale species. Some researchers believe they are the most endangered animals in the world and calculate that their falling numbers will bring about extinction in the 22^nd century.

Estimated numbers (2006):

North Atlantic Right Whales  (North Atlantic)…….....400-450

North Pacific Right Whales  (Eastern North Pacific)…50-100

North Pacific Right Whales  (Sea of Okhotsk)…….…200-300

Right Whale killed by ship’s propeller (Wikipedia).




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Porpoises; The Quiet Killing

The Guardian reported (4^TH April, 2014) that Japan's biggest online retailer, Rakuten, will stop their whale meat and dolphin meat sales by the end of April after the International Court of Justice ordered Japan to immediately halt its annual whale hunts in the southern ocean.

 Offshore whaling in the Southern Ocean


Rakuten said it had asked sellers to cancel sales of whale meat products on its website “in accordance” with the ICJ ruling. Monday’s verdict in the Hague. It should be pointed out that it did not cover whale meat sales within Japan, which are legal, or the country’s slaughter of whales in the north-west Pacific and in its own coastal waters.

The decision by Rakuten comes soon after the UK-based Environmental Investigation Agency (EIA) exposed the company as the world’s biggest online retailer of whale products and elephant ivory.

Until recently Rakuten's website carried more than 1,200 advertisements  for whale products, according to the EIA and the Humane Society International.

Sadly, the lack of whale meat from the Southern Ocean is only likely to raise demand for the locally caught porpoises and dolphins. We have all heard about the killing at Taiji and the documentary, The Cove, but it is dwarfed by the slaughter at Iwate, Japan.

Dall's Porpoises in the slaughter shed.

Iwate is about 600 km north of Taiji and is the source of the meat from Dall's Porpoise. The killing here has been more than seven times the number of Taiji animals but it went largely unnoticed by the public. In fact it is the largest hunt for marine mammals on the planet.

Recently, the numbers of Dall's Porpoises killed was declining but the new International Court of Justice ruling is about to change all that. before the restriction on taking whales outside of Japan, it was estimated that from November, 2012 to April, 2013 about 1,200 porpoises were taken ( Environmental Investigation Agency (EIA)).But this was well below the horrific 9,129 Dall's Porpoises reported slaughtered in 2009-2010.

When porpoise meat was used as a substitute for the more expensive whale meat, the Iwate catch nearly exceeded the annual quota of 16,000 porpoises. In 1988, two years after the International Whaling Commission (IWC) stopped the killing of large whales, more than 40,000 Dall’s Porpoises were killed.

So what is a Dall's Porpoise?

Named after the American naturalist,  they are the largest of six species of porpoise. Porpoises are not the same as dolphins and are more closely related to the Belugas. Adult males reach as much as 200 kg and like other porpoises are incredible swimmers. They aren't as trainable as dolphins and aren't suited to oceanarium life; their destiny is food for the table.

Hunting coastal whales is an old business in Japan but it was expanded after WW II because of a shortage of protein. Japanese sent whaling ships into the Southern Ocean. Since that time whale meat has taken a premium place in the Japanese diet.

The new restrictions will now cause a shift to the older coastal fishing areas to fill the lucrative gap. Fishermen will go to sea in small boats armed with razor-sharp harpoons and spear the hapless Dall's Porpoises in their thousands.

Unlike Taiji, the killing goes on at sea and the porpoises are landed in the early light. the butchering is carried out ashore and away from prying eyes.

I can see how the hunt began in decades past. I can see how whaling developed after the War when people were short of food. I can not understand why it continues in a nation that describes itself as civilized and advanced and which no longer has a need other than money. And I can not understand the lack of interest by groups and governments that advocate for these wonderful animals.

Mahatma Gandhi said, "The greatness of a nation can be judged by the way its animals are treated." We will soon see what happens during the killing season in Iwate, Japan.

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THE EDGE OF EXTINCTION; THE BLUE WHALE TRAGEDY

 Blue Whales evolved from the Indohyus, about 50 million years ago. The closest relative today is the hippopotamus. Up until the early 20^th century their numbers would have been fairly stable. The largest population was in the Antarctic, numbering approximately 240,000 (range 202,000 to 311,000).

With the advent of ‘mechanized’ whaling, they were hunted almost to extinction until protected by the international community in 1966. A 2002 report estimated there were only 5,000 to 12,000 Blue Whales worldwide.

Blue Whales tend to live alone or with one other individual but it is not known how long these associations last. Larger feeding groups of 30-50 may form when food is abundant but there does not seem to be the communication typical of a true pod. 

Blue Whale hunting was banned in 1966 but continued illegally in the USSR until the 1970’s. By that time 330,000 Blue Whales had been killed in the Antarctic, 33,000 in the rest of the Southern Hemisphere, 8,200 in the North Pacific, and 7,000 in the North Atlantic. By the time the killing stopped, only about 1 out of every 1000 Blue Whales (0.15%) survived.

Ships carrying whalers are no longer a threat to the Blue Whale but ships carrying cargo are. This summer four were run down by ships further depleting a population that is on the edge of extinction. Ship collisions result from whales and cargo using the same sea lanes for their journeys.

Whale migration:

Blue Whales do a lot of traveling and to better understand how their migrations conflict with shipping, a new generation of scientists is taking to the seas.

Today’s ‘hunters’ attach GPS tags to the Blue Whales to track their positions and record data as they travel. The high-tech devices are attached to the whale in the form of a small harpoon that is imbedded in the blubber.

The GPS tag will only transmit its data above the water when the whale surfaces to take another breath. They spend only about 10% of their time at the surface when they expel a rush of air and spray that can be seen two km away; there she blows!

National Geographic photo used for educational purposes.

Interested in swimming with dolphins? Check out some of the other posts in this blog.


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