Category: Dolphins and whales

For 150 years, no one had ever seen a full spade-toothed whale. Then two wash up on a beach.

By Ed Yong | November 5, 2012 12:00 pm

For almost 150 years, no one had seen a spade-toothed whale. That’s not to say that the animal had gone extinct – no one had ever seen one alive. The first clue to its existence came in 1872, when Scottish geologist James Hector described an unusual jaw that had been collected from New Zealand’s Pitt Island a year earlier. Two more partial skulls would follow: another from New Zealand’s White Island in 1950 and the other from Chile’s Robinson Crusoe Island in 1986. But still, no one had seen the animal in the flesh.

Then, in December 2010, two of them washed up on Opape Beach in New Zealand.

Read More

NOC, the white whale that tried to sound like a human

By Ed Yong | October 22, 2012 12:00 pm

//

Listen to this recording. It sounds like a drunkard playing a kazoo, but it’s actually the call of a beluga (a white whale) called NOC. Belugas don’t normally sound like that; instead, NOC’s handlers think that his bizarre sounds were an attempt at mimicking the sounds of human speech.

The idea isn’t far-fetched. Belugas are so vocal that they’re often called “sea canaries”. William Schevill and Barbara Lawrence – the first scientists to study beluga sounds in the wild – wrote that the calls would occasionally “suggest a crowd of children shouting in the distance”. Ever since, there have been many anecdotes that these animals could mimic human voices, including claims that Lagosi, a male beluga at Vancouver Aquarium, could speak his own name. But until now, no one had done the key experiment. No one had recorded a beluga doing its alleged human impression, and analysed the call’s acoustic features.

Read More

Why do killer whales go through menopause?

By Ed Yong | September 13, 2012 2:00 pm

Here’s yet another reason why humans are weird: menopause. During our 40s, women permanently lose the ability to have children, but continue to live for decades. In doing this, we are virtually alone in the animal kingdom. From a cold evolutionary point of view, why would an animal continue to live past the point when it could pass on its genes to the next generation? Or put it another way: why don’t we keep on making babies till we die? Why does our reproductive lifespan cut out early?

One of the most popular explanations, first proposed in the 1966, involves helpful grandmothers. Even if older women are infertile, they can still ensure that their genes cascade through future generations by caring for their children, and helping to raise their grandchildren.* There’s evidence to support this “grandmother hypothesis” in humans: It seems that mothers can indeed boost their number of grandchildren by stepping out of the reproductive rat-race as soon as their daughters join it, becoming helpers rather than competitors.

Now, Emma Foster from the University of Exeter has found similar evidence among one of the only other animals that shows menopause: the killer whale.

Read More

Same gene linked to bigger brains of dolphins and primates

By Ed Yong | September 11, 2012 7:00 pm

Every whale and dolphin evolved from a deer-like animal with slender, hoofed legs, which lived between 53 and 56 million years ago. Over time, these ancestral creatures became more streamlined, and their tails widened into flukes. They lost their hind limbs, and their front ones became paddles. And they became smarter. Today, whales and dolphins – collectively known as cetaceans – are among the most intelligent of mammals, with smarts that rival our own primate relatives.

Now, Shixia Xu from Nanjing Normal University has found that a gene called ASPM seems to have played an important role in the evolution of cetacean brains. The gene shows clear signatures of adaptive change at two points in history, when the brains of some cetaceans ballooned in size. But ASPM has also been linked to the evolution of bigger brains in another branch of the mammal family tree – ours. It went through similar bursts of accelerated evolution in the great apes, and especially in our own ancestors after they split away from chimpanzees.

It seems that both primates and cetaceans—the intellectual heavyweights of the animal world—could owe our bulging brains to changes in the same gene. “It’s a significant result,” says Michael McGowen, who studies the genetic evolution of whales at Wayne State University. “The work on ASPM shows clear evidence of adaptive evolution, and adds to the growing evidence of convergence between primates and cetaceans from a molecular perspective.”

Read More

Argentinian gulls are eating whales (or at least bits of whales)

By Ed Yong | July 6, 2012 9:00 am

Photo by Mariano Sironi, Instituto de Conservación de Ballenas, Argentina, via BBC

Like most seagulls, the kelp gull is an opportunist. It will catch fish and other small prey, but it’s not above scavenging at landfill sites. And off the southern coast of Argentina, some kelp gulls have developed a taste for whale.

Between June and December, Southern right whales gather to breed in the waters off Peninsula Valdes in Argentina, and every year, thousands of tourists go out to watch them.  Kelp gulls are watching too. As the whales surface for air, the birds land and rip pieces of skin and blubber form their backs, inflicting gaping wounds up to 20 centimetres long. The whales violently arch their backs to submerge whatever they can below the water, before hurriedly swimming away.

The first of these attacks was documented in 1972, and they have been getting worse. In 1974, just 1 per cent of whales had gull-inflicted wounds. By 2008, 77 per cent of them carried such injuries.

Read More

New sense organ helps giant whales to coordinate the world’s biggest mouthfuls

By Ed Yong | May 23, 2012 1:00 pm

The world’s largest animals have been hiding something. The bodies of the giant rorqual whales—including the blue, fin and humpback—have been regularly displayed in museums, filmed by documentary makers, and harpooned by hunters. Despite this attention, no one noticed the volleyball-sized sense organ at the tips of their lower jaws. Nicholas Pyenson from the Smithsonian Institution is the first, and he thinks that the whales use this structure to coordinate the planet’s biggest mouthfuls.

Read More

Dolphins that help humans to catch fish form tighter social networks

By Ed Yong | May 1, 2012 7:00 pm

In the coastal waters of Laguna, Brazil, a shoal of mullet is in serious trouble. Two of the most intelligent species on the planet – humans and bottlenose dolphins – are conspiring to kill them. The dolphins drive the mullet towards the fishermen, who stand waist-deep in water holding nets. The humans cannot see the fish through the turbid water. They must wait for their accomplices.

As the fish approach, the dolphins signal to the humans by rolling at the surface, or slapping the water with their heads or tails. The nets are cast, and the mullet are snared. Some manage to escape, but in breaking formation, they are easy prey for the dolphins.

According to town records, this alliance began in 1847, and involves at least three generations of both humans and dolphins. Today, there are around 55 dolphins in the neighbourhood, and around 45 per cent of them interact with the fishermen.

Now, Fabio Daura-Jorge from the Federal University of Santa Catarina, Brazil studied Laguna’s dolphins to learn how their unusual collaboration has shaped their social networks. He spent two years taking photographs of the local dolphins, and noting where they travelled and who they were associated with. As is typical for bottlenose dolphins, the Laguna individuals formed a ‘fission-fusion’ society – they all belonged to the same large group, but they had specific ‘friends’ whom they would spend more time with.

The dolphins roughly split into two separate groups, based on their tendency to hunt with humans. Those that co-operated with the fishermen were more likely to spend time with each other than the uncooperative individuals. Likewise, the uncooperative dolphins showed a tendency to stick to their own clique.

One individual even seemed to act as a “social broker”, and spent time with individuals from both groups.

Of the two groups, the human-helpers seemed to form stronger social ties. It is not clear if helping humans means they spend more time together, or vice versa. But certainly, their close associations increase the odds that one dolphin will learn the hunting technique from its peers.

This fits with what we know about bottlenose dolphins. They are extremely intelligent animals and different populations have developed their own quirky foraging traditions by learning from one another. Some use sponges to guard their snouts when they root about the ocean floor for food. Others can prepare a cuttlefish meal by sequentially killing and stripping them.

Daura-Jorge now wants to understand why only some of the dolphins help the fishermen, given that doing so clearly provides them with benefits, and all of them have the opportunity to help. By analysing the dolphins’ genes, he hopes to piece together their family trees, and work out if mothers pass on the behaviour to their calves.

 

Reference: Daura-Jorge, Cantor, Ingram, Lusseau & Simoes-Lopes. 2012. The structure of a bottlenose dolphin society is coupled to a unique foraging cooperation with artisanal fishermen. Biology Letters http://dx.doi.org/10.1098/rsbl.2012.0174

Bonus: There are several cases around the world where dolphins feed on the discarded remains of fish thrown away by humans. But the Laguna animals do far more than that – the fisherman wouldn’t catch any fish at all without their help. A similar alliance takes place half a world away in Burma, where Irrawaddy dolphins also fish cooperatively with humans.

More on dolphin behaviour:

Will we ever… talk to dolphins?

By Ed Yong | March 27, 2012 9:00 am

Here’s the fourth piece from my new BBC column

“What’s that Flipper? The treasure is over there?” So went a typical plotline for the popular TV series featuring the cute, bottlenosed dolphin who could communicate with his human guardians, and who – in the time-honoured fashion – used his animal powers to apprehend criminals.

The idea that animals like Flipper can communicate with humans is not just the preserve of the small and big screen. History is littered with celebrity animals who have communicated with human scientists, with varying degrees of success. Many apes, including Washoe and Nim the chimps, and Kanzi the bonobo, have learned to communicate by using sign language or symbols on a keyboard. Alex, an African grey parrot learned over 100 English words, which he could use and combine appropriately; his poignant last words to Irene Pepperberg, his scientist handler, were “You be good. I love you. See you tomorrow.”

Dolphins hold a particular fascination; we are captivated by their intelligence and beauty, and swimming with dolphins features regularly on lists of things to do before you die. Denise Herzing has a lifetime of such experiences. For the last 27 years, she has been swimming with a group of Atlantic spotted dolphins in Florida as part of the Wild Dolphin Project. She can identify every individual and they, in turn, seem to trust and recognise her. It is a solid foundation for the boldest attempt yet to talk with dolphins.

One-way chat

“Talk” is tricky to define. A SeaWorld trainer who prompts a dolphin to jump for fish is arguably communicating with it. But such simple one-way interactions are a far cry from the conversational world of Dr Doolittle. Here, the dolphin responds, but says nothing intelligible back. Herzing’s vision is much more ambitious – she wants to establish two-way communication with her dolphins, with both species exchanging and understanding information.

The idea of talking to dolphins has a long and chequered history. It was widely publicised in the 1960s by John Lilly, who argued that dolphins have such large brains that they must be extremely intelligent and have a natural language. All we had to do was to “crack the code”. Much of Lilly’s work was highly questionable. He once flooded a house to keep a captive dolphin, instigated failed attempts to teach them spoken English, and even gave the animals LSD (while taking the drug himself). But there is no denying his influence in popularising the idea of two-way dolphin communication. “He said that in a few years, we will have established complex dialogue with them,” says Justin Gregg from the Dolphin Communication Project. “And he was saying that every few years.”

Lilly was right about dolphin intelligence, but not dolphin language. A true language involves small elements that combine into larger chains, to convey complex, and sometimes abstract, information. And there is no good evidence that dolphins have that, despite their rich repertoire of whistles and clicks.

Little less conversation

Wild dolphin communication is hard to study. They are fast-moving and hard to follow. They travel in groups, making it hard to assign any call to a specific individual. And they communicate at frequencies beyond what humans can hear. Despite these challenges, there is some evidence that dolphins use sounds to represent concepts. Each individual has its own “signature whistle” which might act like a name. Developed in the first year of life, dolphins use these whistles as badges of identity, and may modulate them to reflect motivation and mood. This year, a study showed that when wild dolphins meet, one member of each group exchanges signature whistles.

But beyond this, dolphin chat is still largely mysterious. “To communicate with dolphins, we need to understand how they communicate with each other in the natural world,” says psychologist Stan Kuczaj at the University of Southern Mississippi. “We still don’t know basic things like what the units of dolphin communication are. Is a whistle the equivalent of a “word” or a “short sentence”? We don’t know.”

We may not be able to understand them yet, but we know that dolphins can learn to understand us. In the 1970s, Louis Herman taught an invented sign language, complete with basic syntax, to a bottlenose dolphin called Akeakamai. For example, if he made the gestures for “person surfboard fetch”, Akeakamai would bring the board to him, while “surfboard person fetch” would prompt her to carry the person to the board. His experiments showed that dolphins could understand hundreds of words, and how those words could be combined using grammatical rules.

What’s my motivation?

Herman’s work was groundbreaking, but this was still one-way communication. It focused on comprehension, not conversation. In the 1980s, Diana Reiss had more luck by showing that dolphins could use underwater keyboards to make basic requests. When they prodded keys with their snouts, a whistle would play and Reiss gave a reward like a ball. Eventually, the dolphins used the artificial whistles to ask for the associated rewards.

But as conversations go, these were shallow ones. “The dolphins were only really interested in communicating about needs that they had, like a tool they needed or a fish they wanted,” says Kuczaj, who was involved in a similar project at DisneyWorld’s EPCOT Center. “We hoped they would also comment on other things going on in the aquarium but they didn’t.”

It is difficult persuading dolphins to learn some arbitrary signals, like a whistle signifying a ball, and then use them in a social context, admits Gregg. “They don’t seem to run with it the same way that chimps or bonobos have. The big stumbling block is motivation. Dolphins don’t seem to care.”

Herzing disagrees. She notes that captive animals, which often lack stimulation, will respond to systems like the underwater keyboards. She thinks that these experiments disappointed because they were cumbersome. “The dolphins swim very fast and went to where they were requested, but humans are very slow in the water. There wasn’t enough real-time interaction.”

Chat line

Herzing is trying to solve that problem with Cetacean Hearing and Telemetry (CHAT) – a lighter, portable version of the underwater keyboards. It consists of a small phone-sized computer, strapped to a diver’s chest and connected to two underwater recorders, or hydrophones. The computer will detect and differentiate dolphin sounds, including the ultrasonic ones we cannot hear, and use flashing lights to tell the diver which animal made the call.

The CHAT device can also play artificial calls, allowing Herzing to coin dolphin-esque “words” for things that are relevant to them, like “seaweed” or “wave-surfing”. She hopes the dolphins will mimic the artificial whistles, and use them voluntarily. By working with wild animals, and focusing on objects in their natural environment, rather than balls or hoops, Herzing hopes to pique their interest.

Herzing emphasises that her device is not a translator. It will not act as a dolphin-human Rosetta stone. Instead, she wants both species create a joint form of communication that they are both invested in. She hopes that CHAT will tap into the “natural propensity” that dolphins have “for creating common information when they have to interact”. For example, in Costa Rica, distantly related bottlenose and Guyana dolphins will adopt a shared collection of sounds when they come together, using sounds that they don’t use when apart.

As with past projects, all of this depends on whether the dolphins play along. Kuczaj says, “It’s a remarkable challenge because she is working with wild dolphins so they’ve got the option to participate or not.” Here, Herzing has an edge, since the animals know her, and vice versa. “We’ve been observing them underwater every summer since 1985,” she says. “I know the individuals personally – their personalities and relationships. We’ve got a pretty good handle on what they’d be interested in.” Perhaps this combination of cutting-edge technology and old-school fieldwork will finally produce the conversations that have eluded scientists for so long.

Giant squid, what big eyes you have. All the better to spot sperm whales with, my dear.

By Ed Yong | March 15, 2012 12:40 pm

The giant squid sees the world with eyes the size of soccer balls. They’re at least 25 centimetres (10 inches) across, making them the largest eyes on the planet.

For comparison, the largest fish eye is the 9-centimetre orb of the swordfish. It would fit inside the giant squid’s pupil! Even the blue whale – the largest animal that has ever existed – has measly 11-centimetre-wide eyes.

So why the huge leap in size? Why does the giant squid have a champion eye that’s at least twice the size of the runner-up?

Dan-Eric Nilsson and Eric Warrant from Lund University, Sweden, think that the squid must have evolved its eye to cope with some unique challenge that other animals don’t face. They suggest that the world’s biggest eyes evolved to spot one of the world’s biggest predators – the sperm whale.

Read More

When meeting up at sea, bottlenose dolphins exchange name-like whistles

By Ed Yong | February 28, 2012 7:00 pm

When we meet a group of strangers, one of the first things we’ll do is to introduce ourselves by name. Nicola Quick and Vincent Janik from the University of St Andrews have found that groups of bottlenose dolphins do something similar. When they meet one another in the wild, they exchange “signature whistles”. These whistles are unique to each individual, and they’re strikingly similar to human names. And it seems that they’re a standard part of a dolphin’s meet-and-greet etiquette.

Read More

NEW ON DISCOVER
OPEN
CITIZEN SCIENCE
ADVERTISEMENT

Discover's Newsletter

Sign up to get the latest science news delivered weekly right to your inbox!

Not Exactly Rocket Science

Dive into the awe-inspiring, beautiful and quirky world of science news with award-winning writer Ed Yong. No previous experience required.
ADVERTISEMENT

See More

ADVERTISEMENT
Collapse bottom bar
+

Login to your Account

X
E-mail address:
Password:
Remember me
Forgot your password?
No problem. Click here to have it e-mailed to you.

Not Registered Yet?

Register now for FREE. Registration only takes a few minutes to complete. Register now »