Showing posts with label biology. Show all posts
Showing posts with label biology. Show all posts

Tuesday, February 15, 2011

To Talk With Aliens, Learn to Speak With Dolphins


(My story on today's Wired Science.)

The Kepler Space Telescope announced a new bonanza of distant planets this month, reconfirming that solar systems, some possibly hosting life, are common in the universe.

So if humanity someday arrives at an extraterrestrial cocktail party, will we be ready to mingle? At the Wild Dolphin Project in Jupiter, Florida, researchers train for contact by trying to talk with dolphins.
Behavioral biologist Denise Herzing started studying free-ranging spotted dolphins in the Bahamas more than two decades ago. Over the years, she noticed some dolphins seeking human company, seemingly out of curiosity.

“We thought, ‘This is fascinating, let’s see if we can take it further,’” Herzing said. “Many studies communicate with dolphins, especially in captivity, using fish as a reward. But it’s rare to ask dolphins to communicate with us.”

Dolphins have large, sophisticated brains, elaborately developed in the areas linked to higher-order thinking. They have a complex social structure, form alliances, share duties and display personalities. Put a mirror in their tank and they can recognize themselves, indicating a sense of self.

When trained, they have a remarkable capacity to pick up language. At the Dolphin Institute in Hawaii, Louis Herman and his team taught dolphins hundreds of words using gestures and symbols. Dolphins, they found, could understand the difference between statements and questions, concepts like “none” or “absent,” and that changing word order changes the meaning of a sentence. Essentially, they get syntax.

Some tantalizing studies even suggest dolphins share their own language (see sidebar, “Easier Language Through Math”). All are qualities we’d hope to see in an alien, and no daydream of contact is complete without some attempt at communication. Yet with dolphins, our attempts have involved teaching them to speak our language, rather than meeting in the middle.

Herzing created an open-ended framework for communication, using sounds, symbols and props to interact with the dolphins. The goal was to create a shared, primitive language that would allow dolphins and humans to ask for props, such as balls or scarves.

Divers demonstrated the system by pressing keys on a large submerged keyboard. Other humans would throw them the corresponding prop. In addition to being labeled with a symbol, each key was paired with a whistle that dolphins could mimic. A dolphin could ask for a toy either by pushing the key with her nose, or whistling.

Herzing’s study is the first of its kind. No one has tried to establish two-way communication in the wild.

“This is an authentic way to approach this, she’s not imposing herself on them,” said Lori Marino, the Emory University biologist who, with Hunter College psychologist Diana Reiss, pioneered dolphin self-recognition studies. “She’s cultivated a relationship with these dolphins over a very long time and it’s entirely on their terms. I think this is the future of working with dolphins.”

For each session, the researchers played with the dolphins for about half-an-hour, for a total of roughly 40 hours over the course of three years. They reported their findings of this pilot study in the December issue of Acta Astronautica.

Herzing’s team found that six dolphins, all young females, were interested in the game, and would come to play when the game was on. Young males were typically less social and less interested in humans. “This is when the females have a lot of play time,” Herzing said, “before they are busy being mothers.”

To Herzing’s surprise, some of her spotted dolphins recruited bottlenose dolphins, another species, to the game. This shows their natural curiosity, Herzing said. In the wild, dolphins communicate across cetacean species lines, coordinating hunting with other dolphins and even sharing babysitting duties.

Herzing found the study sessions were most successful when, before playing, the humans and dolphins swam together slowly and in synchrony, mimicked each other and made eye contact. These are signs of good etiquette among dolphins. Humans also signal their interest in someone with eye contact and similar body language. Perhaps these are universal — and extraterrestrial — signs of good manners.

Before we hope to understand extraterrestrials, then, perhaps we should practice with smart animals right here on Earth. Astronomer Laurance Doyle of the SETI Institute was struck by this thought at a recent conference.

“From the way the presenter was speaking, I thought he was going to announce that he had found a signal of extraterrestrial intelligence,” Doyle said. “We’ve been waiting for this for years, but I thought, ‘We’re not ready!’  We can’t even speak to the intelligent animals on Earth.”

Image: Two Atlantic spotted dolphins in the wild. (Ricardo Liberato)

See Also:

Citations: “SETI meets a social intelligence: Dolphins as a model for real-time interaction and communication with a sentient species.” By Denise L. Herzing. Acta Astronautica, Vol. 67 December 2010.

“Information theory, animal communication, and the search for extraterrestrial intelligence.” By Laurance R. Doyle, Brenda McCowan, Simon Johnston and Sean F. Hanser. Acta Astronautica, Vol. 68, February-March 2011.
 

Saturday, January 29, 2011

Seahorse Shape Explained as Stealth-Attack Adaptation

  
According to a new explanation of seahorse shape, those distinctive S-curve bodies let them reach further than straight-bodied ancestors.

Compared to tube-shaped pipefish, their closest relatives, seahorses extend their snouts an extra 30 percent. The difference is only a few millimeters, but for animals with a strike range of a centimeter or two, it’s a big advantage.

“This makes them stealthier and sneakier hunters,” said Lara Ferry, an Arizona State University ecomorphologist who co-authored the study, published Jan. 25 in Nature Communications. “Their prey is less likely to spot them coming, and they are less likely to miss a meal.”

To test the link between shape and hunting ability, Ferry’s team created a computer model predicting the movements of seahorses and pipefish. By tweaking the features of the model fish, they could estimate how body curvature affected range. They verified their results with high-speed video of seahorses and pipefish feeding.

The videos were needed, Ferry said, because the naked eye can’t see seahorses feed. They’re among the fastest eaters known.

“From the time they spot prey and open their mouth, to the time the shrimp is completely devoured, is only four milliseconds,” said Ferry.

Seahorses rely on stealth attack because they’re poor swimmers. While most fish, pipefish included, swim towards their prey, seahorses hide in sea grasses or corals, hang on with a prehensile tail, and wait for tiny shrimp to float by. To prepare for a strike, they tense their muscles and — like a stretched sling-shot — snap forward. (Watch video from Nature’s website.)

Seahorses are also unusual for being monogamous, and are among the only species in which males bear young.

(Read the original post and see more seahorse photos on Wired.com.) 

Saturday, January 22, 2011

Gallery on Wired Science: 8 Beautiful Bioluminescent Creatures From the Sea

Atolla, a deep sea jelly fish. Image Steve Haddock, MBARI.

While a handful of land animals can create their own light, homemade luminescence is the rule rather than the exception in the open ocean's dark waters.

Researchers estimate that between 80 and 90 percent of deep-dwelling animals are bioluminous, creating light by mixing the pigment luciferin with luciferase, the enzyme that makes it glow. The light tends to green and blue, colors that travel far in seawater. Glowing helps attract mates, lure prey or confound predators.

Many of these animals live thousands of meters deep and are difficult for scientists to find and study. Here are some of the prettiest — and strangest — glowing creatures of the seas.

Check out the rest at Wired Science.

Wednesday, June 10, 2009

Plenty more fish in the sea?


Article I wrote for the OMII-UK newsletter:

Once thought to be an endless source of bounty, rampant over-fishing around the globe has caused world fish stocks to plummet, with some of our favourite species hovering near collapse. The effects of over-fishing are being exacerbated by global climate change, which changes the distribution of species and the location of biodiversity hotspots. Under these conditions, good fisheries management is crucial. But how can stocks be controlled if we don’t know their location and numbers? A new grid-based tool, AquaMaps, looks like it could provide the answer.

Read the full article.