Marine scientists have long suspected that humpback whales’ incredible agility comes from the bumps on the leading edges of their flippers. Now Harvard University researchers have come up with a mathematical model that helps explain this hydrodynamic edge. The work gives theoretical weight to a growing body of empirical evidence that similar bumps could lead to more-stable airplane designs, submarines with greater agility, and turbine blades that can capture more energy from the wind and water.

Prototypes of wind-turbine blades (see image below) have shown that the delayed stall doubles the performance of the turbines at wind speeds of about 17 miles per hour and allows the turbine to capture more energy out of lower-speed winds. For example, the turbines generate the same amount of power at 10 miles per hour that conventional turbines generate at 17 miles per hour. The tubercles effectively channel the air flow across the blades and create swirling vortices that enhance lift.

WhalePower has also shown in demonstrations that tubercle-lined blades on industrial ceiling fans can operate 20 percent more efficiently than conventional blades can, and they do a better job at circulating air flow in a building. The results were dramatic enough to convince Canada’s largest maker of ventilation fans to license the design, which will appear in a new line of products scheduled for release at the end of April.

The Harvard study reaches the same conclusion. “It is possible that the lessons learned from humpback-whale flippers will soon find their way into the design of special-purpose wings, hydrofoils, as well as wind turbine and helicopter blades.”

B) In a widely reported story a dolphin was observed leading two pygmy sperm whales to safety that had become stranded on a beach off the cost of New Zeland.

From the BBC news site:

“The disoriented mother and calf had resisted attempts to herd them out to sea, and kept restranding on the beach, to the point where Smith said the pair would likely have to be killed.

Then Moko appeared, and came right up to the whales before leading them out to sea.

“Quite clearly the attitude of the whales changed when the dolphin arrived on the scene. They responded virtually straight away,” Smith said.

“The dolphin managed in a couple of minutes what we had failed to do in an hour and a half.”

Smith said the whales had not been sighted again in the area.”

“A dolphin appeared to “talk” to two stranded whales before leading them to safety. How common is inter-species communication?

“Before the bottlenose dolphin turned up, the beached pygmy sperm whales were in clear distress.

But when Moko arrived at Mahia beach on the east coast of New Zealand’s North Island, their mood changed and they followed him to safety.”

Similar in size and colour to a bottlenose dolphin, it is possible that a pygmy sperm whale might have signals in common with a dolphin, just as different species of dolphins are known to share signals which might theoretically allow a form of basic inter-species communication.

But just as it’s possible that Moko the dolphin and the stranded whales shared a signal, it is also possible that the whales just saw a vaguely similar creature and followed it.”

Other examples of communications between species are:

“Ants protect the habitat of leaf lice and in return get a sugar excretion to eat, he says. They interact chemically and physically – the ants massage the leaf lice by secreting a small amount of the sugary food they are after.

And honeyeater birds guide larger animals, like badgers, to a beehive for them to do the “dirty work” of breaking it so they can gain access.

The communication takes the form of the honeyeater flying around the badger to get its attention then performing a call, flying towards the beehive and checking the badger is following. If it isn’t, the honeyeater flies back to try again.”

“The vervet monkey listens to the alarm calls of the superb starling to find out what kind of predators are around.

Then the monkey follows an avoidance strategy accordingly, so if it’s an aerial predator they duck under trees or if it’s a leopard they run up trees. This way they improve their chances of survival.”

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