National Geographic Daily News
A dolphin with a spinal deformity mills with sperm whales.

A bottlenose dolphin, with an S-shaped spinal deformity, is seen here rubbing against a sperm whale.

Photograph courtesy Alexander Wilson and Aquatic Mammals

Linda Poon

National Geographic News

Published January 23, 2013

In 2011, behavioral ecologists Alexander Wilson and Jens Krause of the Leibniz-Institute of Freshwater Ecology and Inland Fisheries in Germany were surprised to discover that a group of sperm whales (Physeter macrocephalus)—animals not usually known for forging bonds with other species—had taken in an adult bottlenose dolphin (Tursiops truncatus).

The researchers observed the group in the ocean surrounding the Azores (map)—about 1,000 miles (1,600 kilometers) off the coast of Lisbon, Portugal—for eight days as the dolphin traveled, foraged, and played with both the adult whales and their calves. When the dolphin rubbed its body against the whales, they would sometimes return the gesture.

Among terrestrial animals, cross-species interactions are not uncommon. These mostly temporary alliances are forged for foraging benefits and protection against predators, said Wilson.

They could also be satisfying a desire for the company of other animals, added marine biologist John Francis, vice president for research, conservation, and exploration at the National Geographic Society (the Society owns National Geographic News).

Photographs of dogs nursing tiger cubs, stories of a signing gorilla adopting a pet cat, and videos of a leopard caring for a baby baboon have long circulated the Web and caught national attention.

A Rare Alliance

And although dolphins are known for being sociable animals, Wilson called the alliance between sperm whale and bottlenose dolphin rare, as it has never, to his knowledge, been witnessed before.

This association may have started with something called bow riding, a common behavior among dolphins during which they ride the pressure waves generated by the bow of a ship or, in this case, whales, suggested Francis.

"Hanging around slower creatures to catch a ride might have been the first advantage [of such behavior]," he said, adding that this may have also started out as simply a playful encounter.

Wilson suggested that the dolphin's peculiar spinal shape made it more likely to initiate an interaction with the large and slow-moving whales. "Perhaps it could not keep up with or was picked on by other members of its dolphin group," he said in an email.

Default

But the "million-dollar question," as Wilson puts it, is why the whales accepted the lone dolphin. Among several theories presented in an upcoming paper in Aquatic Mammals describing the scientists' observations, they propose that the dolphin may have been regarded as nonthreatening and that it was accepted by default because of the way adult sperm whales "babysit" their calves.

Sperm whales alternate their dives between group members, always leaving one adult near the surface to watch the juveniles. "What is likely is that the presence of the calves—which cannot dive very deep or for very long—allowed the dolphin to maintain contact with the group," Wilson said.

Wilson doesn't believe the dolphin approached the sperm whales for help in protecting itself from predators, since there aren't many dolphin predators in the waters surrounding the Azores.

But Francis was not so quick to discount the idea. "I don't buy that there is no predator in the lifelong experience of the whales and dolphins frequenting the Azores," he said.

He suggested that it could be just as possible that the sperm whales accepted the dolphin for added protection against their own predators, like the killer whale (Orcinus orca), while traveling. "They see killer whales off the Azores, and while they may not be around regularly, it does not take a lot of encounters to make [other] whales defensive," he said.

24 comments
Kristin Nicole
Kristin Nicole

Orcas LOVE eating baby sperm & grey whales; its a favorite dish of several Orca pods.  They will spend as much as 6 hours taking turns chasing down the mother/calf until the calf succumbs to exhaustion.  Dolphins are designed to hear much higher frequencies than most whale species (they "speak" to each other in these high frequency sounds).  While this dolphin may have a disadvantage from its spine, it can hear distant Orcas much better than the Sperm Whales could, therefor alerting the group to danger much sooner.  Orcas are not whales, they are the largest and smartest dolphin species in the world.  They have been known to kill other dolphin species just for sport or to show dominance/power.....exactly like humans because when you are a top predator, you become arrogant to others around you.  By itself, a lone dolphin that cant keep up with its fast-swimming relatives would be a target for Orcas, who prey upon any weakened marine life (they arent called killers for no reason; they are the top predators in their world).  Both the dolphin and Sperm Whales benefit from this unusual yet amazing grouping :D

Maymuna Kabir
Maymuna Kabir

Ok, if we assume that the sperm whales forged an alliance to keep killer whales at bay... how could a deformed bottlenose dolphin stand up to a killer whale?
Besides, sperm whales are so much bigger than killer whales... why would they need added protection in the first place?

Rose Campbell
Rose Campbell

 You tell us to do something for the dolphins but what? Help me please. What can we do? Who do we right to with our objection and outrage? It sickens me to think of we arrogant humans are doing to dolphins and elephants, both intelligent species> Can't people imagine it would be similar to another species slaughtering a group of humans? Just because WE don't speak their language does NOT give us the right to write them off as dumb fish and massacre them. Why does Japan still do this? It's the 21st century not the 15th. We have so much more knowledge now about the other species we share this planet with you would think we would have developed more respect for others. No. Humans are far too greedy, arrogant and selfish. I'm embarrassed to admit the ones doing the slaughtering are my own kind. How can we let it continue?

Rose Campbell
Rose Campbell

You tell us to do something for the dolphins but what? Help me please. What can we do? Who do we right to with our objection and outrage? It sickens me to think of we arrogant humans are doing to dolphins and elephants, both intelligent species> Can't people imagine it would be similar to another species slaughtering a group of humans? Just because WE don't speak their language does NOT give us the right to write them off as dumb fish and massacre them. Why does Japan still do this? It's the 21st century not the 15th. We have so much more knowledge now about the other species we share this planet with you would think we would have developed more respect for others. No. Humans are far too greedy, arrogant and selfish. I'm embarrassed to admit the ones doing the slaughtering are my own kind. How can we let it continue?

Caroline Johnson
Caroline Johnson

If you like dolphins please help end the slaughter which is being streamed via live video in Taiji, Japan at this very moment, their slaughter is being done under the cover of tarpaulin because of the global outrage - the sea turns red with their blood and they kill 23,000 a year those they don't kill they kidnap for Seaworld and the like, if you want to see dolphins and whales watch them from a boat in the ocean not a man made prison!

http://taiji.ezearth.tv/

Please don't just like videos like this story do something to protect them from man's greed:

http://www.facebook.com/SeaShepherdCoveGuardiansOfficialPage

Juan Marcial Gaytan
Juan Marcial Gaytan

It's an incredible story!!... Every day the species show us they have the capacity of take care with others species!!... They are amicable too. We have the responsibility of preserve the planet and all the species!!...

Joe Marshall
Joe Marshall

Any idea how the dolphin gets enough food to stay alive?

Timothy Lal
Timothy Lal

Awww Im glad the poor little guy was able to find some fiends

Doris Thomas
Doris Thomas

I took some amazing footage a couple of days after Wilson. It contains pics and an incredible video of one of these cachalots taking the dolphin carefully between it's jaws. Surch in youtube for " Sperm Whales and a deformed Bottlenose Dolphin off Lajes (Pico/Azores)" - I supported Wilson with my files to continue his study.

Allen Wayne
Allen Wayne

Since one of the researches to discover this alliance and friendship in Wilson, I suggest we call the Dolphin Wilson.  It fits, remember Wilson from Castaway with Tom Hanks!?  Wilson... it's perfect!  Lost and still loved.  Come on Who didn't cry when he floated away!

John M.
John M.

Could the whales be threatening to harm the dolphin if he tries to leave? Could they be bullying him?

Kristin Nicole
Kristin Nicole

@Maymuna KabirOrcas LOVE eating baby sperm & grey whales; its a favorite dish of several Orca pods.  They will spend as much as 6 hours taking turns chasing down the mother/calf until the calf succumbs to exhaustion.  Dolphins are designed to hear much higher frequencies than most whale species (they "speak" to each other in these high frequency sounds).  While this dolphin may have a disadvantage from its spine, it can hear distant Orcas much better than the Sperm Whales could, therefor alerting the group to danger much sooner.  Orcas are not whales, they are the largest and smartest dolphin species in the world.  They have been known to kill other dolphin species just for sport or to show dominance/power.....exactly like humans because when you are a top predator, you become arrogant to others around you.  By itself, a lone dolphin that cant keep up with its fast-swimming relatives would be a target for Orcas, who prey upon any weakened marine life (they arent called killers for no reason; they are the top predators in their world).  Both the dolphin and Sperm Whales benefit from this unusual yet amazing grouping :D

Steve Hughes
Steve Hughes

@Maymuna Kabir Hi. Predators, like the Orca, will chase down the weakest member of the family. In this case, it would be the deformed dolphin. :>)

Terry Fillow
Terry Fillow

@Maymuna Kabir Killer whales hunt in packs & would more than likely be targeting the juvenile sperm whales.  Why the dolphin would help is beyond me. 

Vanessa Vigil
Vanessa Vigil

The never ending hunger for power united with being selfish creatures; makes us humans the most vile, aggressive and intolerant species on the planet.   Japan is still hunting whales because they don't want to alter their economy, they are traditionalist in their core, and they don't care for living things if they are not profitable; but that goes to any country and human being with so little empathy for the living; and instead of sharing and understanding they use the comfort and power of the modern world to destroy anything that gets in the way including each other.

Rose Campbell
Rose Campbell

@Caroline Johnson   You tell us to do something for the dolphins but what?  Help me please.  What can we do?  Who do we right  to with our objection and outrage?  It sickens me to think of we arrogant humans are doing to dolphins and elephants, both intelligent species>  Can't people imagine it would be similar to another species slaughtering a group of humans?  Just because WE don't  speak their language does NOT give us the right to write them off as dumb fish and massacre them. Why does Japan still do this?  It's the 21st century not the 15th.  We have so much more knowledge now about the other species we share this planet with you would think we would have developed more respect for others.  No.  Humans are far too greedy, arrogant and selfish.  I'm embarrassed to admit the ones doing the slaughtering are my own kind.  How can we let it continue?

Lorraine Clute
Lorraine Clute

@John M.  Given the observation of play behavior and signs of affection; it doesn't seem likely that the whales are holding the dolphin hostage. As far as I know, I think it's just humans engage in kidnapping. Feel free to correct me if I'm wrong.

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