Skip to comments.Killer Dolphins Baffle Marine Experts
Posted on 01/26/2008 11:58:30 AM PST by DogByte6RER
Killer dolphins baffle marine experts
By Nigel Blundell
Last Updated: 12:01pm GMT 25/01/2008
It's hard to visualise but the intelligent and ever-friendly dolphin can also be a determined killer.
New evidence has been compiled by marine scientists that prove the normally placid dolphin is capable of brutal attacks both on innocent fellow marine mammals and, more disturbingly, on its own kind.
Film taken of gangs of dolphins repeatedly ramming baby porpoises, tossing them in the air and pursuing them to the death has solved a long-term mystery of what causes the death of so many of these harmless mammals - but has left animal experts baffled as to the motive.
Another mystery is that the animal 'murders' have only been reported in two parts of the world - along Scotland's East Coast and in America off the beaches of Virginia, where even more alarmingly, the victims were scores of the dolphins' own young.
The first clues to solving the riddle came in 1997 when, by coincidence, marine biologists in Virginia were finding young, dead dolphins with horrific internal injuries at the same time as young porpoises were washing up on Scotland's north-east coast with identical causes of death. The body count was growing in both locations.
The two groups of biologists pooled information and, at first, it was believed the mammals had died through 'blast trauma'. In American cases, this was supposedly from exercises by the US Navy, and in Scotland from air guns used by oil rig technicians to detect undersea caverns.
This theory was dismissed after further examination of the mammals' bodies revealed the injuries - broken ribs, imploding lungs, damaged livers and massive internal bleeding - could only have come from prolonged, focused attacks.
When tell-tale teeth-marks were identified, the dolphin - the mammal classified as one of the world's most intelligent, sensitive and sociable creatures - became the official suspect.
Confirmation of the murders came by way of two shocking films shot by holidaymakers.
The first was initially believed to show a dolphin fishing for salmon - until closer examination revealed a relentless attack on a porpoise, its body spinning round with such force that its back was broken and its soft tissue shattered.
Marine experts now believe that these displays of attacks on non-rival, non-predatory, peace-loving porpoises and, more shockingly, of dolphin infanticide, may have always taken place.
It is only now, with dolphins' more human-friendly behaviour taking them closer to tourist boats and beaches, that the violence is being witnessed first hand. Until the shocking realisation, dolphin-watchers in America had believed they were watching the mammals at play with their young.
Four years ago, members of Scots charity the Cetacean Research and Rescue Unit discovered a lifeless porpoise near the harbour at Whitehills, near Banff.
The team described the mammals' injuries as "perhaps the worst example of inter-specific aggression any of us had ever seen. This young female had literally had the life beaten out of her."
Inspection showed multiple lacerations and puncture wounds all over the body which could not have been caused by any other attacker than a bottle-nosed dolphin.
Two of these fatal attacks by dolphins feature in the documentary The Dolphin Murders, being shown in the channel Five series Nature Shock on Tuesday, January 29.
Watching the films, Aberdeen marina biologist Dr Ben Wilson explains yet another shocking phenomenon - that the dolphins use their incredible ultra sound abilties to home in on the vital organs of their victims that will cause most damage.
"The blows are carefully targeted," says Dr Wilson, who is a member of the Scottish Association for Marine Science. "And the attacks are sustained, sometimes up to 30 minutes.
"The film was a key piece of evidence. It crystalised our suspicions. We realised the dolphins' victim was trying to escape from being attacked with such force that any one single blow could kill it.
"It was, Oh my God!, the animals I've been studying for the last 10 years are killing these porpoises."
Theories abound on the reason behind the mammal murders. These have included territorial clashes and feuds over food resources. But food is not in short supply and the victims are not just chased away but pursued to the death.
Another belief is that dolphin attacks on their young may be down to mating instincts, because when her calf dies the female dolphin is ready for mating again. But the experts are still not positive that it is only males who do the attacking.
And, incredibly, they can only guess that the attacks by bottle-nosed dolphins on Scotland's harbour porpoises is some kind of bizarre 'target practice.'
For the one common link between the attacks here and America is that the victims are of a similar size and weight.
Perhaps the dolphins' instincts has them practising the same skills required to separate a porpoise from its school, pursue it and kill it as are needed for attacks on its own kind.
Nearly half of the harbour porpoises' bodies examined have died as a result of the dolphin attacks.
Perhaps some answers will be found as Dr Wilson - who has written several research papers on dolphins - and his team continue their Bottlenose Dolphin Project throughout the Scottish waters this winter. The field work is expected to end in the summer.
But as the experts of the Cetacean Research and Rescue Unit are forced to declare: "These killings represent yet another example of the hard brutality and evolutionary pressures of the marine world."
It's a good thing they taste like tuna! : )
I wonder if they ever found those attack dolphins that escape because of Katrina, ergo hoc, it’s Bush’s fault!
I knew giving them lasers wasn’t a good idea.
Maybe hard to imagine in your PC, gay friendly, reality denying universe.
kill the young of another male dolphin, the female goes back into heat and you can pass on your genetic material. sounds simple enough.
Come on now, we all know it is caused by global warming. Global warming causes the oceans to heat up, which in turn causes the dolphins to get uncomfortable and go crazy.
They are so human-like aren’t they?
Actually they were created by Halliburton, for Blackwater, to blow up oil rigs to drive the price of oil up, so that we could invade Iran for the oil.
There is a lot of talk about all the estrogen from birth control pills passing in urine and into the environment is causing havoc in wildlife.
In other words, dolphins are more like people than we thought. All they need is a few tattoos or nose rings.
Yes. Don’t Lions do the same?
The ones that beach themselves just can’t take the violence anymore and do it as a protest.
Shoot, I thought it was about the football team and Parcells(tuna). Oh well.
read any of the step-dad/mommies new boyfriend threads around here? crass, i know, but true to a point.
Except that, as stated in the article, it’s not only males that are doing the killing. Maybe it’s the alpha male’s sister helping out.
Dolphins gone wild. What is this world coming to?
Maybe their doing it out of self-hate over the performace of their namesake football team.
“I wonder if they ever found those attack dolphins that escape because of Katrina, ergo hoc, it’s Bush’s fault!”
The Navy trained a few attack Dolphins, they escaped back to the hood and started a gang.
could be. or there could be something wrong with the pup and the rest do not want the competition for food. there are many possible reasons. reproduction and resources are usually the culprits.