Along the shore of South Africa, at least four great white sharks have washed ashore with their livers almost surgically removed. Two were also missing their hearts. The culprit appears not to be human. All indications seem to suggest that orcas have removed the organs from the sharks, causing them to bleed out. One male shark carcass was found on June 24 in a relatively fresh state of decomposition, missing not just its liver, but its stomach and testes as well.
Why are orcas attacking great white sharks, and why are they only taking specific organs? No one has a clear answer.
As noted on the IFLScience blog: As we noted previously, the specificity of the organ harvesting isn’t too unusual – when hunting whales, orca sometimes kill their calves and only eat their tongues. Some organs provide a lot more energy than the rest of the flesh, so perhaps this type of feasting is a form of energy conservation.
Orcas would expend a lot of energy just killing a great white shark in the first place though, so this idea may be invalid.
In any case, their precise removal of these organs from a thrashing great white is as mysterious as it is unprecedented.
A concerned yachtsman showed me pictures of 24 dead guillemots in the Largs Channel. They had been neatly opened up and the internal organs removed. It was quite spooky. I passed them on to some scientific friends who it turned out had seen similar before. The cause was the flock of birds had been chasing a shoal of fish and were trapped in a trawl net where they drowned. The carcasses were discarded by the fishing vessel and opened up by gulls with the efficiency of a surgeon and the wisdom of a chef.
Gulls also take mussels from the local marina piles at low tide, fly up and drop them onto the pontoons which breaks open the shells. Crows have copied them but they take the mussels up to the car-park because there is no chance of them falling off the sides of the pontoon back into the water.