"The dolphins use the strait as a natural trap for catching prey fish, just as people do, " she said.
But they will have to watch out that they are not just fattening themselves up to become prey to still bigger fish.
Some have speculated that overfishing, pollution or rising ocean temperatures may have depleted the kinds of fish that prey on Nomura's jellyfish in the polyp stage.
Unlike human fishing techniques, which tend not to discriminate between sick and healthy specimens, sharks are selective: they target weakened prey, thereby keeping fish populations healthy and strengthening the gene pool.
The shrimps use cavitation to stun their prey - small crabs, fish and worms - or to communicate with other shrimps.
Any prey lurking below, typically a small fish called Mueller's pearlside, will not see the shark coming.
Since their return, the fish-eating birds of prey have generated a lot of interest, and volunteers and the Forestry Commission are now providing daily updates via a blog.
BBC: Ospreys back in Kielder, Northumberland for fourth year
The Maryland researchers concluded that while many fish launch out of the water into the air to capture prey, migrate, or avoid predators, the guppies have a different evolutionary motive: to reach all the available habitat in Trinidad's mountain streams.
If predators are able to operate only in the same number of dimensions as their prey as is the case for lions and zebra, or barracuda and schooling fish then individuals at the centre of a group really should be safer than those at the edges.
Once found mainly in the north east Atlantic, in recent years the fish have tended to head north west towards Iceland and the Faroe Isles following their prey of squid and crustaceans.
应用推荐