The number of waders (shorebirds) in Sweden is falling rapidly, so scientists at the University of Gothenburg have been testing a number of non-lethal methods to protect species such as the Northern lapwing and redshank from predators for the past few years in the coastal meadows of Halland in southwestern Sweden.

Their attempts involve placing protective cages over the nests and spreading decoy eggs injected with a drug to induce vomiting.

"Both lapwing and redshank hatched more eggs when their nests were inside the cages," reports researcher Daniel Isaksson from the Department of Zoology. Another method involves artificial nests containing ordinary chicken eggs painted to resemble waders eggs and injected with an emetic - a drug that induces vomiting - which researchers hope will "teach" the predators that waders' eggs are inedible.

"We found that predation of the real waders' eggs immediately decreased during the first three weeks in areas with the decoy eggs, which suggests that the method had an effect," said Isaksson.