Chris Mead, of the British Trust for Ornithology, called for the extermination of house crows living wild and breeding in Holland, before there is a population explosion with serious environmental consequences.
"There has been widespread publicity about the damage to wildlife caused by mink escaping from fur farms - well, house crows would be a flying equivalent," Mr Mead said. "They would also be a major pest as far as people are concerned."
He warned that their spread could devastate indigenouswildlife, which has no evolved means of coping with such a predatory alien invader.
In scenes reminiscent of Hitchcock's film The Birds, house crows have been known to mount attacks on people, pets and livestock in the Indian subcontinent, their original territory.
After a report about successful nesting in Holland, Mr Mead put out an Internet message stating: "This species would be an appalling addition to the European list and cause untold damage if it were to increase. Man has been responsible for its appearance - let us hope Man will immediately be responsible for its destruction.
"These birds coexist with Man more successfully than any other species. They scavenge everything and will kill pets, domestic animals and local wild birds. In some areas where they have appeared, virtually all local birds have disappeared. Seriously, shoot them now and save European birds."
Mr Mead's statement is particularly significant as he vigorously defends magpies - relatives of house crows - against calls for their numbers to be reduced due to their feeding on the eggs and young of other birds.
He explained: "Magpies have evolved alongside other species which figure in their diet - they coexist in the same ecosystem. Research has shown no evidence of magpies having any significant effect on other species."
House crows, black with grey necks, are smaller than carrion crows, which are native in Europe, but have comparatively bigger bills, which they use for killing prey. They spread from India to Europe, the Middle East and East Africa by "hitching" rides on ships.Reuse content