Extinct or endangered birds could be revived by hens created to produce eggs of different species, scientists have said.
Researchers at the organisation which produced Dolly the sheep, the first cloned animal, said a genetically modified chicken has already been fathered by a duck.
The technique involves extracting the cells responsible for producing sperm and eggs from a bird embryo then injecting them into the reproductive organs of a chicken embryo.
When the chicken matures, it will produce the sperm of whatever species those cells came from.
Researchers want to create hens capable of producing different bird species including poultry, songbirds and even eagles.
Mike McGrew from the National Avian Research Facility said: "We could propagate endangered species or potentially bring back an extinct one if we had the right genetic material."
