Wood pigeons are flocking from the countryside to towns and cities because of changes in farming, a bird research charity has said.
Increased garden bird feeding by people is also fuelling the migration, said the British Trust for Ornithology.
A survey by 16,500 householders found wood pigeons in 46% of London gardens, compared to just 27% for the more familiar feral pigeon.
The BTO said it was "amazing" how quickly the wood pigeon had adapted.
The trust's Garden Birdwatch survey encourages the public to report sightings on their own doorstep.
It says that a decade ago the wood pigeon did not appear in the list, but now it is the fourth most common species identified.
As well as outnumbering London's traditional pigeons, the wood pigeon is also in the ascendancy in Manchester where it was reported in 61% of gardens.
In contrast, the town pigeon was sighted in just 34%.
The BTO put the shift down to changes in farming practices, such as sowing cereals in autumn which leaves the birds without areas of crop stubble to feed on over the winter.
The increased popularity of bird tables and feeders in urban gardens has also lured birds to the city.
Paul Stancliffe, from the BTO, said: "It is amazing how quickly this bird of farm and woodland has become a familiar sight on the streets and pavements of some of our busiest towns and cities."
The wood pigeon is the largest of the six pigeon and dove species which breed in Britain.
The country is home to an estimated three million pairs during the summer months.