Endangered farmland birds in the UK like the tree sparrow are to be offered a lifeline this winter following research into their feeding habits.

Farmers are to be encouraged to plant seed-bearing crops shown to provide essential food for the birds.

Several species of farmland birds such as the linnet, yellowhammer and tree sparrow have seen a severe decline in numbers over the past 25 years.

One reason is thought to be the shortage of seeds for them to eat over the winter, due to the earlier sowing of crops by farmers, according to a three-year government-funded research project published on Monday.

Farmers' grants

The research, carried out by The Game Conservancy Trust and the Allerton Research and Educational Trust, was based at the GCT's Allerton Project in Leicestershire.

It indicated that many different birds feed on plants grown to encourage pheasants reared for shooting. It found that a wide variety of farmland birds fed on seeds from just two crops: the health-food plant quinoa and kale used in livestock fodder.

Dr Nigel Boatman, from the Allerton Project, said: "This work shows the value of game crops in feeding farmland birds through the winter. It provides guidelines for developing the same principles in the form of a new 'wildlife seed mixture' prescription which will hopefully soon be available through the Countryside Stewardship scheme."

From the New Year, farmers will be offered grants to plant these and other seed-bearing crops in an effort to reverse the decline of endangered bird species.

The number of tree sparrows alone has dropped by 90% since 1970.