UPLAND birds may be as vulnerable to climate change as song birds, according to a new study.

The golden plover, found on the moors and peat bogs of the North Pennines and Teesdale, is breeding significantly earlier than 20 years ago.

But scientists say the chicks' main prey - daddy long legs or craneflies - are not adapting at the same rate.

They fear the golden plover and species such as the greenshank and red grouse could be threatened by a shortage of food.

The warning has been issued by the Royal Society for the Protection of Birds and scientists from Newcastle and Manchester universities.

Dr James Pearce-Higgins, research biologist at the RSPB, said: "The earliest hatching plover chicks, which normally have the best chance of survival, could in future struggle to find food, reducing their overall breeding success and threatening the population size."

The species in the UK has been protected by EU law since 1979, because of its importance.

The study, published in the journal Oecologia, warns that if climate change predictions prove accurate, golden plovers will be nesting three weeks earlier by 2100.

Researchers studied 25-years' worth of data, finding that the first plover chicks now hatched on average nine days earlier than the mid-1980s, because of recent, warmer springs.

While craneflies would adapt to some extent, they were unlikely to be present in sufficient numbers to sustain the earliest golden plover chicks. Craneflies were abundant on moorland for just two or three weeks.

The upland habitats are internationally important - almost 75pc of the world's moorland and ten- to 15pc of peat bogs are found in the UK.

"Action to limit climate change is vital to reduce its destructive impact and ensure these birds' survival," said Dr Pearce-Higgins.

Upland and moorland birds are thought to be most susceptible to climate change because they inhabit cooler, higher areas.

Temperature rises force them higher, but in the UK there is only so far north, or up hill, they can go.

Climate predictions are worse for more northern areas such as the Arctic, which is also inhabited by golden plover, where temperatures are predicted to rise by six degrees celsius.

The RSPB will now identify the most vulnerable upland species in a project part-funded by Scottish Natural Heritage.

Its scientists will assess data for a wide range of rare and declining species, such as dotterel, curlew and ring ouzel.

"Our findings will help us assess whether habitat management, such as altering grazing levels or blocking drains, can counter the consequences of climate change for birds, or if the effects on birds will be too great," said Dr Pearce-Higgins.

"Golden plovers, for example, are right on the southerly edge of their global range in the UK, and therefore most likely to decline here. That makes the UK a good place to study them."