SECURITY systems in towns and cities has led to some people feeling that Big Brother is watching them more and more.

But cows in remote countryside have so far avoided having their every move recorded by a surveillance system - until now.

Three of a herd of 50 blue grey and beef shorthorns have been fitted with electronic collars so they can be tracked by satellite to help conserve the Yorkshire Dales National Park.

The collars contain a global positioning system (GPS) receiver to give an instant fix on the animals' position and a data logger to record information for a computer.

The equipment can even tell if a cow has its head down grazing, is standing still, or moving.

The experiment on the Ingleborough nature reserve, in North Yorkshire, will help to improve wildlife management on farm land.

The pilot scheme is the latest phase of the Limestone Country project, launched in 2002 to preserve rare plants by returning to mixed livestock grazing using hardy, native cattle breeds.

Reserve manager Paul Evans said collars were fitted to three cows which graze almost 200 hectares of upland.

"The cattle are free to roam over pretty large areas so, at any one particular time we don't always know exactly where they are or what they are doing," he said.

"This is one of the first projects of its kind to use GPS collars on livestock. Normally they are put on wild animals like polar bears and tigers to track their movements.

"The idea is to find out where they go and at what times of the day and the year. We can then analyse the vegetation and terrain in those areas, for example grassland, peat bog or scrub.

"That will tell us what they prefer to eat during the different seasons of the year and this will help us to asses their impact on the local ecology."

Louise Williams, the national park authority's Limestone Country project officer, said: "The results will be vital in helping us to provide detailed information about animal behaviour and grazing patterns, both of which are important for the future of livestock farming in these upland areas."