Sheep are expected to return to a Brighton park after an absence of nearly 100 years.

The environmentally friendly lawnmowers could be reintroduced to Wild Park, in Moulsecoomb, Brighton, this winter to boost the growth of wild plants, which rare insects feed on.

Council bosses are now calling for volunteers to shepherd the new flock.

David Larkin, a Brighton and Hove City Council countryside ranger, said: "We provide a day's free training for volunteers and then we will produce a rota so people can check the sheep are OK.

It's up to the volunteers how often they want to work but it could be as little as 15 minutes once a week."

The 315-acre Moulsecoomb estate, which included Wild Park, was bought by Brighton Council in 1925.

Part of the park was briefly used as a rabbit warren. Before that it had been grazed for centuries by sheep.

Wild Park was a major attraction for Victorians, who visited the area to see unusual butterflies such as the blue adonis and wild flowers.

It was thought the landscape would remain as grassland but as it was left to nature it rapidly became a wilderness of scrub and woodland, losing many species.

Mr Larkin said: "If this grassland disappears we will lose the adonis blue butterfly. Its caterpillars will only eat horseshoe vetch, which only grows in wild sheep pasture.

It's like a rainforest but in miniature, created by sheep grazing over centuries."

Under the scheme, a flock of about 50 sheep from a Sussex Wildlife Trust farm in Southerham, near Lewes, will graze the park's steep hillside for three weeks next winter. If it proves successful, a larger flock will be introduced next year.

The scheme has been run in other places in Brighton and Hove, including Sheepcote Valley, Waterhall and Bevendean Down. Sussex Wildlife Trust has sheep grazing at 13 of its 32 nature reserves.

Trust chief executive Tony Whitbread said: "We are very much in favour of restoring grazing. It will create diversity, which will give more living space for rarer species.

"If you take the point that the South Downs holds a lot of specific and unusual species, which are restricted to the chalk landscape, this is the way to conserve them.

"There will be concerns about the welfare of the sheep and people will have to be sensitive with dogs. But that's not a reason for not doing it.

It's a reason to get it right."

Anyone interested in volunteering as a sheep watcher should call Brighton and Hove Countryside Service on 01273 292140.