T SINGLETON asked for someone to explain about the cows and their associated "muck" (May 4).

Hob Moor is one of three statutory Local Nature Reserves in York, the designation of which is not given lightly.

Hob Moor was an LNR due to its diverse range of flora and because it is a breeding ground for the red-listed skylark.

Both of these would not be here if it were not for the grazing regime of summer pasture which has been employed on the Moor for centuries.

Certain plants live in association with each other depending upon the underlying soil conditions below and the management of the plants above.

At Hob Moor, centuries of summer grazing has resulted in the type of grassland we have. If the cattle were excluded we would have to mimic the grazing by mowing, probably at some point around the end of May and then again at the end of the season, around September.

If we did that, we would destroy the nests of the skylark and meadow pipit, which is illegal. It would also create a less diverse, uniform habitat of grassland all at the same height, instead of the mosaic of different lengths of vegetation and of flowering plants throughout the season.

In summary, the cows are essential to the management of the reserve and can be credited with making Hob Moor such a special place.

Unfortunately the by-product of their dung is something we will have to live with if we want to enjoy Hob Moor as it has been for centuries.

Stephen Whittaker,

Local nature reserves officer,

City of York Council,

Back Swinegate,

York.

Updated: 09:47 Friday, May 06, 2005