Ecologist taking on MoD to protect skylarks says he has faced threats and assault

Campaigners say rare grassland on former firing range in Essex was mowed, killing the birds and their chicks that nest on the ground

The song of the skylark has filled poets' hearts for centuries, from Shelley's blithe spirit" to Wordsworth's ethereal minstrel". But there is little that is poetic about a row over the birds that has blown up in Colchester.

Campaigners seeking to save Middlewick Ranges, a former Ministry of Defence firing range in Essex, are furious that some of the 76 hectares of rare grassland were mowed last month, an act that they believe has killed skylarks and their chicks, which nest on the ground.