Late at night the howling of wolves still echoes through the dark shadows of Bialowieza forest, where the last European bison roam and more elks than humans tend to tread. For centuries only the odd Polish king, Russian tsar or Lithuanian duke out hunting disturbed this vast forest, a last fragment of the primeval woodlands which once covered much of Europe. But since the Polish government eased the restrictions on logging the piercing sound of chainsaws has increasingly disturbed the peace. Forestry companies, supported by the government, have felled hundreds of ancient trees. The logging is the most intense for 50 years. Crudely hacked clearings scar the outer ring of the 2,600 sq km (1,000 sq miles) of forest where the loggers have carved tracks for their trailers between Norwegian spruce and lime trees.