SYDNEY, Oct. 6 (Xinhua) -- Wild deer numbers are jumping in southeast Australia, with many farmers calling on authorities to do more to control what they see as pests threatening livestock and the environment, according to latest local media reports.

They physically eat trees and shrubs so they're browsing for food as well, snapping branches off, running through fences, and actually grazing our pastures, livestock farmer Tom Abbottsmith Youl from Victoria state told local reporters.

"It's not a game. This is serious business. It's affecting our small business here and it's affecting our native bushland," the ABC news channel quoted Youl, who added that he has had to reduce his livestock numbers by 5 percent to accommodate the impact of deer on his land, as saying on Saturday.

Deer, which were introduced into Australia in part for recreational hunting, are still considered game animals that can be hunted under regulations in Australian states such as Victoria, New South Wales and Tasmania but their growing numbers are increasingly fueling calls by farmers to categorize them as pests for better management.

Up to 1 million deer are estimated to be in Victoria alone, with reports of sightings rising across the state.

"We want deer to be transferred from being a game animal to a feral animal or an introduced species, invasive species, and that then allows different methods of control," Victorian Farmers Federation livestock president Leonard Vallance told ABC.