Daryl wrote:Predators tend to be the worst ecological vandals.
Humans obviously, but our country has had its share. Cats, foxes, dogs, pigs, rats, cane toads are all big problems. Then yes, grazing animals are also a problem, with feral camels, horses, donkeys, rabbits, hares, and more causing big problems. At one stage a big proportion of our arable land was overrun by prickly pear cactus, which was only beaten by a risky biological agent (cactoblastus grub).
Those in long established northern hemisphere countries can't comprehend just how dangerous introduced species can be.
Trust me, we have issues too. Recent Chinese pests introduced to N. America have caused havoc on ecosystems here. The Zebra muscle, introduced by the purging of Ocean going Ship's ballast tanks, have completely changed the ecology of the Great Lakes. They killed off several species, and now are clearing the water of sediments - that sounds good, right? However, it allows sunlight to penetrate further into the water and fosters algae growth. The local Blue algae, usually kept in check and growing in small amounts, now form massive blooms in the summer, releasing dioxin toxins into the water making bathing or drinking the water dangerous.
The Emerald Ash borer has killed off most of the Ash trees in the effected areas N. America (The Chinese Ashes can surrive them). Dutch Elm disease did the same for most N. American Elms in the 70s and 80s. Chinese Carp are literally jumping out of the water in the Mississippi river and Chicago river, after killing off the local carp and breeding out of control after some escaped captivity from experimental fish farms in the 60s and 70s.
The list goes on and on. Australia isn't the only place such impacted.