Cane toads may be putting the iconic king brown snake on the endangered list in the Northern Territory. In the past, the Environment Department describe the highly venomous species as being common in the rural areas of Darwin and Alice Springs. Dane Trembath, a research associate with the Northern Territory Museum, says king brown numbers have fallen enough for him to nominate the species as vulnerable. He says the king brown population in the Top End may have dropped by more than 90 per cent. "They still are present but they are very, very rare right now," Mr Trembath said. He says the numbers of king browns in the north have plummeted since cane toads arrived in the Territory from Queensland several years ago. An Environment Department spokeswoman says a list of proposed endangered species will be released for public consultation in about a month. Meanwhile, people in Darwin and Palmerston are being urged to gear up for a week of concerted cane toad catching. Environmental group Frogwatch has designated the second week of June as the time to clear out toads that have found a home in suburbia during the wet season. Frogwatch coordinator Graeme Sawyer says the small toads are especially deadly because they are bite-sized for goannas and lizards. "They are also active in the daytime when those animals are foraging," he said. "[Lizards like] frill necks will see these interesting morsels walking around on the ground and come down out of the trees and eat them and die."