A group working to control cane toad numbers in the Northern Territory says more than 90 million toads are throwing the food chain into disarray.
FrogWatch NT says more than 92 million cane toads across the Territory are eating 18 billion food items every night.
The group says the competition for food is one of the reasons so many native species are in decline.
Research conducted by the group last year found an average of 209 toads per square kilometre in Territory savanna areas.
"FrogWatch finished in December last year some research in 110 square kilometres of savanna woodland," said FrogWatch coordinator and Darwin Lord Mayor, Graeme Sawyer.
"We spent a fair bit of time and effort trying to eradicate every single cane toad in that area and we got just over 23,000 cane toads."
He says the group then extrapolated that data across other savanna areas in the Territory to come up with the figure of 92 million toads.
"We realise there's huge risks in that sort of mathematics but we used some fairly conservative estimates on numbers so the reality is probably a higher number of cane toads than that."
Mr Sawyer says toads are locking up nutrients, seriously disrupting the food supply for native animals.
He says wildlife authorities have not done anything to control cane toad numbers in national parks, which explains recent data showing a decline in the number of native animals.
The group has called on authorities and researchers to spend less time seeking funding and focus more attention on tackling the invasive pest.