Monitoring indicates rapid and severe decline of native small mammals in Kakadu National Park, northern Australia

A rapid and severe decline of native small mammals has been documented in Kakadu National Park, northern Australia, challenging the assumption that its mammal fauna remained intact. Over a 13-year study (1996–2009), species richness and total abundance decreased by 54% and 71%, respectively, with 10 out of 25 recorded species showing significant declines. The most pronounced losses were observed in northern quoll, fawn antechinus, northern brown bandicoot, common brushtail possum, and pale field-rat. The study employed consistent sampling across plots representing environmental variation and fire regimes, using regression analysis and Wilcoxon matched-pairs tests to assess change. Declines correlated with increased fire frequency, suggesting that too frequent fires, predation by feral cats, and cane toad invasion may be contributing factors. These findings indicate a major conservation crisis in northern Australia, comparable to the losses seen elsewhere on the continent.

Woinarski, J. C. Z., Armstrong, M., Brennan, K., Fisher, A., Griffiths, A. D., Hill, B., Milne, D. J., Palmer, C., Ward, S., Watson, M., Winderlich, S., & Young, S. (2010). Monitoring indicates rapid and severe decline of native small mammals in Kakadu National Park, northern Australia. Wildlife Research, 37(2), 116–126. https://doi.org/10.1071/wr09125