A small dasyurid predator (Sminthopsis virginiae) rapidly learns to avoid a toxic invader

作者：Webb Jonathan K^*; Pearson David; Shine Richard

来源：Wildlife Research, 2011, 38(8): 726-731.

DOI：10.1071/WR10206

Context. Invasive species are a leading cause of extinctions, yet predicting their ecological impacts poses a formidable challenge for conservation biologists. When native predators are naive to invaders, they may lack appropriate behaviours to deal with the invader. In northern Australia, the invasion of the highly toxic cane toad (Rhinella marina) has caused serious population declines of reptilian and mammalian predators that are ill equipped to deal with toad toxins. Cane toads recently invaded the Kimberley region of Western Australia, where they potentially threaten several species of small dasyurid predators.
Aims. We investigated whether red-cheeked dunnarts (Sminthopsis virginiae) attack cane toads, and if so, whether individuals subsequently learn to avoid toads as prey.
Methods. We quantified feeding and learning behaviours in toad-naive red-cheeked dunnarts from the north Kimberley in Western Australia.
Key results. All toad-naive dunnarts attacked toads during their first encounter. Most dunnarts bit the toad on the snout, killed it by biting the cranium, and consumed the toad snout-first, thereby initially avoiding the toad's parotoid glands. Most dunnarts partially consumed toads before discarding them, and only one animal showed visible signs of toad poisoning. All dunnarts rapidly learnt to avoid toads as prey after one or two encounters. Predators rejected toads as prey for the duration of the study (22 days), suggesting long-term retention of the knowledge that toads are noxious.
Conclusions. Our results show that red-cheeked dunnarts rapidly learn to avoid cane toads as prey.
Implications. Our study was limited by small sample sizes, but our results suggest that small dasyurids can adapt to the cane toad invasion via taste aversion learning.

• 出版日期2011