Seasonal Responses to Predator Faecal Odours in Australian Native Rodents Vary Between Species

Abstract

Small mammals are subject to predation from mammalian, avian and reptilian predators. There is an obvious advantage for prey species to detect the presence of predators in their environment, enabling them to make decisions about movement and foraging behavior based on perceived risk of predation. One technique commonly exploited to assess this risk is to use the odours of the faeces and/or urine of their predators to determine presence/absence and the length of time since a predator passed through an area. I examined the effect of faecal odours from marsupial and eutherian predators, and a native reptilian predator, on the behavior of three endemic Australian rodent species (the Fawn-footed Melomys Melomys cervinipes, the Bush Rat Rattus fuscipes and the Giant White-tailed Rat Uromys caudimaculatus) in rainforest remnants on the Atherton Tableland, North Queensland, Australia. Infrared camera traps were used to assess visit rates of rodents to odour stations containing faecal and control odours. Rodents avoided odour stations containing predator faeces, but did not avoid herbivore or control odours. The responses of the three prey species differed: in the late wet season U. caudimaculatus avoided predator odours, while R. fuscipes and M. cervinipes did not. In contrast, in the late dry season all three species avoided odour stations containing predator odours. I speculate that these differential responses may result from variations in life history traits between the species.