Responses of four Critical Weight Range (CWR) marsupials to the odours of native and introduced predators

Abstract

In Australia many critical weight range (CWR) species are threatened by predation from the introduced Red Fox Vulpes vulpes. Understanding how these prey species respond to native predators such as the Tiger Quoll Dasyurus maculatus, and comparing their responses to foxes is important in understanding why fox predation is such a problem. Many northern hemisphere mammalian species have developed responses to the odours of the main species which prey upon them. The situation in Australia remains unclear. We looked at the effect of scenting traps with the faeces of the Tiger Quoll and the Red Fox on the capture rates of four species of CWR marsupials, the Long-nosed Bandicoot Perameles nasuta, the Southern Brown Bandicoot Isoodon obesulus, the Northern Brown Bandicoot I. macrourus and the Common Brushtail Possum Trichosurus vulpecula. None of these species responded to fox odour. However despite low capture rates, Northern Brown Bandicoots and Common Brushtail Possums were captured significantly more often in traps scented with Tiger Quoll faeces. This indicates that these species may be responding to predator odours, but not with the traditionally expected avoidance. Reasons for why this may be so are discussed.

Antipredatory Response and Food Intake in Wood Mice (Apodemus sylvaticus) under Simulated Predation Risk by Resident and Novel Carnivorous Predators

“…Thus, the process of decision‐making under predation risk turns problematic when prey faces up to introduced predators (Jones et al. ; Russell & Banks ). Wood mice could be better prepared to recognize predator species living nearby than predator species introduced recently or allopatric.…”

“…In view of these results, it could be that the ability of prey to detect and avoid predators depends in part on the experience, the ecology and the evolutionary history between predator and prey. Thus, the process of decision-making under predation risk turns problematic when prey faces up to introduced predators (Jones et al 2004;Russell & Banks 2005). Wood mice could be better prepared to recognize predator species living nearby than predator species introduced recently or allopatric.…”

“…Wood mice could be better prepared to recognize predator species living nearby than predator species introduced recently or allopatric. Native species may be less able to respond to predation risk when it comes from an introduced or a novel predator due to a discordant historical evolution between both species (Banks 1998(Banks , 1999Blumstein et al 2002;Russell & Banks 2005); however, over time, wood mice could be able to recognize and avoid European pine marten faecal odour as it has been shown in other prey species when new predators were introduced (Russell & Banks 2007).…”

Negotiating multiple cues of predation risk in a landscape of fear: what scares free‐ranging brushtail possums?

“…However, in the wild brushtail possum responses appear variable. Direct cues of predation in the form of predator odours produced weak (Parsons & Blumstein 2010), short term (Kirmani, Banks & McArthur, 2010) or no response (Russell & Banks, 2005;Mella, Cooper & Davies, 2010b) in free-ranging possums. Responses to indirect habitat-related cues also varied: forest type and open/bush microhabitat had a significant effect on foraging behaviour (Pickett et al, 2005), but distance from the safety of trees did not affect foraging (McDonald-Madden et al, 2000).…”

Overcoming prey naiveté: Free‐living marsupials develop recognition and effective behavioral responses to alien predators in Australia

“…Demonstrating naiveté is challenging, as a lack of response to an alien predator cue could either represent a lack of recognition of the predator (level 1 naiveté sensu Banks & Dickman, ) or conversely a sophisticated response where the cost‐benefit ratio of the risk is considered and the animal chooses to ignore the risk to access other resources (Carthey & Banks, ; Parsons et al., ). For example, the apparent naiveté of a small mammal demonstrated by the classic “scat‐at‐trap” technique (e.g., Russell & Banks, ) could indicate a decision that the benefits of the food attractant outweigh the perceived potential predation risk inferred by the scat. It is also difficult to demonstrate a change in prey naiveté or the development of predator recognition, and while past works have suggested this (e.g., Anson & Dickman, ; Carthey & Banks, ), animals without historic exposure to the predators were not tested and initial naiveté was assumed.…”