Simulating a ‘landscape of fear’: Eastern grey squirrels (Sciurus carolinensis) reduce proportional feeding duration under exposure to native and invasive predator cues

Abstract

Abstract a) The Landscape of Fear (LOF) concept proposes that a prey individual’s perceived risk of predation can affect their distribution and activity. Prey may perceive the risk of predation following the detection of predator cues, such as auditory, visual, and chemical signals; this has been demonstrated in numerous studies. b) There is limited understanding on the extent of the role that chemical predator cues play under the LOF concept. Within this study, a range of olfactory cues, including those of native and invasive predators, were applied to artificial feeders used by eastern grey squirrels (Sciurus carolinensis) in a single urban site in the United Kingdom. Motion- activated cameras recorded squirrel feeding and vigilance behaviours. The durations of such behaviours were collated and analysed to determine whether the simulated presence of predators using affected squirrel foraging. c) Domestic cat (Felis catus) odours significantly reduced proportional squirrel feeding duration at feeders, compared to passive and active controls (distilled water and rabbit (Oryctolagus cuniculus domesticus) urine, respectively). Pine marten (Martes martes) faeces significantly reduced proportional squirrel feeding duration compared to feeding under passive control applications.(Werner and Anholt 1993; Maynard-Smith et al. 2003; Scott-Phillips 2008) d) Our results confirm previous knowledge on the LOF theory; olfactory cues of a predator disrupt prey foraging. These observations provide an insight into how predator scents can affect the distribution, feeding, and anti-predation behaviours of prey. e) Our results are discussed in the context of the following areas: the application of predator scents as a deterrent of domestic cats in an urban environment; the wider effects of pine marten reintroductions on introduced eastern grey squirrel populations; the evolutionary significance of predator chemical cues.