Do Cape ground squirrels (Xerus inauris) discriminate between olfactory cues in the faeces of predators versus non-predators?

Abstract

One way to avoid potential predators is to be sensitive to odour cues, particularly those in faeces and urine, left by predators. This sensitivity has been demonstrated in many solitary, nocturnal, small mammals which may fall victim to ambush predators.We tested the response of Cape ground squirrels, a diurnal, group-living small mammal, to the presence of predator (black-backed jackal) faeces and non-predator (black wildebeest) dung in baited traps, and also predator faeces and non-predator dung outside their burrows. The squirrels showed a significantly higher avoidance of traps scented with predator faeces than both control and non-predator dung-scented traps. They also took significantly longer to emerge from burrows that had predator faeces outside compared with control burrows and burrows with non-predator dung outside and showed a trend for higher vigilance once they emerged from burrows with predator faeces outside. We argue that as diurnal group-living reduces a reliance on olfactory cues, this species is more likely to rely on visual cues and the vigilance of other individuals than nocturnal solitary species that have been the focus of most studies up till now. As a result, squirrels very quickly return to normal behaviour after exposure to a predator cue. Level of sociality is likely to influence responses to olfactory cues of predators and should be the focus of further studies.