Jonathon Howard, NPA Executive Committee
Mammals that prey on other animals leave their scent in the environment. These scents can alert prey species to the presence of predators and may lead to a fear-like avoidance response by their prey. However, if the predator is an introduced predator such as a cat or fox, then the prey may not be able to associate the scent of an introduced predator.
Researchers at Charles Sturt University have investigated the ability of Australian birds to recognise native and exotic predators. They used scented and unscented bird baths, to test whether seven species of honeyeaters respond to the odours of a native predator (brush-tailed possum), two exotic predators (cat and brown rat), and a native herbivore (koala).
They found honeyeaters visited baths with possum scent less often than control baths and they also spent less time at these scented baths. Honeyeaters were also less likely to drink or wash in possum-scented baths than in control baths. Honeyeaters also avoided rat- and cat-scented bird baths, but the aversion to these baths was less strong than to possum-scented baths. These results show that some birds, like mammals and reptiles, use smell to assess predation risk, but how strongly honeyeaters responded to predator scents varied depending on how long predator-prey dynamic has existed.
Given introductions of exotic mammalian predators to islands can cause severe population declines and extinctions of native species, it is concluded that coexistence with exotic predators for over 100–200 years is necessary for some Australian birds to recognise novel predators by scent.
You can read the article here: Can Australian honeyeaters recognise the odours of native and exotic predators? | Behavioral Ecology and Sociobiology | Springer Nature Link