Wildlife biologists at Murdoch and Curtin universities have joined forces to study how animals respond to human presence and how that response determines their success living in urban habitats.
Associate Professor Trish Fleming from Murdoch University and Dr Bill Bateman from Curtin University studied the behaviour of eastern grey squirrels in the lower side east side of Manhattan, New York.
“Eastern grey squirrels are extremely successful urban adapters and live in high densities in urban parks where they face reduced risk from predators and are used to humans,” Professor Fleming said.”
“The squirrels have become so comfortable with humans that they show minimal avoidance behaviour of people.
“Animals living in urban areas need to be sensitive to the threat of human presence, but living without fear is a key behavioural trait of urban adaptors.
“The New York squirrels have learnt to ignore non-threatening stimuli, therefore conserving their energy and being able to take advantage of additional resources, such as food sources provided by humans.”
The research found that when humans behave in predictable manners, such as keeping to the footpaths, squirrels appear to pay little attention to the pedestrians. But when people did not stay on footpaths, the squirrels sensed danger and responded accordingly.
“When we remained on the footpath, only 22 per cent of the squirrels moved away compared to 63 per cent that moved away when we stepped off the footpath, even though the distance between us and the squirrel was fixed,” Professor Fleming said.
“When we looked at the squirrels those figures went up. When we remained on the footpath but looked at the squirrels, 40 per cent moved away. If we came off the footpath and looked at them, this shot up to 90 per cent of squirrels moving away.”
The research shows that squirrels are sensitive to cues that inform them about levels of risk and this is an essential ingredient if an animal is to successfully adapt to urban environments.
The researchers said with more urban areas developing, animals would need to adapt to survive and so it was important to know what ensured their success in urban environments.