New York squirrels are nuts about city life

Media release

Curtin University-led research has shown squirrels have adapted to New York City’s human behaviour, allowing them to thrive just as well, if not better, than their fellow squirrels in the woods.

A North Eastern Squirrel

Dr Bill Bateman, Senior Lecturer at Curtin’s Department of Environment & Agriculture, led the study that proved eastern grey squirrels were able to modify their behaviour in urban environments and prevent unnecessary responses when humans acted in a predictable manner, such as staying on the footpath.

“As we rapidly increase the spread of urbanisation around the world, urban areas may end up being important places for some wildlife, so it would be good to know what they like about those areas, what allows them to do well and whether humans want them to be there,” Dr Bateman said.

“If we do want them there, we need to know how we can help their continued success, and perhaps encourage other animals to share our urban spaces.

“After watching the clear-cut behaviour of squirrels many times in New York, I decided to take these observations further and determine to what extent squirrels modify their behaviour when approached by humans.”

Together with Murdoch University’s Associate Professor Trish Fleming the research team measured alert distance, flight initiation distance, and distance fled to see if they could discriminate between pedestrians who look directly at them and those that did not, as well as how they reacted when pedestrians left the footpath.

According to the research, only five per cent of squirrels showed signs of being alerted if the human remained on the footpath and did not look at them, while 90 per cent of squirrels moved away, with longer flight distance, when approached by a pedestrian that moved off the footpaths and looked at them.

“This research shows squirrels are able to modulate their behaviour when humans behave in a predictable manner, reducing unnecessary responses and improving their ability to persist in an urban environment,” Dr Bateman said.

“Generally, it seems animals do well in urbanised areas if they can eat a wide range of things and are able to move from one green space to another. Being nocturnal also helps to avoid humans, as well as being behaviourally able to deal with humans and their disturbance, as squirrels do.

“For a squirrel, the city provides a habitat with fewer predators than in the woods, and food tends to be available all year around. Traffic, however, remains the biggest killer for all urban wildlife.”

Dr Bateman said in Australia there were many species of birds, mammals and reptiles that live moderately well in urban areas, and had plans to explore their behavioural responses to various human activities in the future.

The research, Does human pedestrian behaviour influence risk assessment in a successful mammal urban adapter?, published in the Journal of Zoology, is available at http://onlinelibrary.wiley.com/doi/10.1111/jzo.12156/abstract.