Seasonal variation of flight initiation distance in Eurasian red squirrels in urban versus rural habitat
Urbanization has caused significant behavioural modifications in wild animals. Change in anti predator behaviour is the most widespread example across different taxa in urban areas, which is probably due to a decrease in predation pressure and habituation towards humans. Seasonality or phenology has also been modified by urbanization since some resources in urban environments are highly controlled, for example, artificial feeding. Under natural conditions, anti predator responses vary with seasonal variability in environmental and individual conditions. However, resource stability possibly reduces the seasonality of anti predator behaviours in urban animals. Here, we compare the seasonal difference of flight initiation distance (FID) a measurement of anti predator response, in Eurasian red squirrels Sciurus vulgaris between urban and rural areas in the Tokachi region, Hokkaido, Japan. Rural squirrels possessed FIDs two to three times longer than those of urban squirrels. We also found squirrels in rural areas lowered FID in autumn, but no seasonal difference was observed in urban squirrels. Our results suggest that continuous supplementary feeding may have buffered the seasonality in anti predator response. In addition, strong habituation to humans may allow urban red squirrels to correctly assess human activity as benign rather than reacting unnecessarily.