The effect of food weight on transportation by the Japanese squirrel (Sciurus lis)

Abstract

We conducted an experimental study on the relationship between transportation behavior and food size (or weight) for Japanese squirrel (Sciurus lis) in a suburban forest of Nagoya city, Japan. We placed artificial food samples of two or three sizes on a feeding tray, randomly selected from eight different sizes of 1–15 g. Larger food was more likely to be transported from the food source and into tree canopies than smaller food. This could be because larger food caused a higher risk of predation (resulting from longer handling time) and of cache-robbery by mice and other squirrels (because of higher energy contents). Compared with small food, large food was also dispersed farther away to reduce density-dependent cache robbery. However, the heights transported by squirrels did not differ with food size, indicating that height was not important in avoiding predation during feeding or cache robbery when food was hoarded.