The Comparison Of Hoarding Behavior Of Red Squirrels Between Urban Green Area And Liangshui Nature Reserve

A comparison of the hoarding behavior of red squirrels (Sciurus vulgaris) between urban green area and Liangshui Nature Reserve was made in this paper from March 2009 to February 2010. The contents of this research include:finding the difference of squirrels' activity rhythm, food selection, and hoarding-retrieving behavior between urban green land and Liangshui Nature Reserve. The main research results are as follows:Because urban red squirrels lived in urban green area, a kind of special environment with more human disturbance, the activity rhythm of squirrels, hoarding-retrieving behavior had adaptable changes. In urban green area, squirrels were feed by food of fixed quantity at fixed time. Their activity showed apparently regular pattern throughout the whole year. Squirrels went out of nests about 6:00, and the peak of activity in the morning was during 7:00-8:00, and the peak of activity in the afternoon was during 14:00-15:00. However, temperature had great impacts on the activities of squirrels in Liangshui Nature Reserve, and the activities of squirrels fluctuated intensely in winter.The food of squirrels in urban green area was different from the Nature Reserve. In urban green area, the food type of squirrels was controlled by people, including nuts, fruits, vegetables, even some cooked food and bread. Under the condition of fixed-quantity feeding, squirrels hoarded the remained food after forging, and also hoarded the rest food even if the ground surface was covered by snow, which showed the preference of excessive hoarding. Averagely each squirrel hoarded about 12150±3078 caches in a year. When food supply was insufficient, squirrels in urban green area retrieved the cache. The retrieving behavior of squirrels had no connection with season, but with the abundance of food supply or not. The squirrels in the Nature Reserve mainly selected some nuts food such as pine seeds, walnuts, some plants burgeon and epiphyte. Generally, squirrels of Liangshui Nature Reserve only hoarded food in autumn, and pine cones, hazelnuts were main hoarded food. At hoarding period, each squirrel hoarded about 7077±927 caches averagely, and retrieved these cached when food shortage in winter, but the proportion of retrieving was just about 8%-17% of the total caches.The squirrel population of urban green area was small but with big density, and distributed at concentrated areas, so they had intense competition for food. In the course of hoarding, squirrels adopt the method of rapid isolation:they usually set up the caches around the food source for the purpose of obtaining more food during shortest time. Squirrels in Nature Reserve had obvious territories and usually selected big and full pine cones seeds for hoarding. The feeding experiment indicated that:in urban green area squirrels had no choice on the size and quality of pine cones originally, but squirrels can adopt the optimal method to carry and handle pine cones like squirrels in Nature Reserve after only 5 days, which showed the study ability of urban squirrels.