关键词: 熊猴, 姿势行为, 季节变化, 日变化

Abstract: Positional behavior studies have vital importance for understanding the adaptation mechanism of primates to their habitat. To explore seasonal and daily variations of Assam macaques (Macaca assamensis) positional behavior and the influence of food composition and ecological factors on this type of behavior, we collected positional behavioral data via instantaneous scan sampling method from September 2012 to August 2013 at Guangxi Nonggang National Nature Reserve, located in southwest China. The quadrupedal walking (45. 3% ±7. 6%) was observed as the most frequently used locomotion mode, followed by leaping (28. 8% ±4. 8%), climbing (23. 9% ±6. 2%), quadrupedal running (1. 2% ±0. 7%) and bridging (0. 9% ±0. 6%), with a significant difference. Locomotion modes varied significantly between seasons. Assam macaques used bridging more frequently in fruit-rich season but used climbing less during the fruit-lean season. However, the other modes of locomotion did not significantly vary in the different seasons. Assam macaques were documented to climb more often in the afternoon than during the morning period. There were also significant variations in the macaques' postures. Specifically, sitting (91. 7% ±4. 1%) was the dominant posture, followed by standing-forelimb suspending (4. 2% ±3. 3%), suspending (1. 9% ±1. 6%), quadrupedal standing (1. 4% ±1. 8%), and lying (0. 8% ±0. 5%). In addition, we observed a variety of significant different postures during different activities. For instance, sitting (87. 3% ±6. 1%) and standing-forelimb suspending (7. 9% ±5. 5%) was the dominant postural modes for feeding, sitting (95. 6% ±2. 8%) and lying (3. 1% ±2. 2%) was the dominant postural mode during the grooming behavior; and sitting (97. 1% ±1. 4%) and quadrupedal standing (2. 2% ±1. 1%) was the dominant postural modes observed during the resting periods. There was no significant seasonal variation in observations related to the different postures of this group of macaques. Lying and suspending posture were more frequently used in the morning (06:00-11:59) than during the afternoon (12:00-19:00). Nevertheless, diet and ecological factors were important parameters that affected the positional behavior of macaques. We established both model I (including fruits) and model II (including immature leaves) to test the effects of diet composition on the positional behavior of Assam macaques. These results provided evidence of the effects of diet and ecological factors on the positional behavior of Assam macaques. This study highlights the necessity to increase the knowledge of behavioral ecology and to understand the influence of ecological factors on the survival of Assam macaque in the limestone forest.

Key words: Assam macaque (Macaca assamensis), Positional behavior, Seasonal variation, Daily variation