Diurnal behavior of Formosan Sambar on Alpine Grassland at Pans Mountain

• Main Authors: Jeng-Yan Guo, 郭正彥
• Other Authors: Ying Wang
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/26365138013579660650

碩士 === 國立臺灣師範大學 === 生物學系 === 93 === Sambar deer (Cervus unicolor) are the largest deer in East-Southern Asia, but very little knowledge about their behavior is known, especially the quantified field data such as behavioral time budget. From April 2003 to December 2004, the behavior of wild Formosan sambar (C. u. swinhoei) was observed on an alpine grassland at Pans Mountain, Central-Northern Taiwan. A total of 459 deer groups were sighted in 796.4 hours and the mean group size of sambar were 1.32deer/group. Sighting rates were significantly higher in summer and fall (0.91±0.49, 1.06±0.58 group/hr) than in spring and winter (0.49±0.32, 0.35±0.27 group/hr), and were highest in early morning (before 8 a.m.) compared to other five daytime periods. Grouping pattern of alpine Sambar has a trend to be solitary or in pairs all the seasons, while male sambar were more solitary than females and fawns. Sambar spent most of their daytime on foraging (61.73%) and less time on resting, ruminating, locomotion and other behavior. Compared to other two age-sex classes, female sambar spent more time on foraging and searching. However, females spent similar time on feeding with males and fawns. For female and fawn, the seasonal changes of foraging rates were not significantly different, but were greater in fall coincided with the rutting season for males. Based on our annual observation, the searching rates of sambar declined from spring to winter for males and females, but not for fawns. Foraging rates of sambar before bedding were significantly greater than the ones after bedding (P<0.001), and were attributed to the higher self-grooming rates after bedding (P<0.05). In spite of age-sex classes, searching rates of sambar were positively correlated with another indicator of food selection, the select index. Therefore, both indicators were representative of food selection for alpine sambar in this study. All three vigilance indicators of sambar were significantly different from each other when considering three sex-age classes of sambar, but only one of them, the intra-scan interval, conformed to our prediction that males were less vigilant than females and fawns because of their large body size and their sex-age-related weapon (antler). Besides, time spent scanning of sambar when foraging on grassland were significantly greater than the those foraging on forest edge, and the result were agreed to our observation about their fleeing response to shelter, the forest. Other biological factors, however, such as group size and composition did not affect the vigilance of sambar, except for an unusual result that the scan rates of females with fawns were lower than those without fawns. Time spent on resting or ruminating of sambar was nearly fifty-fifty after sambar bedded. On the other hand, mean time period of ruminating bout of sambar while bedding were significantly greater than those while standing. Among three sex-age classes of sambar, males spent more time on social behavior, which had a high proportion of marking behavior, than female and fawn. In addition, rubbing with antler was the most common marking behavior for male. Among three distinct sort of self-grooming behaviors of sambar, oral-grooming occurred most often (91.04%), followed by scratch- grooming (8.53％) and antler-grooming (only three times for males). Moreover, males spent less time on self-grooming, which might be reduced by their wallowing behavior with a possible function of removing ectoparasites. Sambar excreted their droppings with a posture of standing (45％) or walking (55％), and the defecation rates for adults were slightly greater than for fawns with a range of 8.16 to 13.92 (bouts/day). The degrees of ear flicking were significantly correlated with ambient temperature in spite of standing or bedding. Anti-predator responses before fleeing caused by observer were classified into tail-flagging (83.33%), snorting (59.52%) and stamping ground with forelegs (26.19%), and more than two of them could occur spontaneously. We classified foraging, locomotion, social and other behaviors as “active” phase and resting and ruminating as “inactive” one of sambar. Therefore, the average relative diurnal activeness of sambar was 72.75%. On this alpine grassland, we believed sambar were more active than on other unstudied habitats. During daytime, the more active hours of sambar were at 10 a.m. and 16 p.m. while less active ones were at 6 a.m., 11 a.m., and 17 p.m. Furthermore, relative diurnal activeness was lower in winter and summer than other two seasons, but no differences were detected between sunny and cloudy days in our analysis.