After being kept in captivity and isolated from natural predators for more than 1,200 years, P6re David's deer has been reintroduced in China and now occurs in a reserve where human activity is the only potential thr...After being kept in captivity and isolated from natural predators for more than 1,200 years, P6re David's deer has been reintroduced in China and now occurs in a reserve where human activity is the only potential threat. Antipredator vigilance i~ an important component of survival for many prey animals in their natural habitat. Do deer still adjust vigilance as a function of risk after such a long period of relaxed predation pressure? Here, we examined vigilance levels in P6re David's deer groups as a function of group size, sex and level of human disturbance. The results showed that individual vigilance significantly decreased with group size in all-female groups but not in all-males or mixed-sex groups. In rutting season, males compete with one another and harass females, and we argue that vigilance is partly aimed at threatening males and that such vigilance increases with group size. This explains why overall vigilance did not vary with group size for males in general and for females in mixed-sex groups. Vigilance increased in more disturbed areas but in in male deer only. The results indicate that despite relaxed predation pressure over centuries, P6re David's deer can still adjust antipredator responses as a function of perceived risk. Such information may become useful in the rewilding programme now under way for this species in China [Current Zoology 59 (2): 265-270, 2013].展开更多
China is the ground for championing the survival of David’s deer. In ten years, the number of the endangered deer has increased six times, creating three world records of the number for David’s deer living in the wi...China is the ground for championing the survival of David’s deer. In ten years, the number of the endangered deer has increased six times, creating three world records of the number for David’s deer living in the wild, the species’ fertility rate and survival Located in Dafeng County, Jiangsu Province. David’s Deer Natural Preserve covers 1.000 hectares of land Established in 1986 under the sponsorship of the World Nature Fund and展开更多
In 1999, we observed six Père David’s deer calves (3 male and 3 female), which were born in the Beijing Milu Park to study the synchronization of action and grouping behavior in those calves. The observation beg...In 1999, we observed six Père David’s deer calves (3 male and 3 female), which were born in the Beijing Milu Park to study the synchronization of action and grouping behavior in those calves. The observation began in the second week of their births until their weaning, altogether, we collected 4 320 behavioral records. We established two indexes, the Index of Activity Synchrony, A, and Daily Frequency of Calves in the Same Cohort, P, for measuring aggregate behaviour in calves. Before their weaning, the calves synchronised their activity (A=0.87±0.006), and they stayed in same cohort most of the time (P=0.86±0.012). No sexual segregation behaviour was found in the calves. There were no significant differences of A (F=0.075, P=0.788, df=1) and P (F=0.489, P=0.497, df=1) in the calves of the same sex or between opposite sex. However, Index A and P changed significantly as the ages of the calves increased. Daily frequency of calves stayed in the same cohort could not present aggregation tendency of calves exactly. At 4 week old, calves expressed the highest activity synchronization.展开更多
基金Acknowledgements Financial support for this work was provided by the National Natural Science Foundation of China (No. 31000174 & No. Jl103512). We thank Prof. Ding Yuhua and other staff members at Dafeng Milu National Natural Reserve for supporting our field research in the reserve. We also thank Xianlong Li, Rongrong Wang, Jia He, Dameng Li, Ruonan Jia, Yilei Hua, and Long Wang for help with the field work, and Chen Ge and Cheng Huang for useful discussions.
文摘After being kept in captivity and isolated from natural predators for more than 1,200 years, P6re David's deer has been reintroduced in China and now occurs in a reserve where human activity is the only potential threat. Antipredator vigilance i~ an important component of survival for many prey animals in their natural habitat. Do deer still adjust vigilance as a function of risk after such a long period of relaxed predation pressure? Here, we examined vigilance levels in P6re David's deer groups as a function of group size, sex and level of human disturbance. The results showed that individual vigilance significantly decreased with group size in all-female groups but not in all-males or mixed-sex groups. In rutting season, males compete with one another and harass females, and we argue that vigilance is partly aimed at threatening males and that such vigilance increases with group size. This explains why overall vigilance did not vary with group size for males in general and for females in mixed-sex groups. Vigilance increased in more disturbed areas but in in male deer only. The results indicate that despite relaxed predation pressure over centuries, P6re David's deer can still adjust antipredator responses as a function of perceived risk. Such information may become useful in the rewilding programme now under way for this species in China [Current Zoology 59 (2): 265-270, 2013].
文摘China is the ground for championing the survival of David’s deer. In ten years, the number of the endangered deer has increased six times, creating three world records of the number for David’s deer living in the wild, the species’ fertility rate and survival Located in Dafeng County, Jiangsu Province. David’s Deer Natural Preserve covers 1.000 hectares of land Established in 1986 under the sponsorship of the World Nature Fund and
文摘In 1999, we observed six Père David’s deer calves (3 male and 3 female), which were born in the Beijing Milu Park to study the synchronization of action and grouping behavior in those calves. The observation began in the second week of their births until their weaning, altogether, we collected 4 320 behavioral records. We established two indexes, the Index of Activity Synchrony, A, and Daily Frequency of Calves in the Same Cohort, P, for measuring aggregate behaviour in calves. Before their weaning, the calves synchronised their activity (A=0.87±0.006), and they stayed in same cohort most of the time (P=0.86±0.012). No sexual segregation behaviour was found in the calves. There were no significant differences of A (F=0.075, P=0.788, df=1) and P (F=0.489, P=0.497, df=1) in the calves of the same sex or between opposite sex. However, Index A and P changed significantly as the ages of the calves increased. Daily frequency of calves stayed in the same cohort could not present aggregation tendency of calves exactly. At 4 week old, calves expressed the highest activity synchronization.