Prey Recovery For Amur Tiger In The Changbai Mountains-Adaptability Of Sika Deer Reintroduction

The lack of preys dramatically limits China’s wild tigers from surviving and recovering. In the habitat of Amur Tiger in Northeast of China, the density of the main prey, the Sika Deer, is as low as 0.1 individual per km2, and it is insufficient, therefore a project to re-introduce wild deer and facilitate a stable settling of a population was carried out.In 2012 and 2013, in the National Natural Protection Area, in Wangqing, Jilin Province, the author kept 63 captive Sika Deer in to a transition field for one month, and then released them. In 2012, from June to August, and in 2013, from June to August, a monitoring of the deer population was carried out in order to make a study on their adaptability; this study provided essential information and technical guidance for the future prey recovery.The main conclusions of the study are the following:1. By means of fecal analysis, the diet composition of the re-introduced sika deer during the transition period was studied; it was found that the main intake was composed of 12 families and 31 genera, of which Salix, Populus, Quercus, Betula and Artemisia is 46.48%, accounting for the main food intake. In the first 5 days of transition, food composition is highly correlated to the wild plant availability; after 10 days, a stable food preference was eventually formed. The stable compositions of food preference between re-introduced and wild deer were compared and the result showed that no the difference was not significant.2. As for the extraction and determination of cortisol content of the re-introduced sika deer, the results showed high and unstable levels in the feces (588.3ng/g±93.4), in the first 10 days, this indicates a strong stress response. However, its content decreased as a whole and,10 days later, its content stabilized at about 355.10±63.1 ng/g, which compares to the cortisol content of local wild deer. During this study, no sika deer experienced health issues due to stress; the stress response of the population in a non-predatory environment can reliably be eliminated in 10 days.3. From the behavior standpoint, instantaneous scanning methods were used to study the change in behavior during the transition period. The results showed that, in the first 10 days, the fluctuations in behavior time budget is higher; certain activity rhythm are recorded, but not in a stable way. In the transition field, after 10 days the activity rhythm stabilized into comparing to wild deer’s activity rhythm. It is worthy of note that the re-introduced sika deer, in the first 10 days, engaged more in to watching behavior than in foraging, indicating a high stress response. In the following 5 days, the foraging increased, the watching is still high, rumination is low; this is a key period, because of the influence of stress response on rumination, if not timely adjusted, may fatally affect on the deer’s metabolism.4. After 1 month in the transitional field, the deer were released in to the wild, and they were monitored by means of radio collars in order to carry out a habitat selection study. Meanwhile, by using automatic infrared camera, the local wild deer habitat selection was also studied. The results show that the re-reintroduced deer prefer slopes less than 25°, low shrub and tree density. Besides, the distance-to-water is as close as <500 m. Their preference is consistent to the sympatric deer’s in that they have the same tendency to choose small gradients and areas with a moderate tree density. However, the wild deer pay more attention in avoiding predators; in fact, they prefer to go upslope, walk longer distances to keep far from human disturbance and local human communities. In addition, the PCA analysis of re-introduced sika deer showed larger absolute coefficient related to slope, slope position, distance to water, and canopy; so these factors should be given priority in the study of the habitat selection.5. Generally, the fluctuations in behaviors due to stress adaptation in re-introduced sika deer are eliminated in 10 days, and then adjust to the norm. Therefore, in terms of management, a more stringent monitoring and a possible human intervention may be necessary at this early stage; it should also be arranged by employing trained and qualified staff, with good job preparation. As for the released sika deer, some differences with wild deer will still exist, especially in the predators’ avoidance; the management staff should promote the aggregation of the re-introduced sika deer with groups of wild deer, so that the adaptation process is accelerated.