Feeding Ecology Of Giant Pandas In Simple Bamboo Feeding Habitats In Taibai Mountain

Taibai Mountain Nature Reserve is the northern boundary of giant pandas' distribution range. Although there grow both Bashania fargesii and Fargesia qinlingensis, giant pandas in this reserve only feed on Fargesia qinlingensis as a result of human activeities. Such a feeding habitat have provided a relatively ideal environment for this study, namely simple feeding bamboo feeding habitat, which has been proved by the finding that giant pandas' feeding habitats there are only covered with Fargesia qinlingensis.During the summer and autumn-winter in 2005, field investigations were conducted in Haitanghe (Huangbaiyuan Protection Station) and Longdong Gully (Houzhenzi Protection Station), both of which lie in the core area of National Taibai Mountain Nature Reserve in Shaanxi Province. To reveal the real situation of the panda population structure and the characteristics of feeding habitat, parameters, such as length of biting size, short diameter of feces, bitten bamboo, feeding station and feeding habitat, were qualitatively or quantitatively measured in the field or laboratory. For the first time, discrimination analysis was used to reveal the Panda population structure, and hierarchical habitat selection theory was applied to the analysis of pandas' feeding habitat selection in single bamboo feeding habitats. According to the analysis of nutrient content, feeding strategies in different seasons were concluded.Several statistical methods are applied to rigorous and in-depth data analysis as follows: (1) Firstly, panda's ecological age was defined according to age function which could be obtained by discrimination analysis, and the population structure and number and distribution were then concluded using maximal variance of the length of biting size;(2)The six compound principle components were built according to PCA analysis (Principle Component Analysis). Then, by using Vanderploge & Scavia selection coefficient (V&S method), the optimum ecological niche of each ecological factor was confirmed. Finally, the optimum feeding habitat model was established;(3)Descriptive statistics is used to explain the characteristics of feeding station. Panda's food recipe is affirmed by feces analysis, and V&S method was used to define the selection of bamboo age, basal diameter and different bamboo nutritionorgan;(4)Contents of six nutritious substances in Fargesia qinlingensis were measured in laboratory and analyzed quantitatively. Linking to hierarchical habitat selection theory, the feeding strategy of pandas in Qinling Mountain was systemically discussed and analyzed for the first time.Pandas in Taibai Mountain formed a series of optimized feeding strategies in response to feeding habitats, feeding stations, feeding individuals and moving behavior. The conclusions were the follows:1. The results showed that there are sixteen pandas living in Taibai Mountain Nature Reserve, including five post-adults, there adults, four sub-adults and four cubs. So the structure of age pyramid indicated a trend between stable and declining.2. The adaptive and selecting process was demonstrated at three levels, namely optimum feeding habitats, feeding stations and feeding individuals. First, pandas search for optimum feeding patches and feeding stations, and then would largely or quickly capture and ingest nutritive bamboo organs and optimum basal diameter of bamboo individuals.3. Seasonal changes of pandas' feeding strategy occur in Taibai Mountain Nature Reserve, which may be directly linked to the periodic change of the nutritive and energy condition of bamboo forest. The optimized feeding strategy is to fit the food condition of feeding habitat.4. The optimized feeding strategy shows a trade-off between investments and profits at three levels. The feeding strategy was not invariable, since seasonal regulation and differentiation occur from the summer to autumn-winter. However, the common feature is that optimum feeding habitats are selected and utilized. The seasonal changes are demonstrated in several aspects. First, top-quality feeding stations are chosen and then quickly utilized with high utilization ratio for feeding individuals in the summer. In autumn-winter, the nutritive condition in feeding station is relatively poor, and in response, pandas can meet the basic requirement of energy and nutrition by enlarging the diameter of feeding station, elongating utilization time, and improving the utilization ratio of feeding station.5. Pandas in Taibai Mountain Nature Reserve live in mid-mountain range (2201-2601m). Seasonal movement is not obvious, due to interaction between internal and external reasons. The external reason is mainly strong human activities, while the internal reason is the simple bamboo feeding habitat. The most important is thatunreasonable human activities and poor management practice compel pandas to move back to Bashania fargesii forest habitat.6. From the perspective of sustainable development of reserve-community compound system, based on the theory of social-economic-natural compound system, a series of objective and feasible management thoughts and means, such as the acceptable level of economic activities and boundary preservation, are expected to promote the project upon giant pandas and the whole natural conservation to some degree.