Abstract:

Background & Aim: Milu (Père David’s deer, Elaphurus davidianus) is a national key protected wild animal. Since its reintroduction in 1980, research on the diet composition of Milu has been a focus of researchers. We summarized the main feeding plants of Milu in the Beijing Milu Ecological Research Center, the Dafeng Milu National Nature Reserve, and the Shishou Milu National Nature Reserve. And we reviewed the common research methods of diet composition for animal including direct observation, utilization method, stomach content analysis, fecal microanalysis, stomach content or fecal DNA analysis and stable isotope technology and compared in terms of temporal scale, diet resolution, diet from the consumed stage, major strengths and major limitations. And, we analyzed the effects of ecological factors such as self-factors, plant nutrients and availability, and human activities on the diet composition of Milu. The analysis of the diet composition of Milu and common diet composition research methods aims to clarify the current progress of Milu diet composition research for promoting ex-situ conservation and natural return of Milu.

Review results: The main food source of Milu is plants. The food selection of Milu is influenced not only by self-factors, but also by the nutrient content and availability of feeding plants and anthropogenic factor. Physiological variation and alteration of energy requirements due to self-factors can influence the diet composition of the deer. Plant nutrients including crude protein, soluble sugars, and fiber are important factors influencing diet composition. Plant availability and anthropogenic factors further influence diet composition by changing food diversity and abundance. The comparative analysis of common diet composition research methods shows that different methods reflect different time scales and food resolutions in resolving diet composition, and there are corresponding advantages and limitations in the face of large endangered ungulates such as Milu.

Perspectives: We recommend that researchers should clarify the purpose and target population of the study. On this basis, researchers should reasonably assess the strengths and limitations of the available research methods, select appropriate sampling and data analysis methods to establish a reasonable diet composition research program. In future studies on the food composition of Milu, should focus on integrating the results of related studies on Milu, using a combination of methods to analyze diet composition, and comprehensively analyzing the food selection mechanism of Milu. This will not only guide the response of Milu to habitat fragmentation, wetland degradation and anthropogenic disturbance during reintroduction, but also further promote the development of Père David’s population and long-term conservation efforts.

Key words: Père David’s deer, diet composition, habitat, nutrients, diet analyses