Diet composition and selection of Père David's deer in Hubei Shishou Milu National Nature Reserve, China

<p><span>Hubei Shishou Milu National Nature Reserve is an ideal place to restore the wild population of Père David's deer (<em>Elaphurus davidianus</em>). </span><span>Understanding foraging ecology and diet composition is essential for assessing population development or establishing long-term effective conservation measures for endangered species.</span> <span>However, little is known about </span><span>the diet composition of </span><span>Père David's deer</span><span> and its diet selection mechanism</span><span>.</span> <span>In this study</span><span>, we used stable isotope technology to investigate the </span><span>diet</span><span> composition of Père David's deer according to various tissues (i.e., fur, muscle, liver, heart, and feces) and seasons, and evaluated the correlation between the nutrient composition of plants and </span><span>diet</span><span> composition</span><span>.</span> <span>Bayesian isotope analysis </span><span>showed that the autumn and winter diet estimated by fur and fecal samples indicated a diet dominated by C3 grasses (42.7 to 57.2%, mean), while the summer diet estimated by muscle and liver samples was dominated by C₃ forbs (30.9 to 41.6%, mean).</span> <span>The Pearson correlation test indicated</span><span> that the contribution of winter diet composition reflected by fur and fecal samples</span><span> was associated with correlations with crude protein (r = 0.666, P &lt; 0.01) and soluble sugars (r = 0.695, <em>P</em> &lt; 0.01). </span><span>The results indicated that crude protein and soluble sugars were important factors influencing the winter </span><span>diet selection</span><span> of Père David's deer.</span> <span>In the context of the current reintroduction facing many challenges, such as habitat fragmentation, wetland degradation, and human disturbance</span><span>,</span> <span>comprehensively evaluating the diet selection mechanism of Père David's deer under different resource</span> <span>specificities and temporal changes should be considered in the future</span><span>.</span></p>