Possible Nutritional Deficiency of the Red Deer (Cervus elaphus) Population in the Wanda Mountains, Northeast China

Foraging analyses of red deer (Cervus elaphus) inhabiting the Wanda Mountains of Northeast China have indicated that the major food component of the population is leaf browse, with a low proportion of grass cropping. This form of feeding might complicate the transfer of energy and dry matter supply, possibly leading to nutritional deficiency and population decline. We measured the allantoin to creatinine ratio (A:C) of urine excreted in snow by free-ranging individuals of this population. In parallel, we used equations to calculate the digestible dry matter intake (DDMI) and metabolizable energy intake (ME!) of captive adult female red deer to evaluate the nutritional condition of the population. Between-year differences were found in the A:C ratio, DDMI, and MEI, which were 30.14%, 20.51%, and 35.39% higher in 2010 than in 2009. The DDMI in both sampling years was below the minimum wintering requirement. In 2009, the MEI ranged from 0.845 to 1.18 MJ ME/kg BM0.75, which would have satisfied the red deer energy requirement for approximately 70% of the adult females, indicating a slight shortage of energy supply. This variation appeared to be correlated with snow depth, which was lower in 2010 compared to 2009. Overall, the A:C ratio, DDMI, and MEI showed a significant negative correlation with snow depth. Food supplementation might be needed to fulfill the minimum nutritional requirement of red deer population, especially when snow depth reaches a threshold.